The hesitation that some 3rd gens experience at, or, around 3000 rpm is a pain. It is a relatively common problem, probably related to at least one design glitch. I have read about various fixes people have tried with mixed success (kind of like an alergy or genetic disorder), however, most of that information is a little old. My car developed the stutter around 24,000 miles and I have tried many of the fixes that I have read about.... improving grounds, changing ignition wires, plugs etc. but nothing has worked. I have not gone to the extreme of replacing the ECU. Does anyone have any new ideas on for to get around this problem??

 

i'd try grounds first. if that doesn't work. its time for an apexi powerFC

 

the hesitation is caused by current spikes in the engine ground circuit (just like the 86-88's). the ecu is grounded to the top of the engine and then the engine is grounded to the body then battery. the fix which should get rid of about 90% of it, is the following.

1. there is a wire between the rear of the upper intake and the body.

remove it, clean and put dielectric (sp?) grease on the contact. take the tab off the body of the car. clean its mating to the car, and also grease. make sure the wire clips in tight. tighten all the bolts

2. the negative battery cable bolts to the engine block under the ac bracket. clean grease and tighten.

3. the relay box next to the shock tower is on a big metal bracket. clean and tighten the bracket to car surface.

4. clean and tighten the battery cable ends

#1 and #3 are the most critical i was able to fix 85% of mine just with those 2, they are also the easiest to reach.

the reason for the grease is to keep the surfaces from corroding, i didn't grease mine, and had to do it again a year later.

the next step in the diagnistic chain is to replace the ecu, and after that the engine wiring harness



mike

 

OK, so I first tried cleaning up the connections on the ground cable that runs from the extension manifold to the fire wall but the problem remained. Before going on to the fuse box, I bought a length of 8 gauge copper wire, fitted it with spades and bolted one end to a vacant hole at the back of the extension manifold and the other end to the fire wall where the existing braided engine ground attaches. Presto, no more hesitation!

 

I'd be surprised if it doesn't come back. I did your fix about a year ago. I corrected it for a month or so then it came back.





It doesn't bother me much any more to be honest with you. It's part of the cars personality and I have just accepted it. Until I gp w/ a Power FC of coarse.

 

Clearly the hesitation is due to in sufficient grounding (at least in my case). If it comes back then it suggests to me that another ground is faulty and needs work. Obviously, finding the bad connection becomes problematic. How would replacing the ECU help when the bad connection, or connections, still exist?

 

Well everyone I know that has went with the PFC no longer has the problem.

When did you determine it to be a grounding problem?

I think that is part of the problem but certainly not it. Think Injectors.

 

Well if it does come back try this:

Dissconnect the O2 sensor from the back of the UIM. This does it just fine for all of my big hesitations every time. I discovered this when driving around one day with Rays Wideband. The car never stuttered one time. Took it out and plugged her back up and bam stuttering like a big dog. So give it a shot.



-Rikki

 

i think the power fc mamages the voltages differently, the stock ecu puts a lot of current thru those grounds. some sort of dielectric grease will make the fix last a lot longer



mike

 

Yeah the grease is good. But when you get rid of the O2. She is smooth oh so smooth.



-Rikki