MS conversion questions!

[BABIS]

Hello guys,

I have a couple of questions for all you guys with a good running MS conversion.
I also have an efi converted Delorean, I have a later even firing 2.8 prv engine which is very similar to the US 3.0, it shares the same air intake.
I started using the original Renix ECU and the renault wiring harness, but then I decided to try a Megasquirt 2 ECU to have full control on the map. I used an adaptor to connect the renault harness to the the Megasquirt, but now I would like to buy a Megasquirt harness to have future references to know what all the wires are (IIRC in the MS manuals there are described all the colours of the harness).
and, I would like to create 2 indipendet harness in the engine bay, one for the MS and one for all the other electrical things (otterstat, alternator, starter and so on). I would like to mantain the original wiring colours always for future references.
I still have my original engine harness. Is it possible to open it and rerouting it the engine bay? there is also the chance to redone it completely using original colours wirings from britishwirings.com, but there are more costs and efforts involved.

currently I'm having some problems to get a clear RPM signal, I read here that is quite a common problem. I'm also using this chip http://www.diyautotune.com/catalog/lm1815-chip-p-320.html

with the Renault ECU I used a 3 wires idle control valve similar to the Delorean one, but I read that they are very difficult to use with the MS so I think I will use one of the IAC valve native to the MS along with this adapter http://www.diyautotune.com/catalog/custom-idle-air-control-body-for-use-with-jeep-40l-iac-valve-p-69.html
one barb is to be connected over the throttle plate the other under the throttle plate, right?

and, is possible to have a "check engine" signal with the MS? I would like to have the "lambda" light showing if there is a faulty sensor. I'm also interested in adding an anti knock sensor..

Best regards ;)

[Spittybug]

Is it possible to open it and rerouting it the engine bay?
Too vague..... what are you asking? Unwrapping the harness is sticky, but not hard to do.


one barb is to be connected over the throttle plate the other under the throttle plate, right?
The IAC valve mounts in the hole in the end and the two threaded/barbed nipples go on hoses that need to connect on either side of the butterfly valves. I don't recall the stock throttle body having these connection points however since the stock IAC delivered air far downstream of the throttle plates. Basically one of the ports needs to receive clean air (tap the airbox or just add a small filter on one end of the hose, and the other needs to get into the manifold, either via the same hole cast in the top of the manifold where the stock IAC dumped in, or easier, into the W pipe by taking off the little plate that is bolted down. Make sure you plug the hole in the manifold - we found an American quarter is exactly the right size to glue in there.



is possible to have a "check engine" signal with the MS?
Sort of. MS can send an output signal (up to 1 amp if I recall) under a given circumstance. For example, I have mine set to activate a buzzer if my temperature goes higher than X degrees. While I was tuning the car, I used the same feature to sound the buzzer if my AFR went too high so that I could immediately tell under what driving circumstances it would happen without having to look at the tables while driving.

[BABIS]

Too vague..... what are you asking? Unwrapping the harness is sticky, but not hard to do.

yes this is what I thought, I'm planning to remove all the wires I don't need anymore and reroute the wires in use in a better way, using nylon braided sleeves..



The IAC valve mounts in the hole in the end and the two threaded/barbed nipples go on hoses that need to connect on either side of the butterfly valves. I don't recall the stock throttle body having these connection points however since the stock IAC delivered air far downstream of the throttle plates. Basically one of the ports needs to receive clean air (tap the airbox or just add a small filter on one end of the hose, and the other needs to get into the manifold, either via the same hole cast in the top of the manifold where the stock IAC dumped in, or easier, into the W pipe by taking off the little plate that is bolted down. Make sure you plug the hole in the manifold - we found an American quarter is exactly the right size to glue in there.


I will use 3.0 throttle body and manifold, and I need to do a couple of weldings so the IAC will be placed accordingly..



Sort of. MS can send an output signal (up to 1 amp if I recall) under a given circumstance. For example, I have mine set to activate a buzzer if my temperature goes higher than X degrees. While I was tuning the car, I used the same feature to sound the buzzer if my AFR went too high so that I could immediately tell under what driving circumstances it would happen without having to look at the tables while driving.

nice to know!

