Distributor for 85 GMC...

**WILMASBOYL78** · #1 05-23-2023, 05:46 PM

My 'mountain truck' is an 85 GMC Sierra Classic...bought it new

Did some upgrades around 2000...4 inch lift Cross Country kit, 35 x 12.50 15 tires, fiberglass cap, 350 Chevy crate motor with Edelbrock Performer, QJ and HEI [big cap].

I have a gremlin with the distributor every once and while...moisture gets in the cap and it won't start [like this morning] I have to remove the cap and spray with electric cleaner and blow off with air hose and then bingo we are back in business.

Trouble is you need to be an acrobat to reach those back spring clamps on the distributor cap

I would like to replace this unit with a small cap version and hopefully one that will have better moisture resistance.

I just came back from a trip to the camp [11.5 miles in 4wd]...glad this didn't happen then.

Any thoughts on a good unit would be appreciated...

One last item...would like to get a battery jump pack for peace of mind...any thoughts on that are welcome, too.

Thanks for the ride...wilma

dustinm · #2 05-23-2023, 07:43 PM

I would just spray the inside of the current cap with a light coat of Fluid Film

**Tommy** · #3 05-24-2023, 01:20 AM

Nice truck Tom !

**Lynn** · #4 05-24-2023, 02:42 AM

Guessing the crate motor means you don't have a computer controlled spark. I had an 85 Suburban and the distributor was computer controlled, even though the carb was not (IIRC).

First, I would figure out WHY you are getting moisture in the distributor. Unless your new distributor is somehow waterproof, I would think you are going to have the same issue.

**WILMASBOYL78** · #5 05-24-2023, 11:38 AM

I don't know why this happens...it is very random. One time the truck sat thru a bad rain storm and wouldn't start. Had to have it towed, dry out the parts and then it started. The most recent issue [yesterday] happened with no weather or dampness...it has been bone dry here

There is very little room between the firewall and the distributor cap...very close. I thought a small cap unit might at least give me more working space.

Does it make sense to apply some type of gel or grease to the rim of the distributor where the cap seats?? Maybe that would help keep things dry...or do I need to vent it to allow any moisture to escape??

Thanks for the input.

**L78_Nova** · #6 05-24-2023, 01:31 PM

Remove the cap and wires, lightly spray everything inside and out with WD-40. Allow to dry then reassemble.

It is amazing how moisture resistant it is afterwards. This is an old trick used by mud boggers.