Cineman - #01748 3.0lt twin turbo - Italy

[cineman]

Hello all!
Invited here to contribute to the EFI discussions ;)

On my 3.0lt PRV, evenfiring, I'm using a factory Renault ECU, called "Fenix 3A" .
Is the same kind of ECU that the original engine came from the factory, but from another car, cause the original one was lock coded.

There are really few informations about this ecus on the web, and there are lot different types ( Fenix 1, 3A, 3B... etc ).
Is quite easy to modify the fuel and timing maps, but all the other values are not always known, and some forums exist for this Fenix informations, but is not so much.
I think it should be similar to the original ECU of the Eagles 3.0 engines.

I plan to pass to megasquirt in the future for this problems: i can make it run nicely but i have problem with the cold enrichment and external temperature, sometimes it goes too rich and at the moment i cant find how to modify in the Eprom.
Or I completely change the maps in the winter ^_^

Tuner Pro, the software for mapping i'm using.
https://lh6.googleusercontent.com/-1Mc2m-FMDlI/Tdz4e8lmjJI/AAAAAAAAHFU/kz83dEtuyeM/s640/ECU_BTO.JPG

A naked Fenix 3
https://lh5.googleusercontent.com/-hss1WsMBo9k/TdzntjveCkI/AAAAAAAAHEc/Q01UEZJADCg/s512/Foto0522.jpg

Some shot of the mess... i usually put things in and i make them nice just in the end ;)

Engine before the intercooler
https://lh6.googleusercontent.com/-Fk-OGY3N8vY/TfEZvbFHS0I/AAAAAAAAHLQ/3EAKW9dQZMc/s640/DSCN1572.JPG

ECU and wiring. It works! :D The little card is a TTL-USB adapter for reading the data stream of the ECU.
https://lh4.googleusercontent.com/-FyI0nUtGKmY/TfEZvYF1uEI/AAAAAAAAHLU/FOHYxZCeLx4/s640/DSCN1574.JPG

3.0 Intake
https://lh6.googleusercontent.com/-i-vbPg92WhM/TfEZsBWYCVI/AAAAAAAAHLE/IbI1FP1r_wY/s640/DSCN1563.JPG

[jerzybondov]

Amazing stuff Andrea! Am I right in thinking that your engine came out of a Safrane Biturbo? Did you have to ditch all the original EFI setup and put on your own to make it work in the DeLorean?

[dmc6960]

Am I correct in assuming that is the single-chamber plenum intake manifold? (Like the B280 and Eagle engines) Not the dual-plenum one?

[cineman]

It is MAINLY based on the Safrane Biturbo engine, but is lot more modified. In the other topic in the custom page there's the list of the things from what engine and what from others ( Safrane, Alpine, Espace etc ).
The engine management and electric loom is not from Safrane, just the big fuel injectors. All the electrical, sensors etc is redone.

The intake is the single plenum like the 3.0lt versione you have in the USA.

[jerzybondov]

Andrea - this may seem like a stupid question - but can I ask why you've had to go as custom as you have? To what extent was this level of customisation essential to make the engine work? How much of it was your choice to optimise the engine's performance in this installation? Because peak power is similar to the original Safrane unit isn't it?

For anyone thinking of doing anything similar it would be nice to know what the simplest way of doing a swap like this would be - it may well be that yours is the simplest, I just thought I'd ask!

[cineman]

Andrea - this may seem like a stupid question - but can I ask why you've had to go as custom as you have? To what extent was this level of customisation essential to make the engine work? How much of it was your choice to optimise the engine's performance in this installation? Because peak power is similar to the original Safrane unit isn't it?

For anyone thinking of doing anything similar it would be nice to know what the simplest way of doing a swap like this would be - it may well be that yours is the simplest, I just thought I'd ask!