[Bitsyncmaster]

The OEM harness the wires are pretty brittle from the insulation age. You would probably want to shorten or lengthen the wires anyway. Just make up your own document with new colors if you don't buy the original color wire.

[BABIS]

The OEM harness the wires are pretty brittle from the insulation age. You would probably want to shorten or lengthen the wires anyway. Just make up your own document with new colors if you don't buy the original color wire.

Thanks for the thoughts Dave, I just want to keep original colours for future references...

[AdmiralSenn]

Regarding the RPM noise, where are you getting your RPM input from? I had endless problems with noise until I switched to the wires from the distributor's internal VR sensor, spliced from within the car behind the driver's seat. I also have a shielded coil-to-distributor cap wire but I don't know if it really helped.

You're on the right track with the VR circuit, maybe before anything else you should try adjusting the VR potentiometers on the MS mainboard?

[BABIS]

and, is possible to have a "check engine" signal with the MS?

MS can send an output signal (up to 1 amp if I recall) under a given circumstance. For example, I have mine set to activate a buzzer if my temperature goes higher than X degrees. While I was tuning the car, I used the same feature to sound the buzzer if my AFR went too high so that I could immediately tell under what driving circumstances it would happen without having to look at the tables while driving.


I found this interesting article about the "check engine light" but I guess this is feasible only with the MS3, or not? http://www.msextra.com/doc/ms3/cel.html

[Spittybug]

Nice feature. I'm running MS2e, not MS3. Looks like they just continue to improve things. One day I'll get a MS3 box and keep the MS2 as a spare..............too many other projects to worry about it now though.

[BABIS]

Regarding the RPM noise, where are you getting your RPM input from?
You're on the right track with the VR circuit, maybe before anything else you should try adjusting the VR potentiometers on the MS mainboard?

I will check the RPM input.

anyway, maybe this will help? http://www.diyautotune.com/catalog/zeal-engineering-daughterboard-with-dual-vr-conditioners-p-378.html

[BABIS]

Hi guys!

I have a bunch of new questions for you. As I said before I am converting my previous efi setup (original Renault renix) to the Megasquirt and I am planning the various stages of this conversion.

I’ve read almost every efi thread from this forum and I found some interesting subjects to talk about.

1) I’m replacing the clt and iat sensors with the ones MS specific. I have a couple of ideas about the clt sensor placing: I have a new Y pipe without threads (it’s not the delorean one, it’s from an earlier prv) and I can tap it for the 3/8” sensor, or I can buy a M18 to 3/8” adaptor to be placed on the thermotime switch hole in the wp ; what do you think is the best place?

2) I know that for a good working efi it’s all about good power sources and good grounds; I’m gonna follow this wiring scheme http://www.msextra.com/doc/general/pix/ms2v3-external.png . about the various sensors: in this scheme there is written that pins 1,2,7,19 are all good for sensor grounding (iat, clt, tps, crank) ; should I ground them all on the same pin or should I deserve one ground pin for each sensors?

3) I’ve read that the best thing to do is to feed the ecu and the injectors and the fuel pump with separate power sources (directly from battery) and dedicated relays; I will use a Innovate LC-2 and I’ve read that it needs a switched power source, do you think it’s worth to wire it up a dedicated relay like described here? http://www.innovatemotorsports.com/support/manual/LC-2_Manual.pdf the LC-2 ground should be connected to a MS pin ground or to the main grounding point?

4) Do you think I should wire the MS grounds (and other grounds..) directly to the battery or I can wire them on a good spot of the frame? I will install also Hervey double ground wires.. I guess I will wire there also the coil module ground.

5) LC-2 gauge: http://www.innovatemotorsports.com/support/manual/G2_G4_G5_Gauge_Manual%28B%29.pdf
I guess I can wire it in the same ground of the LC-2 and the same switched source. About the signal wires from the LC-2, the gauge only works with a wide band signal but I want to use the wide band signal for the ecu. Is it possible to reprogram both the signal from the LC-2 to be wide band?

6) I will use this knock sensor module http://www.viatrack.ca/KnockMS/KnockMS.PDF but I didn’t understand if it must be wired on a switched source or just from the battery (fused?). I guess the ground will go to the main grounding point (battery)


Thanks in advance!

