another egine miss

[Arnold Greene]

Have you checked/changed the high side chip? It may be hitting the rev limiter.

[randy wilson]

Arnold, it's on the low end of the gear change right after engagment, with a clucthless. From about 7,500 to 8,200.

[FED 387]

when u say trigger gap do you mean the wheel on the crank?? if so it should be at least(from what I've been told) .060 to .080-- the more gap you can run the better do not know why but what I always was told--- big block engines especially ,the cranks flex at higher rpms closing up that air gap !!!! have you tried twisting the wires on the pick up??? the full length this can help with RF interference

[buzzinhalfdozen]

Randy, yes get out your tester, lets look at the easiest stuff first. Though there is an almost unlimited list of things that could be causing your issue I like to start with the simplest things first. The tach and datalogger both showing eratic engine RPM in my mind indicates an ignition issue. Posts indicating interference are of interest, any signal getting into the box can cause problems. Have you changed the routing of any wires on this car? Alts. fans,coils ect. too close to the trigger wire can "leak" into the wires. Twisting the wires is a good idea though most are already twisted. Joe

[randy wilson]

Thanks guys, and will try all til I find it. Been busy with the business, and Steve just moved to a new house and farm, and has a beautiful shop on it, and that's where the car is sitting now. It's so hot, we don't feel like going to Eddyville, but when we do, will let you all know. Can't be that serious, but can sure be frustrating. Too hot to race. Heat never bothered me when I was young, but now it's a big deal.

[BlueOval Ralph]

Could either be lean or rich at that point in fuel curve , don't forget at the bottom of the gear change you have just had a big change in booster draw.

Originally Posted by randy wilson

Arnold, it's on the low end of the gear change right after engagment, with a clucthless. From about 7,500 to 8,200.

[randy wilson]

Thanks Ralph, didn't think of that. Was a little lean.

[Michael Compton]

When I had a miss, mine was at the top of high gear and you could hear the miss and see it on the racepak graph. It was crazy. Turns out we had a regulator and fuel pump going south. When under extreme load, the regulator and pump were causing flucuations in the fuel and making the motor miss because of no fuel. Might be something to check out.

[randy wilson]

Thank you! Will do. The fuel pressure on the graph never flucuated though.

[FED 387]

just remember that there is a difference between volume and pressure!!!! FED387