Quite all the customization is just for adapting the engine to fit the Delorean. As usual there is the lower crankcase swap for fitting another PRV to the delorean, and in this case also modified for the turbos oil returns.
An engine directly taken from a Safrane will never fit in dimensions, oil and water connections, and also exahust and turbos, wich on the safrane are completely different, also because the engine is mounted transversal in the car. the two headers of the safrane are one very different from the other and also the 2 turbos and will never fit the delorean. The same for the original intake system.
The power is very similar because in fact i have no big mods in the most important things of the engine: pistons, heads, cams...are right the one of the safrane, and the turbos i'm using are really a bit smaller than the safrane's one, but i'm pusing more PSI.
Another differences are the valves and timing cover: for using the Delorean AC compressor for exaple i cant not keep the Safrane one. The Safrane also use a balancing mechanism on one of the heads for the position of the engine, and i took it off. For using the Alpine valve cover, wich are similar and the AC suit to them, i had to grind some casting inside them to be clear with the valves tappets.
The Safrane engine also has a REAR spark distributor, and with our dome suspension bar it would not fit, and i used the Alpine timing cover because it has a front hole for another spark distributor...
I tried lot of different solutions, and this is my 2nd turbo PRV in the car, but in the end i came to the end that the most original parts i use from Renault, the most i'm sure they works and cause no problem ;)
That's one of the reason i prefered to find a turbo PRV from factory, even if it was not cheap to find out.

[jerzybondov]

Very impressive stuff Andrea!! :D

[cineman]

Hi guys,
I bought a megasquirt II, v3 kit for saying goodbye to the original renault ECU :)
I think i will receive the kit in the next week... i started to read manuals and download software but is still a bit obscure where i have to start... i'm sure you will have suggest to what i can read first, during this days i wait ;)
I think i will use TunerStudio.
I know i will have to test and use the "Renix 44-2-2" trigger.
I have low impedance injector, i will have to make some PWM settings...or do you suggest to use resistors ?
I was planning to put in all the fixed value i know, and use my old values of fuel and timing from the other tuner program i had, i should get something working... than i should work on the things i dont know and experiment with cold enrichment, accell enrich, and all the correction.

I did put a pair of quick build intercoolers for now, but i want to design and make 2 complete coustom ones to use most area i can in the future.

https://lh6.googleusercontent.com/-8_HJzsRJbZs/TwSsIBqJxXI/AAAAAAAAHu4/Fn1TUJ0yx7A/s640/IMG_0123.JPG

[Domi]

Awesome job, as usual :smile:

[SIMid]

This is one beast of a Delorean! :) Awesome job and awesome mods!! :evilgrin:

[Spittybug]

Hi guys,
I bought a megasquirt II, v3 kit for saying goodbye to the original renault ECU :)
I think i will receive the kit in the next week... i started to read manuals and download software but is still a bit obscure where i have to start... i'm sure you will have suggest to what i can read first, during this days i wait ;)
I think i will use TunerStudio. Buy the full version, you will love the real time auto tune feature
I know i will have to test and use the "Renix 44-2-2" trigger.
I have low impedance injector, i will have to make some PWM settings...or do you suggest to use resistors ? Make sure you have the flyback circuitry in place. There are also some settings on the injectors setup page that are a little different for low impedance.
I was planning to put in all the fixed value i know, and use my old values of fuel and timing from the other tuner program i had, i should get something working... than i should work on the things i dont know and experiment with cold enrichment, accell enrich, and all the correction.


It looks great! I think that once you get familiar with MS you will love it. Use the forum boards to get more help. There is currently a lot of work going on to improve the idle condition when loads kick in (such as A/C). A combination of idle advance and idle air controller movement looks to be the solution. Stay tuned (no pun intended!)

[cineman]

Ok, kit arrived and i'm mouting it.
Already did the first comunicaitions test and all is ok.
My first quest: for using and idle motor like the original 3 wires, what setup did you installed ? the one for PWM idle valve? i dont think is stepper, or i'm wrong ?
tnx !

[dmc6960]

My first quest: for using and idle motor like the original 3 wires, what setup did you installed ? the one for PWM idle valve? i dont think is stepper, or i'm wrong ?
tnx !

Easiest solution is to ignore idle control on the Megasquirt, and leave the stock computer/motor in place. Use a configurable output from the Megasquirt to simulate the idle switch. It would be very difficult to get Megasquirt to match or exceed the original idle capabilities of this car.

