- 1,547
- 16
- Jun 28, 2002
-
Aurora,
ON, Canada
I recently did a turbo conversion on a friends 93 ES. Things are great except something is not right.
Let me describe the car fully first. Compression is good. 150-150-150-150 +/- 3psi across the board with strong first two cranks. The spark plug wires are good and so are the plugs. There is a second set of injectors in the rail now as I thought the first ones might have been bad.
The issue: At idle, the motor runs like a bag. Cylinder #4 doesn't make power. If I take the #4 plug wire out during idle, the engine doesn't bog one bit but the spark plug wire is arching. If I take plug wire #2 or #3 out during the idle, the engine bogs down a bit. If I take plug wire #1 out, the engine dies completely. I believe this is because #1 and #4 fire at the same time and no power is being produced during that stroke from #1 or #4.
Now with all the plug wires in, the engine revs up well and hard. With #4 wire out, it bogs when you rev it up. So basically #4 isn't "working" at idle but is fine once you start driving the car.
I thought it might be an injector. It wasn't. I swapped the set out for a working set and still the same issues. I tried replacing the plugs (always a good idea) and replacing the wires (from another working motor), no difference.
My thoughts are the ECU is a bit messed up, the transistor is messed up and then someone mentioned the resistor pack possibly but how would that affect the idle and not the free rev.
I manually turned the CAS over with my finger and the spark plug wires fired perfectly (all 4). All the injectors "clicked" when I did this as well do I don't see an issue there. It's really just blowing my mind.
Logically, my only explaination would be the ECU. Once the idle switch is "seen," the map for #4s injector is contaminated and messing things up. Once the idle switch is off, the new maps are given and the thing runs fine. This is all theoretical by the way.
Anyone want to put their 2 cents in?
TimG
Let me describe the car fully first. Compression is good. 150-150-150-150 +/- 3psi across the board with strong first two cranks. The spark plug wires are good and so are the plugs. There is a second set of injectors in the rail now as I thought the first ones might have been bad.
The issue: At idle, the motor runs like a bag. Cylinder #4 doesn't make power. If I take the #4 plug wire out during idle, the engine doesn't bog one bit but the spark plug wire is arching. If I take plug wire #2 or #3 out during the idle, the engine bogs down a bit. If I take plug wire #1 out, the engine dies completely. I believe this is because #1 and #4 fire at the same time and no power is being produced during that stroke from #1 or #4.
Now with all the plug wires in, the engine revs up well and hard. With #4 wire out, it bogs when you rev it up. So basically #4 isn't "working" at idle but is fine once you start driving the car.
I thought it might be an injector. It wasn't. I swapped the set out for a working set and still the same issues. I tried replacing the plugs (always a good idea) and replacing the wires (from another working motor), no difference.
My thoughts are the ECU is a bit messed up, the transistor is messed up and then someone mentioned the resistor pack possibly but how would that affect the idle and not the free rev.
I manually turned the CAS over with my finger and the spark plug wires fired perfectly (all 4). All the injectors "clicked" when I did this as well do I don't see an issue there. It's really just blowing my mind.
Logically, my only explaination would be the ECU. Once the idle switch is "seen," the map for #4s injector is contaminated and messing things up. Once the idle switch is off, the new maps are given and the thing runs fine. This is all theoretical by the way.
Anyone want to put their 2 cents in?
TimG