[Citizen]

I wonder now just how many DeLoreans have been converted to MegaSquirt, let alone EFI. I was trying to track EFI conversions, but now maybe I need to track MS as well.

Thomas

...

[Spittybug]

See inline responses.


Hi guys!

I have a bunch of new questions for you. As I said before I am converting my previous efi setup (original Renault renix) to the Megasquirt and I am planning the various stages of this conversion.

I’ve read almost every efi thread from this forum and I found some interesting subjects to talk about.

1) I’m replacing the clt and iat sensors with the ones MS specific. I have a couple of ideas about the clt sensor placing: I have a new Y pipe without threads (it’s not the delorean one, it’s from an earlier prv) and I can tap it for the 3/8” sensor, or I can buy a M18 to 3/8” adaptor to be placed on the thermotime switch hole in the wp ; what do you think is the best place?

Shouldn't make an ounce of difference.

2) I know that for a good working efi it’s all about good power sources and good grounds; I’m gonna follow this wiring scheme http://www.msextra.com/doc/general/pix/ms2v3-external.png . about the various sensors: in this scheme there is written that pins 1,2,7,19 are all good for sensor grounding (iat, clt, tps, crank) ; should I ground them all on the same pin or should I deserve one ground pin for each sensors?

Common the EFI grounds and make sure that they are all well connected to a single grounding site on the block. Separating them causes issues.

3) I’ve read that the best thing to do is to feed the ecu and the injectors and the fuel pump with separate power sources (directly from battery) and dedicated relays; I will use a Innovate LC-2 and I’ve read that it needs a switched power source, do you think it’s worth to wire it up a dedicated relay like described here? http://www.innovatemotorsports.com/support/manual/LC-2_Manual.pdf the LC-2 ground should be connected to a MS pin ground or to the main grounding point?

ALL grounds to the same point. I have my LC-2 on it's own relay IIRC.

4) Do you think I should wire the MS grounds (and other grounds..) directly to the battery or I can wire them on a good spot of the frame? I will install also Hervey double ground wires.. I guess I will wire there also the coil module ground.

Mine go to a good bolt in the block. I added another grounding strap from battery to transmission just for giggles.

5) LC-2 gauge: http://www.innovatemotorsports.com/support/manual/G2_G4_G5_Gauge_Manual%28B%29.pdf
I guess I can wire it in the same ground of the LC-2 and the same switched source. About the signal wires from the LC-2, the gauge only works with a wide band signal but I want to use the wide band signal for the ecu. Is it possible to reprogram both the signal from the LC-2 to be wide band?

I don't use a gauge, sorry. No need. If you want, set an alarm using the output circuits of your MS. Connect a buzzer and set it to go off if you exceed a certain AFR.

6) I will use this knock sensor module http://www.viatrack.ca/KnockMS/KnockMS.PDF but I didn’t understand if it must be wired on a switched source or just from the battery (fused?). I guess the ground will go to the main grounding point (battery)

I don't have a knock sensor. Always fuse ANY circuit. Ground it to the same place as ALL MS GROUNDS.

Thanks in advance!

[Josh]

Here are my responses, for what it is worth...


Hi guys!

I have a bunch of new questions for you. As I said before I am converting my previous efi setup (original Renault renix) to the Megasquirt and I am planning the various stages of this conversion.

I’ve read almost every efi thread from this forum and I found some interesting subjects to talk about.

1) I’m replacing the clt and iat sensors with the ones MS specific. I have a couple of ideas about the clt sensor placing: I have a new Y pipe without threads (it’s not the delorean one, it’s from an earlier prv) and I can tap it for the 3/8” sensor, or I can buy a M18 to 3/8” adaptor to be placed on the thermotime switch hole in the wp ; what do you think is the best place?

You can place the sensor anywhere you want. I placed mine in the thermostat housing (3.0). It used a m14 thread so I used a 1/4 to 1/8 npt bushing and screwed in my Saturn clt. It uses the same gm sensor values but in a small 1/8" npt package.

2) I know that for a good working efi it’s all about good power sources and good grounds; I’m gonna follow this wiring scheme http://www.msextra.com/doc/general/pix/ms2v3-external.png . about the various sensors: in this scheme there is written that pins 1,2,7,19 are all good for sensor grounding (iat, clt, tps, crank) ; should I ground them all on the same pin or should I deserve one ground pin for each sensors?