[cineman]

Easiest solution is to ignore idle control on the Megasquirt, and leave the stock computer/motor in place. Use a configurable output from the Megasquirt to simulate the idle switch. It would be very difficult to get Megasquirt to match or exceed the original idle capabilities of this car.

thanks dmc6960, but i dont have an original engine and setup on my car: I'm replacing a renault "renix" ecu for my 3.0, and this ecu controls an idle motor 3 wires like the one on the delorean, but i dont have a separate idle ecu, so i have to control it with the megasquirt. If is not possible, i will have to not use it or find another type of idle motor, but i would like to keep the harness and sensors i already have for this ecu :)

[dmc6960]

I knew your engine isn't stock, but at some point you had a stock idle ECU though, right?

Megasquirt with a few mods CAN control a 3-wire PWM idle motor, but it will not be as refined as the stock computer.

If you no longer have that ECU then may I suggest Dave's new ECU...
http://dmctalk.org/showthread.php?148-Microprocessor-controlled-idle-ECU
Since your directly splicing wires anyways, there would be no need for an original ECU housing, just put in a generic box. The idle control only needs 3 pieces of hardware. Temp sensor (thermistor in coolant Y-pipe), ECU unit, and idle motor. Only parts I don't know for sure is the compatibility between your existing motor and the DMC/Volvo ones Dave designed his unit around, and I don't think it's been tested on an even-fire engine since Dave optimized the tach sense for the odd-fire.

[cineman]

I knew your engine isn't stock, but at some point you had a stock idle ECU though, right?

Megasquirt with a few mods CAN control a 3-wire PWM idle motor, but it will not be as refined as the stock computer.

If you no longer have that ECU then may I suggest Dave's new ECU...
http://dmctalk.org/showthread.php?148-Microprocessor-controlled-idle-ECU
Since your directly splicing wires anyways, there would be no need for an original ECU housing, just put in a generic box. The idle control only needs 3 pieces of hardware. Temp sensor (thermistor in coolant Y-pipe), ECU unit, and idle motor. Only parts I don't know for sure is the compatibility between your existing motor and the DMC/Volvo ones Dave designed his unit around, and I don't think it's been tested on an even-fire engine since Dave optimized the tach sense for the odd-fire.

Ok, i still have the original idle ecu and sensor around, but i take everything off the car. I dont have more an original Y pipe, so no hole for it ^^ and i will need to put it somewhere, if i use it.
But i still would like to try to use the Megasquirt, do you have more informations or link about using the 3 wires motor ?
My idea is that i have a Renix renault harness now, and i would like to keep it this way so in case of ECU problem i can quickly switch back to original Renault ECU . I will be have an adapter for attaching the megasquirt to the same Renault connector. Any info on running the 3 wires is appreciated ;) thanks again for the help !

[Spittybug]

Cineman..... the MSII unit is fully capable of driving a GM style stepper idle air controller valve (4 wire) right out of the box. The key is the creation of the correct housing to hold the IAC. This shows you a generic one that can be mounted anywhere: http://www.diyautotune.com/catalog/custom-idle-air-control-body-for-use-with-jeep-40l-iac-valve-p-69.html Attached are a couple of shots I just took of the first one we have built for the stock engine conversion project. Either one will accept an IAC such as this: http://www.ebay.com/itm/IDLE-AIR-CONTROL-VALVE-IAC-AC174-/320828261571?pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr&hash=item4ab2dac4c3#ht_2624wt_1139 There is NO benefit to paying for an expensive version of this thing, they are all comparable to the best of my knowledge. The nose, or pintle, moves in and out in the hole of the aluminum block. The megasquirt has a setup page to precisely define how many "steps" to fully seat (no air) and how many to back off (open) depending on the engine temperature.

Jim (and others) are strong proponents of keeping the stock idle air controller. I have no issue when they work well, but many seem to be failing with age. The pipe that the cold start valve sits on and continues down under the fuel unit to the manifold hole is also in the way for our stock conversion design (gets in the way of the fuel rail) and we don't need the cold start anyway. The above part is cheap and easy to replace and fully configurable using megasquirt.

Looking forward to hearing about your progress.

