Won't run without CPR(WUR) and CSI plug swapped

[elfking]

So I have been trying to tackle a few fuel issues as of late, and I got it all back together today...

It won't run without having the WUR and CSI plug swapped, and when when its running, if I remove the plug off the CSI the car will die.

With the plugs in the proper order the car will start for half a second or two then die and will just crank over until I swap the WUR and CSI plugs.

I have replaced the thermotime switch with one from DMCH, which I believe to be working. However based on the symptoms I guess I need test this and verify that it is working correctly.

When I did get it started with the plug swap it does seem to be running very rich, or at least smells rich. (which from what I read happens because it keeps this CIS firing all the time when its swapped)

Anyone have any thoughts on something I may be missing here?

I did some recent work and since then it has this behavior...
Recent work is:
1. Had the Fuel Distributor Rebuilt.
2. Replaced the fuel lines with the braided steel lines from special t auto.

Maybe I knocked something loose, but I haven't figured it out yet...

When you have the engine Cranking over should I be hearing the fuel pump running? I hear it when key is in ON position but I do not hear it when its cranking over trying to start.

[DMCMW Dave]

After changing the FD did you adjust the CO? Sounds like that is set way too lean, or there is something wrong with the FD.

When you have the plugs swapped you are running entirely on the cold start injector, which will be very rich on some cylinders and not on others. You'd probably find that it won't do much faster than a fast idle as there is only one fuel flow rate.

Also - doublecheck the fuel line connections to the FD.

[elfking]

Thanks for the quick reply, I'd there a way to set a 'base' setting for the CO ? I fear I may have got that a bit out of hand.

I'll triple check the lines but I checked twice today and it seemed like I had them right. I used a PDF I found on one of the forums which was a great reference diagram.

Also which direction on the screw makes it more rich?

Thanks for the help!

[jmpdmc]

Also which direction on the screw makes it more rich?

Right to richen, left to lean.


Jeff

[opethmike]

Thanks for the quick reply, I'd there a way to set a 'base' setting for the CO ? I fear I may have got that a bit out of hand.


Place the six injectors into containers (empty six pack of Corona comes in handy)
Jumper the RPM relay to run the fuel pump continuously
Enrich the mixture until the injectors JUST start to drip, then lean it out JUST enough to make them stop

[Bitsyncmaster]

Place the six injectors into containers (empty six pack of Corona comes in handy)
Jumper the RPM relay to run the fuel pump continuously
Enrich the mixture until the injectors JUST start to drip, then lean it out JUST enough to make them stop

I like your very basic how to set the mixture as a baseline. We should keep it in the how to folder.

[elfking]

Right to richen, left to lean.
Pefect thanks!

Jeff


Place the six injectors into containers (empty six pack of Corona comes in handy)
Jumper the RPM relay to run the fuel pump continuously
Enrich the mixture until the injectors JUST start to drip, then lean it out JUST enough to make them stop

I really had a bit of trouble pulling the back left injector, so I pulled the easier ones to get at and took a look, made them do exactly as you described.. Turned it until they were dripping.. backed it off a tiny bit at a time until they stopped dripping.

Put them back in and it fired right up!


I like your very basic how to set the mixture as a baseline. We should keep it in the how to folder.

It really did work great to get me at least up and running. Now I just have a high idle to deal with... It was sitting about 1k which is where it was before I did all this, then I warmed it up some more and drove it around a block or two and it then wanted to sit at 1500RPM, so I guess something is still a bit off.

[opethmike]

Thanks guys, but the credit goes to Dave Swingle, as I learned the trick from him.

There are a couple of things that can cause a high idle. My personal experience for a high idle was a mis-adjusted throttle stop screw for the idle microswitch. I lowered it half of a turn, and was back down to the ~900 RPM I like. That may or may not be your issue.

[Bitsyncmaster]

Now I just have a high idle to deal with... It was sitting about 1k which is where it was before I did all this, then I warmed it up some more and drove it around a block or two and it then wanted to sit at 1500RPM, so I guess something is still a bit off.

A bunch of things can prevent the idle system from holding 775 RPM (closed loop).

1) Vacuum leaks. These increase the idle RPM and when the idle motor is fully closed you have lost closed loop idle.