I wired off of this diagram http://www.megamanual.com/ms2/v3ext_wiring.gif

So ground pins 8,9,10,11, and 18 directly to the block. I used the rear passenger side lifting lug. You can gather these wires to a thicker wire. I understand the ground vary from the ones on the other diagram but most of the pins 1-19 are ground. All my sensors are grounded to the ms box as specified on pin 19. DO NOT GROUND SENSORS DIRECTLY TO THE BLOCK.

3) I’ve read that the best thing to do is to feed the ecu and the injectors and the fuel pump with separate power sources (directly from battery) and dedicated relays; I will use a Innovate LC-2 and I’ve read that it needs a switched power source, do you think it’s worth to wire it up a dedicated relay like described here? http://www.innovatemotorsports.com/support/manual/LC-2_Manual.pdf the LC-2 ground should be connected to a MS pin ground or to the main grounding point?

Ground the wideband controller directly to the block, the same place where you grounded the MS grounds.

As for my fuse setup:
o2 and fuel pump each have a fuse, but powered off the same relay controlled by the fuel pump MS pin.
each injector bank has its own fuse, both powered off a relay to a key on switched source. The MS box is also fed by this relay with its own fuse.

So two relays and individual fuses for each device.


4) Do you think I should wire the MS grounds (and other grounds..) directly to the battery or I can wire them on a good spot of the frame? I will install also Hervey double ground wires.. I guess I will wire there also the coil module ground.

As mentioned, wire them directly to the block/head. Also check the ground strap on the motor mount and ensure it is in good working order.

5) LC-2 gauge: http://www.innovatemotorsports.com/support/manual/G2_G4_G5_Gauge_Manual%28B%29.pdf
I guess I can wire it in the same ground of the LC-2 and the same switched source. About the signal wires from the LC-2, the gauge only works with a wide band signal but I want to use the wide band signal for the ecu. Is it possible to reprogram both the signal from the LC-2 to be wide band?

The LC2 has two outputs (yellow and brown wire IIRC). One is wideband and one is narrow. however, you can used the included serial cable and supplied software and recalibrate the controller to output a wideband signal to both. You can now use one wire for the MS and one for the gauge. Do not wire the gauge and MS to the same wire.


6) I will use this knock sensor module http://www.viatrack.ca/KnockMS/KnockMS.PDF but I didn’t understand if it must be wired on a switched source or just from the battery (fused?). I guess the ground will go to the main grounding point (battery)

Is there a reason why you want a knock sensor? It will add alot of work when tuning and make tuning more difficult. PRVs are very low compression, detonation isn't really a big deal. I was running 16.5 afr on the highway and I wasn't close to concerned with knock sensing.


Thanks in advance!

[BABIS]

Hi guys, I have some news to share with you. I finally (almost) completed the internal wirings for the EFI set-up.

the wirings arrangement can be seen in this pdf 36354

I have wired 3 relays: LC-2, MS and injectors, fuel pump. all the wires are fused through this useful fuse box which give me +12V, +12V on key and a common ground: http://www.ripca.com/nl_en/fuses-holders-relays/fuses-holders/fuse-boxes/standaard-steekzekeringhouder-voor-12-zekeringen.html

I will try to explain each circuits, and I have a couple of questions for you.

I found a male plug for the rpm relay socket from which I use the green wire from fuse 1 to feed the "+12V on key" fuse box side, brown wire from fuse 7 to feed the fuel pump relay, white/purple wire to feed the fuel pump and white slate wire for the tach signal to the MS. http://imagizer.imageshack.us/v2/800x600q90/540/aFrduO.jpg
Since fuse 7 has 2 different wire gauges from factory I routed a new 12AWG brown wire from the fuse to the the rpm relay socket, as the original lambda relay is not needed.
I routed a new white/purple wire from the relay to the rpm socket but I found the white/purple wire only in 14AWG: do you think it will be a problem?
should I change the amperage of fuse 7? now it feeds just the fuel pump, maybe a 15amp fuse would be enough. the 10amp fuse for fuse 1 sounds appropriate.
I am wondering also about the fuse amperage to pin 86, 1amp should be adequate.