[cineman]

I understand the reason around an original engine with his intakes and hoses, but my preference would be not to change my actual idle speed motor. wich is very similar to the delorean OEM but more modern: i already have a complete EFI system, ecu, harness, sensors, tps on the car...all OEM Renault, adapted from various PRV engines... wich controls everything, but the ECU Renix is not enought known to modify particular values like accell enrichment and others: that's why i'm going to megasquirt, to have a complete control and not just fuel and timing tables ;) ...so it would be a pity to change my actual idle motor, hoses... cause if i need i can't put again the OEM Renault ECU, and i have more than once spare, and also i have a Renault Alpine GTA turbo, so i cross parts around cars... does someone knows a link or documentation about modify on board or software i can do to make at least work a bit a 3 wires motor ? dmc6960, you said it work not good like the original system, but working would still be better than not working at all ;)

[cineman]

Ok, maybe i think i have to use the PWM idle system 2wires of the MS, but use another output with the same pwm frequency but with the complementary pulse witdh...each of the 2 output to the side of the motor, center to 12v... it seems someone did it and it works...

[Bitsyncmaster]

I knew your engine isn't stock, but at some point you had a stock idle ECU though, right?

Megasquirt with a few mods CAN control a 3-wire PWM idle motor, but it will not be as refined as the stock computer.

If you no longer have that ECU then may I suggest Dave's new ECU...
http://dmctalk.org/showthread.php?148-Microprocessor-controlled-idle-ECU
Since your directly splicing wires anyways, there would be no need for an original ECU housing, just put in a generic box. The idle control only needs 3 pieces of hardware. Temp sensor (thermistor in coolant Y-pipe), ECU unit, and idle motor. Only parts I don't know for sure is the compatibility between your existing motor and the DMC/Volvo ones Dave designed his unit around, and I don't think it's been tested on an even-fire engine since Dave optimized the tach sense for the odd-fire.

It should make no difference with my ECU or the stock ECU running even fire or odd fire. Both ECUs use the timing of two tack pulses to read RPM.

[Bitsyncmaster]

Ok, maybe i think i have to use the PWM idle system 2wires of the MS, but use another output with the same pwm frequency but with the complementary pulse witdh...each of the 2 output to the side of the motor, center to 12v... it seems someone did it and it works...

That is correct. The PWM is a constant frequency 100 Hz for stock ECU, 61 Hz with mine. The second PWM driver is just the complement of the first.

[cineman]

Some MS friends gave me this schematic for controlling the 3 wires using the single Fidle output of the MS.
Does some tried or know it ?

http://www.glensgarage.com/3wire/Idle-Coil_Board_schematic.pdf

or this solution using a big power resistor:

http://www.msextra.com/doc/ms2extra/MS2-Extra_Hardware.htm#Fidle

[Bitsyncmaster]

Some MS friends gave me this schematic for controlling the 3 wires using the single Fidle output of the MS.
Does some tried or know it ?

http://www.glensgarage.com/3wire/Idle-Coil_Board_schematic.pdf

or this solution using a big power resistor:

http://www.msextra.com/doc/ms2extra/MS2-Extra_Hardware.htm#Fidle

The first circuit would work but you need a driver (from the MS) that provides 0 and 12 volts.

The second circuit would work if your drivers can provide enough current.

The resistor.....no

I use N-channel MOSFETs with diode and zener suppressors that drive directly from my micro (0 to 5 volts). If you use a power transistor you will need about 50 ma. of drive current for a typical hfe of 20. The idle motors draw about 500 to 1000 ma.

[cineman]

Hello guys,
i made the adapter for connecting the MS to my actual harness and did the first tests.
I had some problem having a good trigger input: i use a VR sensor, the oem renault one on the flywheel ( I use the Renix 44-2-2 standard ) i started with the 2 potentiometer all clockwise like the manual says and got no signal, then started turning then little by little clockwise until the ECU started to see a RPM signal, and got the car idling on the MS.
I did a lot of tuning on them, but i still think i dont have a very good VR signal :
I can hear every few secs the Fuel pump relays switch on-off, and the idle is very unstable and oscillate, i think for the RPM signal input wich switch the pump on and off. I also see the MS software going Synched-Not synched, when this appens.
I tried to open a little more the air but i still dont have a stable idle even at about 1000rpm.
Do you have suggest how to regulate that potentiometer ? I saw someone using an external signal amplifier for this kind of VR sensors, what do you think ?

