4.3L GMC dist screen problems

This message is a reply to an archived post by George Marsh on November 18, 2013 at 14:31:29.
The original subject was "Re: 4.3L GMC".

{ OP has suggested that he will leave the distributor vent screens in place to combat road dust} Gee George, Everyone else (including GM) thinks they should be removed) I'm going to pull mine. Please let us know how you do with them still in place. Maybe it will be a couple of years before you have problems? (boy do I ever hate intermittent issues...)

Hey Jason, I have the same problem. Let me know how you make out please.
Thanks

Seems to me that in gas/ spark fired marine engines those screens ,as well as venting the distributor also contain sparks that ocurr within the distributor.

Jason,
I've had 2 GMC trucks that have had distributor issues, some times in 20-30K. My current truck the OEM lasted 25K, so people don't preach that I should replace with DELCO. I went to Auto zone and bought s 5 year dist. Well that one went bad in about 30K. Auto zone gave me a new one. The distributor had a gray like power inside and out. Someone on YT suggested using grease to seal dist, so I did.

I have about 10K on this one, so far so good. My issues seem to follow extremely high humidity conditions, either rainy or a quick warm up with humidity condensating on floor of garage.

I'm sure I'll have problems in the future, will post when I do. I was waiting on GM to make a distributor-less version of the 4.3L, but I ran out of time. 2007 was the last year for the classic body style and I didn't want a step ladder to get to my tool boxes on the side of truck.

I find it odd that someone remembers what I post.

Also kind of odd to find someone with same last name. Have a great day.

george

This was a big problem on the medium duty trucks until GM came up with a new rotor. Once the new rotor with a fan built into the bottom side was used I no longer I had a problem with corrosion causing the reluctor to come loose on the shaft. Before the change I had changed several with less than 20,000 miles on them.

I serviced 11 trucks that used that distributor. I used to buy them two or three at a time. I would get a call that the truck was back firing and had no power. I changed quite a few of those distributors with the truck setting on the side of the road.

When that distributor was first used in those trucks in 1990 Schwans started having engines blown pistons. It soon got to the point they were losing more than one engine a week in their fleet. GM was blaming Delco Remy and Delco said it was a problem with the propane conversions. GM finally put a truck on a dyno and sprayed some water under the hood. They blew the engine in a couple on minutes. The same distributor was not causing the same problems with the light duty trucks where it had been used since 88. The difference in air flow patterns caused the problems in the larger trucks. The result was that Delco Remy replaced the distributors in all 90 and 91 Shhwans trucks.