ECM Failure?

[cmongfe]

Hello again Festanation, I have only one item left that I have not looked at or considered. Is it possible the ECM failed in my Steva? It will not idle now, only stays alive at 1300 RPM or more, I have replaced every sensor, injectors, distributor, fuel pump, the ISC, coil, filters and yet it won't idle, smells like its running rich and the fan comes on now even when the engine is cold. I'm really grasping at straws now and if I can't fix it, I will convert it to a carburetor! Could a faulty ECM be behind all these problems? Thanks!

[bravekozak]

You need to borrow an ECA tester from someone. Ask on the forum.
Then you can probe each of the signals going in and out of the ECA, to verify if they are within specification.
Good luck.

[bhazard]

Never seen one of those. Looks like it's for a carby anyway.

[Advancedynamix]

Hello again Festanation, I have only one item left that I have not looked at or considered. Is it possible the ECM failed in my Steva? It will not idle now, only stays alive at 1300 RPM or more, I have replaced every sensor, injectors, distributor, fuel pump, the ISC, coil, filters and yet it won't idle, smells like its running rich and the fan comes on now even when the engine is cold. I'm really grasping at straws now and if I can't fix it, I will convert it to a carburetor! Could a faulty ECM be behind all these problems? Thanks!

Check the condition of the ground wires throughout the car. Your problem sounds like a bad ground, or multiple bad grounds.

[cmongfe]

Thanks again Kozak, I 'll see if I can test it but I'll probably convert it to a carb(s) like you did, that was so cool! "G".

[TominMO]

Not so likely the ECM has failed. Much more likely is a simple error of some sort; like cam timing or spark plug wiring. First I'd triple-check that the plug wires are going to the cylinders they are supposed to go to. Then check cam timing.

Also as Charlie said look for ground issues, after you've checked the plug wires/cam timing. BTW if your car is timed properly (both ignition and cam), the disty should be somewhere in the middle of its adjustment arc, not all the way advanced or retarded.

Converting it to a carby (which will have its own problems too) is far more complicated than getting your EFI car running right.

[Movin]

At least one sensor is faulty or not getting engine heat to it for your fan to be running all the time.

A pin out test of the ecm is all that is needed. Look at the wiring diagram and start with power and ground.
Make sure they all measure right while the car is running. There are ford test procedures for each sensor.
Check the voltage readings at the correct wires going into the ecm, again with the car running.

You can get your ecm tested but it will likely test just fine and you will have to test all inputs anyway.

A $3 harbor freight meter can do this just fine for you, just be easy with the cheap leads while back probing your ecm connectors and keeping the engine running haha. Test sensors that calculate fuel mix first..air temp, coolant temp, tps switch, air flow, RPM..

[scitzz]

I bet the fan switch is unplugged at the water outlet to cause the fan to run. I doubt it is ECU.

You did all that work, I betcha something is up there. Running rich, won't idle below 1300 RPM. Smells rich....

I really think Tom and Advanced are right on track. Wire connections, grounds, timing.

[Movin]

Sooo.. those things would not show up on a ecm pin test....nice.

[scitzz]

I bet the fan switch is unplugged at the water outlet to cause the fan to run. I doubt it is ECU.

You did all that work, I betcha something is up there. Running rich, won't idle below 1300 RPM. Smells rich....

I really think Tom, Advance, and Movin are right on track. Wire connections, grounds, timing, pin test sensors.

Sooo.. those things would not show up on a ecm pin test....nice.

Fixed it! Missed your post! I think I had the page open for a few hours before I responded!

[Movin]

Thanks! I was feeling like the invisible guy on that page Lol. Sometimes these things actually take a little testing or parts swapping to figure out.

[cmongfe]

Ok, I decided to go for it, I'm switching over to the Weber carb conversion. So far, so good.