I also use PWM for controlling the injectors, i started with PWM at 30% and 1.0ms of threshold, and it seems fine. Tried to lowered it, cars die at about 12% and 0,6ms but not start anymore after, so i think i keep the suggested numbers. Changing this dont change the quality and oscillation of idle, so i'm quite sure is more an RPM input problem ;)
Thanks guys! This seems to be a very fun project :) I get excited every time i see a real time numbers on the PC lol :D :D

[cineman]

Ok... found the potentiometer problem, i just soldered them the opposite way ;)
I will do more test in the evening, I'll let you know!

[cineman]

Hello!
Some little progress during this times. I got the WUE, cranking and priming curves quite good and working with frozing out temperature, and even the fuel maps for now seems not so bad, but i have just the narrow band sensor on, now, wich is btw working and making some EGO corrections when all is warmed up.

The problem i have is still a random big "miss" , suddenly die for a second, on the engine, when accelerating, cruising or so. I thought it was the VR sensor sensibility problem, but now that seems to work and read good and it has good graphs in the logger, so maybe could be a power supply problem ? I get my supply from my old main supply of the other ECU and that one was working, but i see in fact some times the volts reading of the MS read peaks of quite high voltage ( around 16 volts )
Do you have tests to try out to find the area of the problem ?

I attach also my MSQ file
8606

[Spittybug]

Cineman, I wasn't able to open your file for some reason. What version is it? In any case, it sounds like maybe you are getting a reset.

Is your fuel pump on the same circuit as your Megasquirt? It's not a good idea since mechanical devices are "noisy" and can disrupt the MS. I ran them on two separate circuits. For the conversions I am now helping with, we run 2 fused wires from the battery; one dedicated to the fuel pump relay and the other providing power for the MS, the O2 sensor and the injectors. I haven't heard anyone having problems with the mechanical fuel injectors creating noise on that circuit, but I suppose it is possible.

Check the obvious too, the grounds. All MS grounds need to go to the same spot. Make sure that block is well grounded and that your negative batter cable is firmly connected at your trailing arm bolt (my ring connector was free spinning on the wire!).

[opethmike]

Cineman, I wasn't able to open your file for some reason. What version is it? In any case, it sounds like maybe you are getting a reset.

Is your fuel pump on the same circuit as your Megasquirt? It's not a good idea since mechanical devices are "noisy" and can disrupt the MS. I ran them on two separate circuits. For the conversions I am now helping with, we run 2 fused wires from the battery; one dedicated to the fuel pump relay and the other providing power for the MS, the O2 sensor and the injectors. I haven't heard anyone having problems with the mechanical fuel injectors creating noise on that circuit, but I suppose it is possible.

Check the obvious too, the grounds. All MS grounds need to go to the same spot. Make sure that block is well grounded and that your negative batter cable is firmly connected at your trailing arm bolt (my ring connector was free spinning on the wire!).

+1. I was having a huge number of reset problems until I followed Owen's advice. Mr. Malbec is THE man on this topic.

[Spittybug]

:thankyou:

In the immortal words of Garth, "I'm not worthy!!!!!!!!!"

Hey, I'm a believer in modernizing the guts of the car while maintaining as much of the classic aspects as you would like. The fact is that most people either can't diagnose the various components of K-jet themselves or can't afford to have others do it for them. I have nothing against the carburetor camp, but to me, that's a step in a direction I would rather not take. If I can minimize the moving parts, the things that will wear or the things that fewer and fewer people understand and can help with, all the better. There are diagnostics to trouble shoot software problems and plenty of help on forums. If you know injectors are injecting, it's merely a case of making sure they do it correctly. Tuning your car with software is a hell of a lot better with a laptop than it is with a wrench in my opinion! I wholeheartedly encourage each of us that are EFI'd to post their .msq files and to maybe also snapshot their tables. I haven't fully explored the software aspects of reading .msq files and loading into projects..etc... but it isn't hard to copy/paste tables. VE, AFR, ADV, ASE, WU. Done.