2) Ignition advance is on. This is the same problem, increases idle speed past the point the idle system can work. The idle switch not adjusted or working will cause this. As will the connector is off of the advance solenoid.

3) Curb idle adjusted to high. That is the lower screw on the throttle arm. Same problem.

4) Air bypass screws not closed. Those three brass adjustments must be closed.

Of course a failed idle ECU and or idle motor will cause it.

[opethmike]

Oh, since you have the car running, you can now get a fine tune of the idle mixture set. Do you have a multimeter with a dwell meter on it?

If you do, plug it into the diagnostic port (plastic thing behind the driver's side cylinder head). Then, once the car is warmed up, you should see the reading fluctuating. You want to set it so that the average of the reading is 45.

There is a pdf attached to a message on another forum that describes the process in better detail:

http://www.dmcplace.com/showthread.php?tid=18&pid=37#pid37

[Farrar]

There is a pdf attached to a message on another forum that describes the process in better detail:

Ooh, another DMC forum! Sweet!

:D

Farrar

[outatym2001]

I set up an account on that other DeLorean site just so I can get my own copy of the DMC Dwell pdf file.
I would give some credit to the original maker of the pdf file but I don't see their name anywhere.
So here you go. I copied it so everyone can get theirs.

[sean]

Another fine tangent by Bill has been moved here: http://dmctalk.org/showthread.php?504-Bill-is-not-Sam....That-is-all. Feel free to not post to it as it is pretty much worthless.

[elfking]

Thanks for the tips everyone... I'll keep taking s crack at it to see if I can get the idle down.

Unfortunately I do not have a dwell meter.. Only a multimeter. Does anyone recommend a brand/model over another? I'm not opposed to getting the right tools for the job.

[Bitsyncmaster]

Thanks for the tips everyone... I'll keep taking s crack at it to see if I can get the idle down.

Unfortunately I do not have a dwell meter.. Only a multimeter. Does anyone recommend a brand/model over another? I'm not opposed to getting the right tools for the job.

I think Sears still sells one. You need one that can real dwell with 4 cylinder mode. Or one that reads duty cycle. I have a Snap-ON meter that does both. Some multimeters will work. Look for duty cycle or a "%" range on the multimeters. My multimeter has "%" and it is a EXTECH 570, but that meter is pricey.

[opethmike]

Thanks for the tips everyone... I'll keep taking s crack at it to see if I can get the idle down.

Unfortunately I do not have a dwell meter.. Only a multimeter. Does anyone recommend a brand/model over another? I'm not opposed to getting the right tools for the job.

This is the exact one I have, and I am very satisfied with it:

http://www.amazon.com/Actron-CP7677-Automotive-TroubleShooter-Multimeter/dp/B0002LZU7K/ref=sr_1_2?ie=UTF8&qid=1308750805&sr=8-2

[elfking]

1408

I don't think my little craftsman is up to the job...

Maybe I'll pickup that one from Amazon. With the directions on the PDF it says to have it at about 45 degrees... But this one looks digital so what numbers am I looking for??

Thanks again

[opethmike]

Still 45; the numbers will just be displayed on the digital display, instead of a needle swinging on an analog gauge.

Keep in mind that 45 will be the average you are looking to achieve. Once the car has warmed up, the reading will constantly fluctuate.

[Bitsyncmaster]

I think you want less then 45 deg. From what I remember it's more like 30 deg. But as opethmike said the numbers will be swinging around that number so you have to look for an average.

If using duty cycle the numbers are about 10% higher then reading dwell in degrees.

[82DMC12]

I think you want less then 45 deg. From what I remember it's more like 30 deg. But as opethmike said the numbers will be swinging around that number so you have to look for an average.

If using duty cycle the numbers are about 10% higher then reading dwell in degrees.

I just went though this a couple weeks ago.

My advice is don't get hung up on the numbers or the scales. On the analog meter, you want the needle pointing straight up and down like to 12-oclock as your 50% duty cycle reading. You want the needle, when the engine is hot, to be sweeping just as much to the left of 12 oclock as you want it to the right of 12 oclock. You cannot check this when the engine is cold or warming up because the Lambda system is in a fixed value mode until the O2 sensor is hot.

