Distributor Problems

My '96 Sierra has been having problems with ditributor caps and rotors. It's gone through three sets in the last 9 months. I'll replace a set and it will run fine for a couple of months before the motor will start cutting out and I have to intstall a new one. The old caps have a blueish corrosion type substance on the contacts. I've replace the plug wires and the coil but the problem persist. The truck has a 5.7 Vortec with about 146k miles on it. Has anyone else experienced this problem or be able to give me some insight?

My 91 Sierra was acting like that and spark knocking bad and I found that the distributor shaft had some side to side play, which meant the bushings were wore in the housing.(grab hold of the rotor and try to shake it) A mechanic told me my shaft had some cracks on top just beneath the rotor button which causes irractic firing. I replaced both the housing and the shaft and working better. Hope this helps.
Kevin

yeh just recently my truck nearly died, or so i thought. and it turned out that the distributor itself wiggled out of place cuz of worn bushing. which caused the engine to run like crap cuz the timing was all messed up. took it to a mechanic and for $60.05 it runs better than it has in a long time.

My '96 Sierra has been having problems with ditributor caps and rotors. It's gone through three sets in the last 9 months. I'll replace a set and it will run fine for a couple of months before the motor will start cutting out and I have to intstall a new one. The old caps have a blueish corrosion type substance on the contacts. I've replace the plug wires and the coil but the problem persist. The truck has a 5.7 Vortec with about 146k miles on it. Has anyone else experienced this problem or be able to give me some insight?

I have a 1996 GMC Sierra 1 Ton Dually with a 454 Vortec Engine, I too had a problem with the distributor and it was wobbly. Removed the distributor and replaced with a new one. Problem is the hole in the intake where the distributor goes measures 1.5", the old and new distributor measures 1.250". Has anyone run into this problem before?
I went ahead and replaced it with the new one the truck runs even better than before but with a loss of gas milage (from 10 mpg to 7 mpg).
Original reason for repairs was I has a water leak between the intake manifold and head.
Any sugesstions???
Thank You,
Ron

I have a 1996 GMC Sierra 1 Ton Dually with a 454 Vortec Engine, I too had a problem with the distributor and it was wobbly. Removed the distributor and replaced with a new one. Problem is the hole in the intake where the distributor goes measures 1.5", the old and new distributor measures 1.250". Has anyone run into this problem before?
I went ahead and replaced it with the new one the truck runs even better than before but with a loss of gas milage (from 10 mpg to 7 mpg).
Original reason for repairs was I has a water leak between the intake manifold and head.
Any sugesstions???
Thank You,
Ron

Need to rephrase the question. I understand the cap and rotor play with a worn bushing. I was also refering to where the distributor goes into the hole of the manifold and with it NOT bolted down you can move the whole thing back and forth about 1/4", I thought distributors were supposed to be snug inside that hole??? I am guessing a mfg. defect and no way to make sure the distributor is perfectly straight.
Ron