Rock on dudes! :doorpeek::grouphugg:

[opethmike]

Once I get ~100 miles or so on my newly Spec 2'd engine, I'll post the MSQ for it. Should be useful as a base tune for other Spec 2s, or for a Stage 2, which is similar, but not as aggressive.

[cineman]

Today i did some works, i routed different power connection, got a separate relay just for the fuel pump getting power directly from the battery, i also tried changing and getting a new ground wire for the ECU directly from the battery also, but got no improvments: i still have big miss. I touched again the 2 potentiometer and i surely see that moving then the problem get worst or better.
The better is still when they are all anticlockwise, but this get me that i still have a RPM reading problem.
When i have this miss on the ignition, fuel goes in the exhaust and when suddely reappear ignition i get big flames out of the exhaust ;) but i dont want to risk more, i need to resolve this.
How can i see that this is the real problem ? Looking at the tooth or trigger analyze what can i look for ?
I think my solution will be to get a VR amplifier circuit, i see some sensors need this, cause the stock VR amplifier is not enought in some cases...

someone got success in reading my msq ? should firmware 3.21 if i remember good.

[Spittybug]

I got it open.... Req. fuel of 10? Way low. I'm a normal aspirated stock engine and my required fuel is 18 (9 for 2 squirts). That is making your VE table values much higher. I don't know if that in itself is a problem (certainly the fuel for your Batmobile flames out the exhaust), but it can't be helping.

When is the problem, at idle, cruise or during boost? I'm no expert on these things, but I also think that your advance past 2800 RPM may be too aggressive. You've got values going up to 52*. I know that you aren't using our engine, but everything I've learned says to stop at 37* or so for ours. Is yours that different? Pre-detonation might give the symptoms you describe as a miss.

Do you have any log files to share? They will let us see better what is happening. If you haven't done so yet, go to the megasquirt forums www.megamanual.com and look on the left hand navigation pane for the forums. LOTS of very smart people there that helped me with my install.

[cineman]

the reqfuel i did 2 times the calculations, seemed low to me also but with the input data that was the output ^^ but i think i missed something, I'll take a look.
About the timing, i think 37deg with a stock engine is still lot conservative.
I have the original maps from OEM renault engine, turbo and not turbo, and they goes up to 52deg in oem maps, 60 deg in a sport racing maps i have from Renault, all for PRVs.
During the night thoughts i think i discovered my problem ;) now i'm at work, but today late i will try what i have in mind and see if the problem will go away...
I'll let you know! Thanks Spittybug ;)

[cineman]

I got it open.... Req. fuel of 10? Way low. I'm a normal aspirated stock engine and my required fuel is 18 (9 for 2 squirts). That is making your VE table values much higher. I don't know if that in itself is a problem (certainly the fuel for your Batmobile flames out the exhaust), but it can't be helping.

about the reqfuel, maybe i'm missing something but if i put my data inside i get even lower than 10, but around 7. Can you try to test this numbers for me ?
My displacement is 2965 cc , 6cyl ;) , and my injectors are rated at 450cc/min ( around 40lbs? ) ( maybe is this big number that give me lower number ? )

[Spittybug]

Ok, your injectors are twice the size of mine. I get similar numbers when I plug them in.

Any luck capturing a log file? What did you think of that you intend to try?

[cineman]

Ok, i did the modify and tests i had in mind: i tought i had the VR sensor in the wrong polarity, i tried to swap and check again but it was ok, and if i reverse it have even mor problem in keeping it running.
So i tried also to put a 10Kohm pullup resistor from 5v for the vR sensor like in some application need: this seems to me to have a little better and lot less sensible to the 2 pot position, but i still have the random "miss" at some rpms.
I tried to show up the Synch Error counter in the dashboard but it does not move... so maybe is not a sync problem ^^ but i dont know...
I put my oscilloscope 2 channel connected to the VR sensor and to the VROUT and it seems to me I have a quite good signal there, i played a bit with the pot also to make it the best i could,
I recorded a quick MSL , starting to idle and accelleratin slowly to about 2500rpm with costant gas, and i have quick falling in rpm sometimes... so maybe is not a sync problem, can you take a look ?