***If the FV is running at a 50% duty cycle, that means the exhaust is neither rich nor lean. That's the key.

***If the needle is swinging further to the left, that means the duty cycle is less than 50%, the system is too RICH, so the FV is opening LESS OFTEN in an attempt to lean-out the mixture. You will need to turn the screw to LEAN OUT the mixture and bring the needle closer to 50%.

***OPPOSITE CASE! The needle is swinging too far to the right. Duty cycle is greater than 50%, FV is opening longer than normal in an attempt to enrich the mixture. This is a LEAN condition. You must turn the screw to RICHEN the mixture.

I hope that makes sense! Basically you want the needle to be swinging back and forth with an average of 12 oclock. This is a very visual thing to do, and I think an analog meter would work a lot better than a digital one.

I bought a cheapie analog one at Autozone a few years ago. Not sure if they still have them.

Also, make sure you make only one or two adjustments, then drive the car around the block kind of hard, then park and check again. This will keep the plugs from fouling out and messing up the readings. Once you think you have it perfect, drive around, and check again. If it's still perfect you are in good shape, and probably running better than a lot of other D's out there!

Andy

Andy

[Bitsyncmaster]

The way I see it is you hold the WOT switch in and take a reading. That sets duty cycle at 60%. I think that would read 54 degrees with a 4 cyl dwell. This checks that your meter is working correctly and your WOT switch is working.

When the engine is warming up it runs a preset 50% which holds the engine a little on the rich side.

Now with your warmed up engine you want to set the duty cycle in the middle of that WOT reading. Hence about 30%. So you definitely should be setting less than 50% so you get a rich mixture while your engine is warming up and your WOT is running an even richer mixture.

[82DMC12]

The way I see it is you hold the WOT switch in and take a reading. That sets duty cycle at 60%. I think that would read 54 degrees with a 4 cyl dwell. This checks that your meter is working correctly and your WOT switch is working.

When the engine is warming up it runs a preset 50% which holds the engine a little on the rich side.

Now with your warmed up engine you want to set the duty cycle in the middle of that WOT reading. Hence about 30%. So you definitely should be setting less than 50% so you get a rich mixture while your engine is warming up and your WOT is running an even richer mixture.

Dave,

I think you are getting degrees and percents mixed up. Yes, the WOT switch will bring the needle to a steady reading above 50% (12 o-clock). I think it's about 60%. Also, if you were to unplug the lambda thermal switch and short it to ground, you will simulate a cold engine. This will also read 60%, which as you said will signal a rich condition. This is open-loop cold mode.

When the thermal switch warms up, it signals a warm engine, but if the O2 sensor is not sending a good signal yet, it will still be in an open loop (warm) mode. This will bring the needle to 50% steady reading. No swinging.

Once the O2 sensor gives a good reading, the needle will start to swing left and right, and it should go to the left of 12'clock the same distance it goes to the right of 12'clock. The average of the swing should be straight up and down.

When reading it this way, you don't have to care about the dwell numbers or the scales or anything like that. Anyway, if you insist on using the dwell, it will go from about 38 to 52 on the 4 cyl scale. The rich 60% fixed settings are about 54 on the 4 cyl scale.

Another test you can do is to remove the wire from the O2 sensor, temporarily attach a longer wire to it, and ground the wire to the engine block while reading the dwell meter. This will make the meter read about 95% cycle, or a super-lean condition. Then take a 1.5V battery and put that between the wire and the engine block and ground the battery to the motor. That will show a 10% duty cycle, or super-rich condition. This way you can test your Lambda module to make sure it will accept and react to extreme readings.

Thanks to Dave Swingle for the above test, which I have verified with Probst's Bosch FI manual.

Andy

[Bitsyncmaster]

Your correct Andy with your description of how it works. But not all meters will read at a 12:00 position. Also I don't think the thermal time switch is the temperature sensing element into the lambda ECU. There is another thermal switch that I think is in the VOD.

[82DMC12]

Your correct Andy with your description of how it works. But not all meters will read at a 12:00 position. Also I don't think the thermal time switch is the temperature sensing element into the lambda ECU. There is another thermal switch that I think is in the VOD.

