Hi All,

After the shop rebuilt my motor, we've been having
problems with the way it's been running. I will
run fine for a while, and then run rough. When
I start the car, the tach will bounce down (1000 down
to 600) and sometime cut out. We have replaced the
harness, not the problem. Any idea on how to trace
down the problem. The car is an 83.

I seems that the car is losing timing, but from where?

Sid

reference sensors ? maybe the height is wrong or bad connections ... ?

we need a little more help about when it is doing it.

Idle, part throttle, full throttle, cold, warm, hot, in a turn or level ground. Does the RPM drop off and stall. Intermittent or can duplicate if you do X,Y,Z?

If it's the same thing as it was doing at Blackhawk, it would variably run on 2,3, or 4 cylinders, part or full throttle. We replaved the fuel rail + injectors, AFM, DME, and now wiring harness. I like the ref. sensor idea. I have a spare set if you are risking coming out to Gingerman this weekend.

I am being driven to drink, actually more like
walking since my car is working.

I thought we had it working, and, I packed up
for gingerman. Got 2 miles and the car died
on the highway.

Basically it seems to be something in the wiring
harness, not the engine, but somewhere else.

The symptoms are the following.

1. I could get the car to die when I closed the
hood and pushed on different parts of the front.

The lead to the idea that the cable was somehow
pulling on wiring harness since it was zip tied
to it. Remove the zip ties and isolated the cable.
Fixed the engine dying when closing the hood.

Step 1. Replace the sensors, dme, not effect

Step 2. Thought that the it was the ground to computer,
wired in a secondary ground. No help.

Step 4. Secondary ground to the coil, did not help.

The car either runs fine for a while and then suddenly
starts to die with tach bouncing down.

At this point I'm out of idea (so are my high priced
mechanics! It driving them crazy also)

I figure the next thing to do is create a basic harness
to replace the one in it.

Any chance it the computer. It already been replaced,
it a newer one. Also Nick tried it it did not make difference.

Help!....

did you try to reset the sensors? The speed and ref sensors could be too high and not always albe to read the tab on the flywheel for TDC and the teeth on the stater ring.

Couple other things to check.
1) DME relay (assume it was aready done)
2) Car system power. Faulty ingnition switches can cause the car top stop and loose all electric power.