8675

[cineman]

Ok, i did the modify and tests i had in mind: i tought i had the VR sensor in the wrong polarity, i tried to swap and check again but it was ok, and if i reverse it have even mor problem in keeping it running.
So i tried also to put a 10Kohm pullup resistor from 5v for the vR sensor like in some application need: this seems to me to have a little better and lot less sensible to the 2 pot position, but i still have the random "miss" at some rpms.
I tried to show up the Synch Error counter in the dashboard but it does not move... so maybe is not a sync problem ^^ but i dont know...
I put my oscilloscope 2 channel connected to the VR sensor and to the VROUT and it seems to me I have a quite good signal there, i played a bit with the pot also to make it the best i could,
I recorded a quick MSL , starting to idle and accelleratin slowly to about 2500rpm with costant gas, and i have quick falling in rpm sometimes... so maybe is not a sync problem, can you take a look ?

8675

taking a look at my log file, seems to me that the fall in the rpm is next to some large PulseWidth signal.. why do the PW should make this random big numbers?? TP is costant, map signal is costant... i will start to think about :)

edit: OK i did some thought and turned completely off my accelleration enrichmet and this seems to solved the random PW :)
Now i will did more test and see on the road the next steps ;)
I like MS options lol.

[Spittybug]

You are making good progress Cineman. I will take a look at your log, but your comment about acceleration enhancement is very important! TPSdot is a calculated variable that measures the change in acceleration (first order derivative of acceleration is called impulse if I remember my childhood teachings...). It is a very unstable value that bounces A LOT due to apparently random noise. If your threshold value on the acceleration wizard page is too low, then those bounces trigger the acceleration enhancement when you don't want it! This is one reason that my designs for the stock conversion doesn't even include the TPS. It's not used for the standard fueling algorithm. Until you are fully running you should totally disable ALL acceleration and get the VE table correct based on gentle driving. Then work with MAP based.

The Megasquirt forums are buzzing with people working on this very issue. A couple of different guys are writing code to come up with a better algorithm. Some people have been able to quiet their TPSdot values by twisting the wires going to the TPS.

Let me go look at your log....... I'm back.

TPSdot is not the problem in my opinion. Look at time mark ~32.5s in your log. Throttle is a constant 5 (how did you keep it there with no variation and RPM at 1940??) The TPSdot is a flat 0, something I rarely see! The MAPdot is ok at 19. All of a sudden, your RPMs plunge and your MAP climbs (a result of closing the butterflies and creating more manifold vacuum usually, but your TPS shows no change in the butterflies). The drop in your spark advance is probably therefore a result of the changed RPM and MAP, but I didn't check your advance table. Your AFR looks odd too, always between 10 and 10.14. VERY rich. Little correlation between AFR and pulse width.

I'll keep looking, but you definitely have something odd going on that I think has its roots in the TPS. Its value just seems wrong to me and if it is, it could be triggering faulty fueling which is bogging you. Can you swap one out? Or run without it and try. I didn't check, your are running the conventional fueling algorithm and not one of the custom ones, right?

[cineman]

You are making good progress Cineman. I will take a look at your log, but your comment about acceleration enhancement is very important! TPSdot is a calculated variable that measures the change in acceleration (first order derivative of acceleration is called impulse if I remember my childhood teachings...). It is a very unstable value that bounces A LOT due to apparently random noise. If your threshold value on the acceleration wizard page is too low, then those bounces trigger the acceleration enhancement when you don't want it! This is one reason that my designs for the stock conversion doesn't even include the TPS. It's not used for the standard fueling algorithm. Until you are fully running you should totally disable ALL acceleration and get the VE table correct based on gentle driving. Then work with MAP based.

The Megasquirt forums are buzzing with people working on this very issue. A couple of different guys are writing code to come up with a better algorithm. Some people have been able to quiet their TPSdot values by twisting the wires going to the TPS.

Let me go look at your log....... I'm back.

