90 Sunbird, turns over but won't start, ***Help***

[toofast4u9100]

Hello! I am working on a 90 Sunbird 2.0L that's driving me crazy... here's the situation: 12 degrees outside and the car won't start. Sun came out, outside temp rose, tried it and it started. Drove car to work, drove car home no problems. Later, that night, car wouldn't and hasn't started since. Turn ignition key on, no check engine light, no fuel pump prime (prime function never worked since bought the car), Turn engine over, (still no check engine light) fuel pump kicks on, injector doesn't pulse, but I do have gas to it. If I dump gas in TBI, car will start, I even kept it running for 30 seconds by trickling gas in the TBI.

I hooked up a SnapOn Scanner to the ALDL and it tells me no communication with ECM. I checked ground at ALDL (A terminal) and it was good, but I don't have the 5 volts coming to B or to M.

Here's what I did so far: checked all fuses, good.
I installed new fuel pump relay. New fuel filter. Still no prime function but works when engine cranks.

Checked for power to injector, good.

I unplugged both connectors to the ECM and did some further checking:

I checked injector continuity. I checked continuity to plug to ECM, all good. I even grounded the blue wire coming from the injector and made it pulse with ignition key on.

Next, I found the check engine light wire to the ECM. (Its BRN/WHT) Grounded the wire at the ECM plug, turned the ignition on and it lit, tellling me that circuit is good.

I researched and checked all power wires-- (2 ORG and one PNK/BLK) power all the time at the orange and ignition power at the PNK/BLK.

Checked ground wires: according to Hanes there should be four, two blk/wht, one tan/wht, and one tan. I only found one blk/wht, one tan/wht, and one tan that were there and gounded.

There's a PPL/WHT wire coming from coil, that shows voltage when engine is cranking- I can't remember what the volts were and I don't know what it is supposed to be either.

I figured the ECM must be shot, so I went to a salvage yard I have dealt with in the past and they have been good to me and purchased a ECM.

I plugged it in and have exactly the same problems as when I started. Anyone ever encounter this? I welcome any input that can get me through this nightmare. Thanks very much, AL

[mike_24_oh]

ok im having the same problem with my 87 sunbird im getting gas clear threw the thorttle body just isnt coming out of the injector is that what yours is doing if so i havent got mine fixed either lol but this is what i was told to check out it may help you but not me first off do you have a distribder or a coil pack well either way you need to have your controll module checked its located in the distribder or under the coil pack your hanes will tell you i have that book its very helpfull thats all i can tell ya but if you get it figured out let me know i hope ive helped you

[toofast4u9100]

Thank you for your helpful tips, but what I found was a green wire at the entrance of the main harness by the battery. Here's what I did:

Went to the library where they had the actual factory repair manual, photocopied the wiring diagrams and trouble shooting flow charts.

The actual Ecm electrical diagram was the ticket. I proceeded to test for power by backprobing with the plugs installed in the Ecm. This is where I found the problem. I had battery voltage with the plugs unplugged, but when I plugged them in, it went to 1 volt. I traced the wire back to the battery. Right in the engine compartment, after the fuseable link, it enters the main harness and thats where the hidden terrior was...little green corroded wire. Fixed that, then where the plugs make contact with the Ecm, I had to clean and tighten them. Next I had a code 13: Oxygen Sensor circuit has a problem. Tested this multiple times and no problem, unplugged the sensor , tested the millivolts with engine off, then ran at idle and engine up to temp, that checked out until I sped the engine up to about 2500-2800 rpm, then the Oxygen sensor went right down to zero volts. I changed the sensor and now the car runs like a dream.

Hopefully, this will help someone else it they ever have similar problems.

[buchholm]

I had the same problem with my 91 sunbird.. it actually ended up being damaged wiring at my distributor. so i changed the distributor and never had a problem again..... I also had melted wiring behind the timing belt housing for my coolant temp sensor