about the "main relay", it is feeded by a 20amp fuse from the "+12V" side of the fuse box. maybe I can reduce fuse amperage to 15amp. the relay's 87 pin goes to another fuse box (this one http://www.ripca.com/nl_en/fuses-holders-relays/fuses-holders/fuse-boxes/6-polige-zekeringkast-met-deksel.html) which feeds the MS, both injectors banks and the knocksense module (this one will have a 1amp fuse since it draws 10 mA). all the wires used are 14AWG.

the LC-2 relay is wired as per the instructions in the manual at page 4 http://www.innovatemotorsports.com/support/manual/LC-2_Manual.pdf

likewise the AFR gauge is wired as per these instructions http://www.innovatemotorsports.com/support/manual/G2_G4_G5_Gauge_Manual%28B%29.pdf
the white wire needs to be connected to a dash light wire, I think I'm gonna wire it to the red/orange - red/brown wire at the A/C panel relay (I connected them as per the A/C light mod) http://imagizer.imageshack.us/v2/800x600q90/673/uNU2Q6.jpg

lastly, I have the fuse box main ground and +12V connected to the ground and +12V spot on the firewall (driver side) but possibly I'd like to connect them directly to the battery but it seems that the battery compartment is sealed and there is no way to route the wires to the upper electrical tray (unless I am missing a free spot). so I should have to drill the "upper closing panel" or (mad idea) to route both wires outside of the cabin from the battery wires grommets and reintroduce them through the parking cables grommets..

Let me what you think about all this stuff!
Many thanks ;)

[Bitsyncmaster]

You really overkill the wiring with that heavy gauge wire on signal lines but that's not a bad thing if you already have the wire in stock. I pretty much us 16 AWG wire because that is what I have and it fits most all of the crimp terminals. If I need a large current circuit I can double up on the wire.

Fuses......As you probably have seen, I've been running testing on fuses. The rating of a fuse is what it can carry for current without blowing open. Fuses are not really a device to protect electronics from to much load since fuses can take hours to blow open running a little over the rated current. Fuses do protect your wiring from short circuits very nicely since they blow open quickly then the currents are at least two times the rated currents. Just remember using lower current ratings, the fuse resistance (voltage drop) goes up with lower current ratings. So your fuse will produce more heat if that's something your concerned about.

[BABIS]

Hello guys,

just a quick question, what should I do with the "metal sleeve" from the MS screened cable (with pin cables #1, 24, 26) ? http://www.diyautotune.com/images/msharness/mswiring.png

I am using a VR sensor which has 2 cables, and I don't know if I should leave the metal sleeve (pin #2) as it is, ground it to the block or crimp it with the VR ground wire..

Cheers

[Bitsyncmaster]

Hello guys,

just a quick question, what should I do with the "metal sleeve" from the MS screened cable (with pin cables #1, 24, 26) ? http://www.diyautotune.com/images/msharness/mswiring.png

I am using a VR sensor which has 2 cables, and I don't know if I should leave the metal sleeve (pin #2) as it is, ground it to the block or crimp it with the VR ground wire..

Cheers

Shielded wire should only have one end of the shield grounded. That is to prevent any current flowing through the shield which reduces the effect to shield from external noise on the wires.

[BABIS]

Shielded wire should only have one end of the shield grounded.

the "shield" goes to the MS connector (and so to the ECU), pin #2 on this wiring scheme: http://www.diyautotune.com/images/msharness/mswiring.png

[dn010]

I don't remember what pin was used since I have a relay board but the shield was grounded to the MS via that board. The shield ended a few inches short of the connector to the sensor on the other end. Keep in mind to run your shielded wire away from any high current wiring such as sparkplug wires etc and watch for sharp bends/edges. I ran my shielded wire separate and away from any other wiring, it also enters the car from the engine compartment separately from the rest of the wiring.

Edit: After looking at the MS3X/3.57 manual, it appears my VR sensor wire's shield is wired to Pin #1-2 of the MS ECU. Also page #70 of that manual shows a small diagram and says to use sensor ground to ground the shield of the shielded wire. Check that page out for more info.