I noticed my runner was running like crap the last time this happened I had been getting a white corrision happening in the cap inside the distributor cap on the spark points this has happened twice to me in at least 3 months. I had to scrape it off and then the truck would run fine. This is not a old cap either I think I got it back about 5-6 months ago.

This seems to keep happening why? I haven't put more than 3-4000 miles on it.

 

Bump for ya.
I noticed some of this on mine too...

 

i couldnt tell you... bump

 

Couldn't tell ya, sorry.

 

sounds like possible moisture being introduced from somewhere it shouldnt be

 

Ive heard somewhere that you shouldn't use platinum plugs on a rotor/cap type distributor system, because of the double arc, so if you're using platinums, that could be the cause but not 100% sure, i will do some research on it


because platinum is a less conductive metal than copper it takes more voltage to fire the plug, which that extra voltage tends to "burn" the contacts at a faster rate

 

Some higher quality dist caps use brass contacts in the distributor cap. The aluminum contacts can be prone to getting that white oxide buildup. Is it a factory cap?

I know we used to put silicone dielectric grease on each contact and the tip of the rotor on F*rds during the tune ups. This also reduced engine static on them. This was a thick (like toothpaste) silicone grease. This was factory, not a tune up trick.

I was also told in one of our performance clases to only use platinum plugs in vehicles that were designed for them. This was because of the higher firing voltage required for these plugs. (If you can't get the required voltage to the plug, it's gonna run like crap)

 

It's a factory cap.
I am using NGK V-groove plugs. I already know bosch platiniums don't work well on 3VZE engines. I may just have to get get some stock plugs for now and ditch the v-grooves.

 

Yep, the advice I got from a trusted Toyota mechanic and owner was stay with factory plugs and wires. He said he had problems with the split fire plugs and replacing with factory plugs fixed the problem. According to him, the factory plug wires are the best out there too.

 

The dizzie cap's ventilation might have become poor/blocked, which causes moisture retention and corrosion (that can also lead to the rotor becoming stuck on the shaft) and results in a very rough running of the engine (when the corrosion interferes with transmission of current from the rotor arm.) -- Somebody posted that a certain truck has a ventilation problem in its distributor because of a small window with mesh that gets blocked by debris over time. Somebody else said that removing water and corrosion from inside his civic's dizzie cap was becoming a weekly necessity. I realized that the dizzie cap I bought a few years ago for my Civic has stopped ventilating properly. It has a sort of 'chimney' with a special cap on it that allows some air to pass by not seating completely. I replaced that tiny cap with a 2" piece of plastic tube and hey presto, the car is running smoothly for 2 months (in a very damp winter) with no more removals of dizzie cap to clean the posts inside it. (Before, it would play up only a few days after a clean-up and the weather wasn't so bad.)

Where does the water come from? One explanation might be that it rises off the engine as it heats up and some finds its way toward the distributor and gets past its shaft seals if they are old? It seems to occur in various makes of vehicle so perhaps it happens when the car is parked after having warmed up. Then, as the engine and distributor cool down, water from cold, damp air in the environment condenses onto the metal surfaces, even under the dizzie cap?

 

Gerry is on point for this one i think... i had the same problem on my old Buick.. it would run like a champ until it was raining or i washed it. for me i put a small amount of silicone around the cap to help seal it. i never had a problem with it since.