missing/rough running round 2

[8cam]

Further testing, I put the meter on D7 off the ECM and with no key in the ignition, OL. With key in but off, OL. With ignition turned ON, I get a cycling resistance to OL, repeating over and over. No idea what that means.

I also figured out which key code I have, and for $26 from Ecklers I can order the VATS bypass which is nice and clean, no soldering required. I wouldn't miss it at all. But the question is, would that fix the problem? For 26 bucks I'm inclined to order it anyway.

[QB93Z]

I don't like to make guesses in trying to diagnose a problem long distance, BUT, we had similar symptoms or a ZR-1 here is WAZOO recently. It turned out to be a failed ECM. Do you have access to another ECM? I would not recommend buying a replacement until the issue is fully ID'd, but if you can borrow an ECM and run it for a period of time, it may help isolate the issue.

Any year ECM will work, just put the chip from your car into the "test" ECM.

If you don't have access to an ECM locally, PM or email me (jim@gizmosart.com).

Jim

[QB93Z]

Originally Posted by 8cam

Further testing, I put the meter on D7 off the ECM and with no key in the ignition, OL. With key in but off, OL. With ignition turned ON, I get a cycling resistance to OL, repeating over and over. No idea what that means.

I also figured out which key code I have, and for $26 from Ecklers I can order the VATS bypass which is nice and clean, no soldering required. I wouldn't miss it at all. But the question is, would that fix the problem? For 26 bucks I'm inclined to order it anyway.

If the car starts, it is NOT a VATS issue.

Jim

[8cam]

There have been times when it has cranked but not started. Then next time it starts, runs and then stops cold. Then times when it runs like total crap. According to the WSM, with a broken VATS circuit it will still crank. At this point it could be a flaky connection/ground in that circuit or like you said, possibly a bad ECM. Still not certain exactly, but I REALLY appreciate the offer! I need to do a little more digging.

[8cam]

I did order the VATS bypass from Ecklers, although 10 bucks for shipping a small light part is ridiculous. But I like that option better than breaking out the soldering iron. Meanwhile I'm cleaning grounds and checking all the connectors. I hate electrical issues.

[WARP TEN]

Originally Posted by 8cam

I did order the VATS bypass from Ecklers, although 10 bucks for shipping a small light part is ridiculous. But I like that option better than breaking out the soldering iron. Meanwhile I'm cleaning grounds and checking all the connectors. I hate electrical issues.

Shipping and Handling has always been a big profit center for mail order sellers...Bob

[RussMcB]

Originally Posted by WARP TEN

Shipping and Handling has always been a big profit center for mail order sellers...Bob

Last night I planned to order the similar Mid American part (with the toggle switch - I thought it would be nice to leave VATS working most of the time, and deactivate when troubleshooting), but after adding $17 shipping it was close to $80. They lost that sale.

[rkreigh]

sounds like a bad ground, ecm, or wiring problem with the spark module

I had a 93 that would do this if is wasn't driven enough

the dis module would code, it would run rough or cut out and then start back up and run fine

definitely get a scanner on it and start wiggling wires!

[batchman]

Originally Posted by Starman

I saw where you went after the ignition, but did not see where you checked the Fuel Injectors. But they are not typically intermittent.

When my injectors gave up the ghost it was similar to the OP's situation. Ran fine all day at a school, last run it broke down a bit at high rpm. Cooled off and was fine on the way home. Next event (one week later) it was fine in the morning runs, phew, but then came the afternoon - idled reasonably maybe just a touch "off" but when I hit it it was 7 cylinders for sure.

At this point with the e10 gas I'd look pretty hard at any OE injector. Measure 'em and it may well tell the tale.

Good luck,
- Jeff

[8cam]

I installed the VATS bypass from Ecklers this morning, and it's perfect. Drove the car a good long time, got everything nice and warm, not one problem, not one hiccup, running absolutely perfect. I swear it's running smoother than it did before. I tried multiple stops and restarts, cruising, full acceleration, gentle pull from a stop, and it's back the way it's supposed to be. Apparently my VATS was flipping out, causing erratic running issues.

Very happy with the $27 fix, not so happy with the $10 shipping. But for all in less than 40 bucks not too bad.