[Drbonzai]

I'm new here and i have a similar problem with my cap and rotor that i just can not seem to figure out. I work on a lot of vehicles and have done a lot of research trying to find out why my truck is destroying the inside of my cap and rotor but i am at a loss. I have replaced the distributor with and aftermarket aluminum one but for some reason it is still coming up with a corroded cap and rotor within a few months of putting a new one on. It happens in summer or in winter and the truck will still start. It starts hard and you can hear it most definitely has a miss and i've replace the coil and ICM module with brand new ones from chevy. I have been going through and checking that none of the grounds are broken and cleaning them (found all the ground locations in the factory manual). I have also noticed that one of the screw heads inside the new aluminum dist is completely rusted like it is getting moisture but I just have no clue how this could be happening. I also live in California which is definitely not a very wet or humid/cold state by any means. Any suggestions or help would be greatly appreciated.

 

[Drbonzai]

It does have vents i have checked those and they are clear, I've also tried factory distributor cap and aftermarket and both did the same. i have pictures of the last cap and rotor and the inside of the aftermarket distributor if that helps. Thank you very much for the quick reply. The pictures are kind of large so i didn't know if i should post them, looks like i can only fix one picture per post.

 

[Drbonzai]

well thank you for your help and i will keep trying to figure it out. I am thinking maybe something with the PCV system could be putting lots of moisture in the distributor if it wasn't functioning right but it passes CA SMOG just fine so i doubt it. no CEL.

 

[Drbonzai]

Wow this is a truly amazing write up and i GREATLY appreciate this man! This is really the exact information I need and i am going to check the vents on this aftermarket distributor tomorrow! I have long wondered if that AC hose might indeed have a condensation issue cause it is the suction side of the AC system and these trucks run the AC pump on and off to keep the defrost air dry even when you have the system on defrost and heat in the winter, so in theory is could always drip a little condensation but i've never witnessed it myself. I am most definitely going to put some foam around it now. I don't know how you found all that as i have searched and searched for this for a couple years now and just had to deal with changing the cap n rotor and dealing with a misfiring truck till it got to the point it wouldn't start anymore. Also when it gets that bad i do get an interment P300 code i believe, or whatever the multiple misfire code is. On the note of make sure the PCV system is working properly I have check the pcv valve itself and its fine and passes smog but I noticed the tube from the pcv valve goes to a vacuum actuated/switch/device. Is there anything else i can check on this system you know right on hand? I am going to check my helm manual tomorrow when i am back at the shop but i thought i'd ask. I will also tell you my distributor cap has that exact symptom he spoke of with the white residue and destroyed terminals that are also a very whiteish colour. I really appreciate your search and help on this and i think considering a billet dist is only 90.00 i will order one of those if my current one has anything that doesn't look 100% right to me again. Thank you!

 

[Drbonzai]

It is truly amazing what the right google thread will find you. I checked my factory manual and to check the crankcase ventilation system you just take the pcv valve out of the valve cover, put your finger on the valve and check for vacuum. I am going to be working on it today and i wanted to show you guys the picture of my distributor and cap n rotor to show you the frustration i was dealing with. So happy to be able to make those changes to my engine now and really move ahead with this. i have loved this truck for many year and even have a completely rebuilt interior in it so it not running right for so long was a very frustrating thing. Thanks again.

 

[Drbonzai]

 

[Drbonzai]

i am just going to order a new billet one i don't really want to spend any effort cleaning it. i have not removed it from the truck yet i want to wait till the billet one gets here and i can mark exactly how to line it up when i remove it. It will be a few days most likely till it arrives but when it does i will make sure to report back and take pictures of how it's designed. It was a cheap aftermarket one from some autoparts store so maybe it's not up to par.