car won't start

[leppy]

I was driving my car, and it just cut out, and wouldnt restart. After having it towed home, I have spark, and plenty of fuel pressure. All my fuses are fine. It seems that my injectors are just not injecting. They all have voltage, so i thought maybe the ECM was bad. After changing it i still have the same problem. Is there something else that may be affecting this ? or is it possible i got a junk ECM. It is a 3.1L I apologize if this was already posted somewhere, i looked for a little while.


I took the valve cover off, and the valves are opreating ok, so the timing chain isn't bad. I've checked for voltage to the ECM, and its fine. I did find something strange however. The ground works fine with the key off, but when the key is in the ON position the grounds on the ECM are bad.. is this normal, or does this mean something is wrong with it.

[xeroinfinity]

I would check the crank shaft position sensor.

You didnt say what year But I would also check for trouble codes.


and Welcome to AF.

[leppy]

it's a 1995 , and i have to wait for payday to rent a scan tool, i don't have one.. and plus with a new ECM would it still have error codes from before, if i haven't had it running yet ?

[xeroinfinity]

Hum, quite posibly just turning it over could throw a dtc.
The reason I said CPS is because it controls injection pulse.

[leppy]

ok well, i rented the tool, it said replace the TPS sensor... so i did, and it started right up, and ran for about 30 mins... i started to drive it down the road, and it died and would not start. Then the SCAN tool said it was the CPS
I changed it, and it still won't start. I also found that if i wiggle my coil my fuel pump comes on and off.... SO that's not good im sure.. i'm not quite sure on how to test them, the book i have doesnt exactly show how for my style.

[xeroinfinity]

Might try a relearn procedure for the CPS replacement.

SECURITY RELEARN PROCEDURE

1. Attempt to start the car by turning the key to the Start/Run Position.
2. Observe that the vehicle fails to start
3. Release key to the 'ON/Accessory' Position. (DO NOT turn key to the 'off' position.)
4. Allow the vehicle to sit with the key in the 'ON/Accessory' Position for no less than 10 minutes.
5. Turn key to off position and allow the vehicle to remain in the 'OFF' position for no less than 1 minutes.
6. Repeat #1 - #5 for 3 cycles.
7. On 4th attempt, car should start.

Note It is SAFE to wait LONGER than the allotted time, but it is not safe to wait less time. I.e. 11 minutes instead of 10 minutes should be safe.

On the Coils check the wiring, sounds like you have a short.

[leppy]

alright, well i tested the ignition module, and convinced myself that it was bad... replaced it for 90$ and the car starts... however... it runs rather rough, and as soon as i put it into gear it stalls... 90% of the time. Also looking through my data on the SCAN tool. I noticed Quad Driver 1 and 4 are bad. I'm not too sure what these do, or if the problem is related. The car will throw a loss of 24x sensor every once in awhile too. But it's brand new. so im confused at least it starts and runs, thats a step.

Ok, so my car runs just fine when the scan tool is plugged in, as soon as i unplug it, my car dies so, im thinking that either i have a short somewhere, or the ECM i got from the junkyard, is... well junk, because it gets a better ground through the scan tool, to the car lighter then wherever it's supposed to go. Anyone have any idea of where to check for a short let me know. It seems to run ALOT better in park or neutral then when in R D 3 2. I'm sure that's relevant, but im not too savvy on electrical systems

Just thought i'd update this for anyone who is looking. I ended up finding a broken wire on the ECM grounds. Located at the front of the engine, close to the starter. After repairing this, Car starts and runs fine. Just an EGR valve problem. Unrelated im sure. Just makes me wonder how much of this stuff was bad, or if it just said that because the computer was shorting out.... Oh well. Live and Learn