My dads truck is a 93 5.7L ext, lgbd. His intake manifold blew the gasket out on the front driver side of the intake. He replaced the gasket and also the water pump cause i think it still leaked or something like that. But now, when the truck gets up to temp, it starts acting like its mis-firing or fouling out. He said one of the spark plug wires was looking bad but he hasnt replaced that yet just because it doesnt crap out from the start. He's replaced the temp sensor next to the no1 sparkplug but that didnt help. Need a lil help now

 

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350 v8's from mid eighties on up are a little trickier to put intake gaskets in due to the rear coolant passages being plugged. If the truck overheats after gasket replacement I would bet they were installed incorrectly. The gasket has a plate built in to it to stop coolant flow. If installed backwards the plate will block the wrong passages resulting in an overheating condition. If you suspect the coolant temp sensor is bad a simple check is to ground the wire and watch the gauge, if it maxes typicallly sensor wiring and gauge are ok. As far as the missing after warming up a faulty plug wire can cause that. I have seen it many times. resistance increases with temperature.

 

Sounds like it's still messed up.

Mine was occasionally loading until I had the intank gaskets swapped a week ago.

 

THe truck doesnt overheat, it just does something like mis-firing. The plug is fine. Guess i gotta find someone with diagnostics machine to see whats wrong with it.

 

Well, how many miles on the truck?

Might want to change plugs and wires and go from there. I have 131K on my truck and I have changed plugs 2x. I am going to change the wires in the next few weeks. Make sure you don't have a code for a lazy 02 sensor, my truck did and it ran better after I swapped it. A lot of small stuff started going out around 120K miles.