S52 OBD1 cranks but won't start

[hammslice]

Well, I have been working on this swap for quite some time now and I'd like to say thanks to everyone so far, because this is only the second time I have had to post a question. Search has provided very many answers.

Turned the key for the first time just recently and the motor just cranks and cranks and won't fire.

Things I have checked so far:

I know my fuel pump relay is bad, I jumped it and it powered up but the motor still won't start.
I went back and checked this relay by hooking 12V to 30 and 85 and grounded 86 then put my test light on 87. It clicked and the light illuminated, so the relay is good.

My DME (Red Label 413) is getting power because my ICV hums and the Check Engine light illuminates.

I know my camshaft sensor is not swapped with the crankshaft sensor on the harness. I triple checked the wire colors before installing the harness and just checked the wires again now that it's all installed. (Ref. Post #52 for notes)

I am using the M44 crank sensor (12-14-1-247-62) in the stock S52 location per the advice I got in the only other question I asked. http://www.r3vlimited.com/board/showthread.php?t=185778 This is the only sensor I bought new so it should be good.

I'm not sure if I am getting spark, I suspect no, but I'm not sure why or how to know for sure.

Where should I look?

Any help is very appreciated. TIA.

Edit: IT STARTED! page 6 post 85 for video. Had to bypass E30 code immobilizer circuit.

[325islovE]

is the fuel pump relay bad, or is it that the fuel pump that isnt pumping when you jump the pins? If your fuel pump works, check RESISTANCE between pin 16 and 43 at the ecu harness or pins 1 and 2 on the CPS(its the same thing). Should be around 550ohms, bently says 1200ohms but ive never seen that much resistance there.

other things to look for is physical damage in the dme, just because you hear one thing working doesnt mean another circuit isnt fucked up, backwards chip, or a mixed up wire in the wire harness.

[hammslice]

I had the pump running when I jumped terminals 30 and 87.

Resistance reads 570 ohms on crank sensor.

I think the Chip is installed correctly based on how the label is from TRM. Is that safe to assume? The Dinan chip that was in the ECU when I got it had the writing in the same orientation.

[samiam3356]

Just went through this this week. Just because it doesn't crank when you jump the fuel pump doesn't mean the relay is bad. The bentley says the CPS resistance should be around 1280~10. Checked mine and it was in the low 500's. Ordered a new one and it read exactly the same thing. Still used the new one(they replaced it for free) when I put it all back together last night. I think my issue was vacuum leak on the ICV and stupid plug that goes into the manifold.

I basically pulled off the tab on that plug and used a few zip ties to keep it snug.


Also made sure all the vacuum lines were secure and clamped down good.

Got in it this morning and it fired right up and idled better than ever.


How do you have your vacuum lines ran? Everything for sure the right way?

[Philo]

Did you make or buy the wiring harness?

[hammslice]

i started with an e36 harness and cut the x20 off and converted it to a c101 by looking up and verifying ever wire in the ETM on both sides (body/engine) and using this method: http://www.r3vlimited.com/board/showthread.php?t=200776

IIRC I did have to make an educated guess regarding ABS power, but I don't think I ran into any other snags doing it.

[Philo]

Was the harness from an automatic or a manual car? If it was from an auto car, you need to loop the red wire with the white stripe on it. That wire tells the ECU that the car is in park, and triggers the fuel pump to run.

[hammslice]

its a manual harness.



I guess tomorrow I will double check the connections at the c101.

[hammslice]

small vac line from PCV to underside of manifold
large vac line from PCV to intake boot
underside of manifold to ICV to intake boot
small vac line from FPR to nipple towards back of manifold
line from throttle body to check valve to charcoal canister

[HakenTT]

I think the Chip is installed correctly based on how the label is from TRM. Is that safe to assume? The Dinan chip that was in the ECU when I got it had the writing in the same orientation.

chip looks installed correctly, but never go with orentation of the sticker but by matching a notch on the socket with notch on the chip.

[hammslice]

fuel pump relay is good, i did a sanity check on it (see OP) and found it to be working. I also pulled back the boots on my c101 connector and didn't see anything wrong except a bad crimp on coolant temp. i replaced the pin.

Anybody near Fort Walton Beach, FL have an extra DME? Or want to lend some brain power? I have beer.

[hammslice]

I checked the DME relay and the O2 sensor relay in the same fashion and they are also working.

[MattM]

fuel rail hooked up backwards?

[hammslice]

they are hooked up correctly.

[samiam3356]

Bottom is return I thought, and it looks like its headed to the front of the motor. I would have to look at min to be sure. The return is the back of the motor just to be clear