TPSdot is not the problem in my opinion. Look at time mark ~32.5s in your log. Throttle is a constant 5 (how did you keep it there with no variation and RPM at 1940??) The TPSdot is a flat 0, something I rarely see! The MAPdot is ok at 19. All of a sudden, your RPMs plunge and your MAP climbs (a result of closing the butterflies and creating more manifold vacuum usually, but your TPS shows no change in the butterflies). The drop in your spark advance is probably therefore a result of the changed RPM and MAP, but I didn't check your advance table. Your AFR looks odd too, always between 10 and 10.14. VERY rich. Little correlation between AFR and pulse width.

I'll keep looking, but you definitely have something odd going on that I think has its roots in the TPS. Its value just seems wrong to me and if it is, it could be triggering faulty fueling which is bogging you. Can you swap one out? Or run without it and try. I didn't check, your are running the conventional fueling algorithm and not one of the custom ones, right?

good tips spittybug.
The TPS was costant at 5, simply because i was not driving around, but just free revving ! so it was easy to keep it ;)

The AFR is not to take care off, i just have an old narrow band sensor now, even not heated, so i'm not even sure it was working and giving a good measure.

BUT today late i did some test on the roads and i'm quite sure i have no more the problem: no more falling in rpm ! so quite sure it was the accell enrichment, maybe noise in the mapdot ?
Car is drivable around :) maybe even the pullup resistor for the VR sensor helped, but i would like to take it out to see really if makes different.
I did some try in modify the VE maps and timing, lowering and hearing the engine noise for pops, pinging etc and seems not bad.
About the VE maps: after all the modify i would like to start again with the starting automatic calculate VE map depending on the reqfuel parameter, how can i have it to redraw my VE map ?

[Spittybug]

About the VE maps: after all the modify i would like to start again with the starting automatic calculate VE map depending on the reqfuel parameter, how can i have it to redraw my VE map ?

I'm not sure, sorry. Try just creating a new project? Or just let the VE analyzer do it automatically?

Glad to hear that you have things running much better. That was quick!

:nana1::Headspin::partyhat:

[cineman]

A little update on my car. Little details are important for a non standard project...
The engine works, but i was rarely satisfied by the throttle response in the past time. I had a lot of "hole" or something like misfiring.
Along all this time, i changed lot of times settings, VE maps, timing, Acceleration enrichment etc...
I change also the RPM circuitry : instead of the MS VR conditiong signals, i made a new one with the LM1815 chip, wich is designed for this purpose, and suggested on the MS forum.
( like the one suggested here )
http://www.aaroncake.net/rx-7/megasquirt/BuildingAndModding.asp
But still, i had some little problems.
I just found this days that the INJECTOR DEAD TIME, wich is usually suggested to keep at 1,0ms , what not good for me. I investigated a bit on the web, and found that usually, specially for LOW impedance inj, the numer is more around 0.6 - 0.7 , and makes BIG differences in VE table and roundness of engine health.
I am now running at Dead Time 0,650ms . I had to completely retune my VE maps after this ( easy to do with Wideband and Tunerstudio pro :) ), and the maps did "smoothed" out a lot , so they are more good to see now!
And seems that this made the throttle response and linearity to went good, and no more missfiring.
I am now waiting a new alternator , new blow-off valves , spark plug and little other things for happynes.
Good for the new spring season :wave2:

[Spittybug]

Good discovery Andrea. The guys I know over here are using high impedance injectors, but it's always worth trying to see if changing the dead time has any effect if someone is experiencing issues. The amount of information on Megasquirt is huge, just like the number of variables. The problem remains in the organization and 'searchability' of that information. Our little sub forum here should help nicely.

[opethmike]

Good discovery Andrea. The guys I know over here are using high impedance injectors, but it's always worth trying to see if changing the dead time has any effect if someone is experiencing issues. The amount of information on Megasquirt is huge, just like the number of variables. The problem remains in the organization and 'searchability' of that information. Our little sub forum here should help nicely.

I couldn't agree more, Owen. There is so much information on MS out there, but it is really scattered and poorly organized. If it weren't for this sub-forum, and the helpful folks on here, I would never have been successful with my conversion.