power-drop gremlin

[Chip42]

OK - I'm at the end of my rope on this so I thought I'd ask the crowd and see if anyone can help diagnose this issue.

ITA Civic EX (2000) with OBD1 P28 ECU with Boomslang OBD2b-OBD1 adapter and otherwise stock wiring and sensors (OBD2) - no loose connectors or obvious damage / bent pins that I can find. The car runs fine, but occasionally power just drops out. toggling the ignition or kill switch (3 pole) brings it right back, otherwise it takes a few seconds for the power to return. when the problem occurs, the car will idle, will rev to ~3000, then drop. with the throttle open and clutch disengaged, this will repeat for a little while then clear itself up. when reset, the car will blow a nice fireball, so it appears to have fuel during the problem. All gauges, etc.. stay on, and no engine light on dash (light works).

problem occurs on cool down, warm up, and at speed. Happens anywhere from 3000 to 9000 RPM (car moving) and doesn't appear to have anythign to do with VTEC (happens with P06 ECU, which doesn't supoort VTEC). Occurs typically braking for, or just after exiting corners, but occasionaly it will die mid-strait or mid-corner, which is about as much fun as I can stand... right and left turns, non-discriminant.

we have replaced the distributor, map, TPS, and tried multiple ECUs (P06, P72, P28x2), all stock. We have bypassed the ignition switch and the kill switch to rule them out. we have unplugged various sensors such as IAC, TPS, MAP with no replication and the problem continues. I bypassed the EFI main relay, connecting the ign. power to the pump and batt power to the ECU directly, and the problem will not reset with a toggle of the kill switch. As the ECU would remain energized at all times in this configuration, I believe it to be resulting from a sensor energized via the ECU.

We can't make this occur in the paddock, garage, or on the midway at sebring (shhh). We can do it driving like an ass in a parking lot and at CFRC.

ideas? thanks for any help!

[bonespec]

Have you checked fuel pressure when the motor falls off?

Almost sounds like a fuel pickup issue or a return line issue.

[Chip42]

fuel pressure is good.

[Greg Gauper]

Check your kill switch. These can go bad and cause a similar problem. Search for Jay Griffin's HP Runoffs video to see the sympton (car dies, comes back to life after cycling kill switch)

Also check your grounds. I had a similar problem that would cause the engine to die in left hand corners that I thought was fuel related, and spent a lot of time checking the pick-up, baffles, surge tank, etc. Turned out to be a loose engine ground that would only act up when the motor mounts flexed during left hand turns.

[chuck baader]

Limp home mode? Chuck

[JeffYoung]

That sounds like a ground issue to me. I'd check yours and just add a bunch. They don't hurt.

[Chip42]

Limp home mode? Chuck

most definately - but why??

I'm headed out to CFRC again wed with the S300 dataloging ECU from our FP car to see if I can identify anything.

I'll add a few grounds too. Thanks - see you at Savannah (don't pass me on the outside unless I get this fixed!!)