engine misses at high speeds

[Cheap Truck]

I have a 1983 pickup. It runs fine until it warms up, and I get on the highway. I can be driving at any steady speed, and it will begin to miss at times. It seems that the more warmed up it gets, the more engine misses it has. Any guess as to what might be the problem?

[reb]

One possibility is a vacuum leak which occurs when something heats up. I had a couple of vehicles that had similar Holley carburetors that were notorious for doing that. I would check everything with vacuum hoses, the carburetor mounting flange, and also the intake manifold.
Good luck and keep us posted.

[Cheap Truck]

Thanks for the help.

I replaced most all of the vaccum hoses this weekend. Also distrubutor cap and rotor button, fuel filter, spark plugs, spark plug wires, and air filter. My last resort, other than re-building the carb, was to replace the coil. That seemed to work.
Yesterday was a cold damp day, and it ran fine. Today, it's beginning to get a little " sluggish " as it warms up outside.
Do you have any suggestions on how to set the air/fuel mix on the carb? Also, I will replace the remaining the vaccum hoses later today. Maybe, that will solve the problem. Thanks for the help, Cheap Truck

[ttownjoeshow]

Mine is simular, but i'm thinkin its the air filter, just tryin to get a spare $80 for the K&N lol

[crazycruzer]

I don't think that a dirty air filter will cause your engine to misfire.

[wkobe]

egr can give you a high rpm miss

wayne

[ElmerFudd]

Originally Posted by wkobe

egr can give you a high rpm miss

wayne

egr?

[wkobe]

exhaust gas recirc valve

wayne