Chronic no-start problem..

[s373n_rcr]

My 89' with 350TBI and HEI ignition has been a nightmare for the past two months or so. Last summer I replaced the magnetic pickup coil after the truck died one day. Everything was fine until about a month into the winter season when the it wouldn't start. Couple quick shots of WD40 under the dist cap and it's fine again, for a few days anyway.

I have now replaced the cap and rotor three times and still persistently get this no start problem. Everytime it happens the WD40 under the cap fixes it, at the least for a few starts, the most a few days then it happens again. I'm getting sick of climbing into the engine bay so often, especially in the winter weather.

When I replaced the pickup coil I cleaned out the two little screens in the distributor base. Could these be letting moisture in regularly? I was debating on plugging them with grease to prevent condensation from rising into the cap, but then you'd figure GM engineers put them there for a reason, right?

Any ideas? I'm getting frustrated......

Thanks

 

[TJS]

When you did the pick-up did you put a GM one in. Also you should change the module at the same time with a GM one. Also I have seen some magnets crack on the shaft for the reluctor as well. If so shafts with magnets are avail . at GM as well. Hope this helps. Also how old is the external coil.

T.J.

 

[dirtwarrior17]

definetly electrical because of the wd40 trick...

When you did the pick-up did you put a GM one in. Also you should change the module at the same time with a GM one. Also I have seen some magnets crack on the shaft for the reluctor as well. If so shafts with magnets are avail . at GM as well. Hope this helps. Also how old is the external coil.

that should fix it but if it doesn't i don't know what will. wd is water dispersing and if it works everytime you spray it in and then dies in a couple days i would say you got some kind of moisture somewhere.

 

[s373n_rcr]

I don't believe the pickup coil was genuine GM. The main coil is original (1989) as far as I know or can tell and I did inspect the magnets on the top of the shaft while I had it out. They were fine.

The pink and white wires that run to the module look fairly stressed given the position of the distributor for the correct timing. The connection at the module is at about 15degrees past top if looking from the front of the truck. Can you buy these wiresets separate from the coil or module themselves? The only other thing I can think of is if the module needs replacing itself. It still makes me wonder why a simple WD shot takes care of it everytime, albeit temporarily.

 

[1985K20]

I dont want to call myself an expert but it seems to me that your problem is obviously moisture getting in the way.Get a can of ignition system sealer at napa and spray that all over your distributor.

If that does'nt help any, well i dont know!

 

[diesel4me]

try the module...

My friends 94 Chevy truck with a 4.3 did exactly the same thing--it refused to start sometimes,other times it started fine and ran well,once you got it to fire up with starting fluid if it refused to start,it would run fine,but he hated to drive it anywhere,not knowing what the problem was..he sent the truck to several garages,and the dealer when they gave up-
-he had the fuel pump replaced,new gas tank because the old one leaked when they removed it,all the fuel lines were rotted,200 bucks later it refused to start even with new lines from the tank to the injectors--he tried used injectors,map sensor and no improvement!-it STILL would not start at times--it seemed to do it more on rainy or damp days too(of course!)--
-he refused to beleive the module was at fault,since it always had good spark--but on EFI vehicles it also tells the injectors when to fire--a guy at the junkyard bet him 20 bucks it was the module,and he replaced it,and it has never failed to start yet,3 months later!--he put a new ignition module in (an AC-Delco from GM)and took a sledge hammer to the old one!....oh,and he paid the 20 bucks to the guy who finally told him what to replace too

 

[dirtwarrior17]

Like i said wd in the wd 40 stands for Water dispersing..... that means you can take an electric drill, stick it in a bucket of wd40 and run it without it shorting out or you getting electricuted... The wd40 is stopping whatever electrical short or problem you have that is being caused by moisture. when the wd wears away it won't run.

 

[s373n_rcr]

Well I did what I should have done two months ago and replaced the ignition control module. Took about 10 minutes and seems to have solved the chronic no-start condition. Apparently these ICM's are notorious for cold failure.