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BAD misfire under heavy load

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Old 08-17-2003, 12:11 PM
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Car: 1987 IROC
Engine: Vortec 350 TPI
Transmission: 7004r
BAD misfire under heavy load

Racing my car at the track, the engine developed a horrible missfire on the top end.

Driving around at part throttle, the engine runs perfect but as soon as I give it some gas and get it above 3500, it's like i hit a brick wall. All-- or most cylinders are missfiring badly, you swear I was hitting the revlimiter. If I stay in it, the engine will continue to build rpms but at a painfully slow pace.

Is this ignition? My cap/rotor are fairly new, although I'm still using a stock 84 HEI dist with a 6al box. My wires are old MSD 8mm.
Possible the dist itself is worn out?

Any ideas of what else could be causing this?
Old 08-17-2003, 11:42 PM
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Car: 1986 Sport Coupé
Engine: 305-4v
Transmission: 700R4 and TransGo2
Start with new ignition wires. That's exactly what they do once they get older and putting up more resistance to the spark coming from the distributor.
Old 08-19-2003, 05:04 PM
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Car: 1987 IROC
Engine: Vortec 350 TPI
Transmission: 7004r
thanks todd. thats seemed to have fixed it.

$150 for 8.5mm MSD plug wires! yikes
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