3 replies to this topic

[Keith Novak]

I may have fixed this somehow by wiggling things but I'm worried it will come back...

The engine would pull fine up to about 3500 rpm, and then acted like it wasn't getting any gas. It did it once loading it on the trailer. I redid all the grounds and I thought I solved it. It loaded on the trailer just fine, then it did it within seconds of my first session. For 3/4 of a lap it came and went, died completely so I parked it at a corner station, then started a minute later and I limped it back to the paddock. It wasn't like a brief intermittent cut-out. It was many seconds of little to no power, so much so that a couple times the only way I knew it was running was the tach.

I didn't have this problem before putting in the new engine. I didn't change any fuel or air related parts when I moved them over from engine A to engine B.

Plenty of fuel. Idle a touch high but no vacuum leaks we could find. 5 people checked every connector, hose, fuel line connections, etc. No rags in the crossover tube. No mice living in the airbox. IAC resistance was normal. We raised the back end, I put it in gear and reved it with my foot on the brake and it died low 3000 rpm again. Flow looked good out the test port. We checked the fuel pressure with the car off and did the ghetto dyno again. Fuel pressure was fine there too and it didn't stall. Then it ran fine in the next session.

Does this sound like a bit of crud working through the fuel system, a loose connection that we fixed with all the poking and jiggling, or a symptom of another fuel, or air related switch/valve having issues? Bad gas? We were stumped but figured someone else must have experienced this.

[Tom Hampton]

My dad had almost the exact same symptoms on his motorcycle. Only at the track, only under heavy loads. Turned out to be crud in the fuel.

[Ron Alan]

Had a similar thing at the Art of Racing weekend...cut out, only ran to 3000rpm, died, then started again, then died. Fuel pressure was good. Changed the only electrical spare part we had...coil pack...BINGO!!! Has run fine since! Didn't miss a session!

[Keith Novak]

Thanks. I have spare coil packs and plenty of gas. I'll swap both out at the track this morning and hope this nasty little gremlin is gone for good.