Situation: 1st points race of the season this Sunday.

Symptom: "breaking up" when warm. Acts like a burn't plug wire. Intermittant power loss.

What I know: Scanned computer and only one problem was found (with the 3-2 downshift) so that doesn't matter becasue the car began as an M6 and is now an automatic with manual valve body and no electronics on the tranny.

New plugs. Tonight installed new wires.

O2's are questionable but I don't think they have been working for over a year anyway so gas mileage is crappy and idle is rough.

The problem is a lack of power like it is dropping a cylinder.

There are new valve seals installed. Removed bur on each valve. Coil tests fine. I need a direction to look in. Throwing parts at is gets expensive.

 

Sounds like something that is getting heat soak. You might wanna try checking, or even un-plugging your MSD box to see if it "clears up".

My buddy had that prob. with his blown '94 GT. When it got warm, it would "break up" like you stated, and at times wouldn't even start back up. Turned out it was his ign. box.

Not saying this is your prob., but maybe someting to try.

Dave

 

Thanks for the suggestion. I will try that tonight. Anyone else?

 

Two other items that can have heat soak problems are the ICM and the opti.

 

Here's what to do.

First, pull the coil bolts and take sandpaper or a Dremel and clean all your ground connections that bolt to the head. There should be like three of them there. Then clean the pcm grounds. It is located on a stud that screws into the passenger side inner fender area. You have to pull the stud out to clean it as it is just a sheetmetal screw on the body side and it gets cooroded super easy. I replaced a LOT of parts before I found that one so I hope it works for you too.

Let me know if that works for you.

 

Also check the grounds to your MSD box too.

 

Did you figure out what was wrong yet?

 

Cleaned connections. Tooke the MSD box out of the lop and it still did it. Installed new ICM and the problem seemed to go away for awhile.

So.... I went to the track Sunday. On my first burnout the car started coughing and almost died. Ran 13.5 at 100. Normally runs 11.8-12.2 at 110-112.

Anyway, it was consistently slow. My normal 1.60 sixty foots turn into consistent 1.78 sixty foots. My normal 7.5 1/8 mile at 88-90 turned into 8.3 at 83. But something is extremely wrong.

The last electrical item to really swap out is the opti that I can think of.