Kevin Koby

The strange issue that I am having is that sometimes the car runs and idles perfectly. Other times, it idles / runs really really rough. Usually if it is let to idle on its own (when it is running rough), it will stall, or at least come close to it. What I have narrowed it down to is the ECU/ECM. I noticed that when I removed it from the dash, and tapped on the metal enclosure (fairly light taps) that the rough idle started, and the motor started choking. I already replaced the computer, and still have the same issue. It has a performance chip in it (hypertech). I actually have 2 perf. chips, and they both seem to do the same thing. I would think this must mean some kind of loose wire or pin, either in the harness or the performance chips I have? Any ideas on how to test it further? I wouldn't want to buy another hypertech if I do not have to. Also, the car came with the hypertech, I do not have a stock one on hand. After searching the forms I checked the grounds on the heads on the driver side rear of the motor, they seemed strong, and wiggling them while motor was running did nothing. Thanks for any ideas!

The engine / car is:
88 Camaro IROC-Z, 5.7L V8 350 engine.

Kevin Koby

Anyone? Maybe as a start someone could get a pinout for the computer plug? Was hoping to at least have some ideas, I plan on attempting to fix it this weekend. Thanks.

David King

Hello Kevin,
Did you ever get that fixed? I've got an '82 Corvette with TPI/ECU from an '89 Iroc. It has started to do the same thing that you described. I've replaced the fuel pump, rebuilt the distributor, and a few other things. I was about to replace the ECU . . . let me know!

David

silverstang84

Anyone know the outcome to this problem? It's very similar to what my car is doing

rusty vango

you need to throw that hyper tech chip away. many members have had trouble with them. you can get a chip from "tuned performance" he does top notch work

silverstang84

Hey guys, I had to bring this post back from the dead. My car has the same problems as the op, and I'm on my second ecm... It's driving me crazy.. I tap on the ecm case and the car runs badly and the ses light flickers.. Is here a way to fix this?? I've checked all the grounds and cleaned all connections at the ecm.. If it's a loose connection inside the ECM.. Can I take the metal cober off and repair the connection? I'm going crazy and I'm on my second ECM. Any help is greatly appreciated. Thanks

rusty vango

if you had the misfortune of buying a "cardone" replacement ECM....... THERES your problem. I cant stress enough the importantce of NEVER buying anything they offer. I find that the packaging is worth more than the contents. having said that .you might find a electronics repair person to fix what is wrong with your ECM.

silverstang84

Thanks Rusty.. Unfortunately, it is a Cardone.. A person from this board contacted me about the problem and I may be getting a oem ecm. I'll post with results..

Joshua Anderson

I had the same problem turned out to be fuel injectors