Oops you are right. I always get those names mixed around! Thermotime switch is what turns the cold start valve on/off. The switch I'm talking about is actually called the Lambda Thermal Switch and is in the VOD - pass side of the Y-pipe, towards the front of the car. I had to look up the 'official' name of it in the shop book....

Thanks Dave :-)

Andy

[82DMC12]

By the way, if anyone wants to see the couple of pages in the Probst book dealing with dwell meter tests, let me know and I can scan and email them to you. I'm not sure if I should post them on here because it is copyrighted. I highly recommend buying the book, you can find it on Amazon here:

http://www.amazon.com/Bosch-Fuel-Injection-Engine-Management/dp/0837603005/ref=sr_1_1?ie=UTF8&qid=1308782153&sr=8-1

Between this and the shop manual, which I think is pretty good all-in-all, K-Jet should not be a mystery.

Andy

[elfking]

Alright so I finally got around to trying to set the mixture with a dwell meter and either I am too stupid to figure out which settings / buttons give me the right numbers to read or something is off...

2727
http://tapatalk.com/mu/43bcca03-426f-ea1d.jpg

I borrowed this meter... Put the positive pin into the #3 on the diagnostic plug which said it was for the o2 sensor...

The only readings I could get were the voltages from the o2. Nothing in that 45-50 degree range that you all were talking about... Maybe I need to buy that meter that was suggested... I just thought this one might have it as I saw the duty% and range buttons....

My idle when warm seems to want to sit at 12-1300 range and pretty constant so maybe I won't get a reading without bringing high idle down first?

I tried a quarter turn left or right from where the mixture screw sits now and the car tries to die... Hmmm

Any tips would be most appreciated!

[Bitsyncmaster]

Alright so I finally got around to trying to set the mixture with a dwell meter and either I am too stupid to figure out which settings / buttons give me the right numbers to read or something is off...

2727
http://tapatalk.com/mu/43bcca03-426f-ea1d.jpg

I borrowed this meter... Put the positive pin into the #3 on the diagnostic plug which said it was for the o2 sensor...

The only readings I could get were the voltages from the o2. Nothing in that 45-50 degree range that you all were talking about... Maybe I need to buy that meter that was suggested... I just thought this one might have it as I saw the duty% and range buttons....

My idle when warm seems to want to sit at 12-1300 range and pretty constant so maybe I won't get a reading without bringing high idle down first?

I tried a quarter turn left or right from where the mixture screw sits now and the car tries to die... Hmmm

Any tips would be most appreciated!

Looks like that meter should work with the "% DUTY" blue button. I would guess you need to have the switch on the "RPM" range. You want the "+" lead on the orange wire on the diagnostic port. You can also get at that wire on a two pin connector in the harness at the back of the engine compartment. The black wire "-" from the meter attachés to the engine block where there is no paint.

Your meter should probably read 0.00% when the engine is not running so play with the meter settings until you see that. Try setting the rotary switch to RPM, then press "range", then press %Duty.

[elfking]

Alright so after all that time, I managed to get the dwell dialed in and got it running so well that I took it down and it passed the rolling dyno smog test in the area first try.. no funny business! So its nice and registered now!

The dwell issue not reading I was having... it was on the correct settings before, it was just so too rich, I had to lean it out, it would make the car stumble and sound like it was going to die for a few. Then it would catch and I saw the numbers come alive.. so I guess it was so rich that it wasn't even trying before giving me that 12-13 reading that I thought was just the voltage.

I had set it so it was fluctuating between 20's and 40's and I was shocked at how well it did on the smog dyno.

As for my lovely fuel distributor... It was leaking again from when I got it back from the rebuild. So I tore it down myself, found a pinched/damaged o-ring off the plunger barrel ( I think its called) so I found a replacement locally and put it back together... and so far so good no leaks.

I took a whole bunch of pictures of my fuel distributor torn down, not sure if anyone would care to have them for reference pictures.. But I think I will post them up here just in case someone wants to see, I found it interesting at least!

3036

Thanks again to everyone for the help. I do very much appreciate it...

Onto the next tasks!

[elfking]

I didn't tear the fuel Distributor all the way down since I found my problem pretty quickly I just was in a mindset to get the car on the road and hoped the rest was done right.

Enjoy!

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