Intermittent starting issue

[Muddytazz]

Turn the key and it will crank over all day long, just won't fire. Doesn't do this all the time either. Some days it will fire every time, some days it won't. And its not just a day by day issue, it can and does sometimes change by the hour. I've ruled out the module in the dist as it either is or isn't working, ruled out the coil(took the one out of my burb and put it in my dads and the issue was still there). Only thing I haven't looked at yet is cap/rotor and ignition switch. Could it be one of those or something completely different?

 

[diesel4me]

EFI or carb??

If yours has EFI,it could be a faulty oil pressure switch,not allowing the fuel pump to energize sometimes when you turn on the key..if its a carbed rig,you'll have to find out if its spark or fuel your lacking next time she wont kick..check for any codes??

 

[greg mgm]

Is this on your 75 sub? My 78 PU did exactly the same thing, very frustrating. After changing the dist module, it fired right up. Maybe yours will do the same???

 

[dyeager535]

Don't count the module out. It isn't a work/don't work piece, same as most things electrical.

 

[Muddytazz]

This is in a 77 carb'ed burb....i know its not fuel problems cause you can smell it lol, its definitely electrical

 

[79Beast]

I've had the same problem on my '79 pickup. For me, it's always spark that's lacking when it won't start. I always have power to the coil and I've installed several new coils and ignition modules as well as the capacitor and related wiring. It still does it. I bought a new distributor from Summit, but I've been to busy with other things to put it in (lazy). Near as I can figure, there is either an intermittent open or intermittent short somewhere inside the distributor. 99% of the time, if it doesn't start I tap on the top of the dist cap with my pocket knife and when I get back in the truck, it will fire right off.

 

[diesel4me]

Bad ground to the coil....

I've seen the ground strap to the coil get all corroded and rusty --its a peice of steel thats twisted and has a "hook" on one end where one of the hold down crews go thru it...no ground = no spark,and it can come and go,changes in temparature can even cause it to lose ground..take out the coil and this "strap" and shine it up with some sandpaper..might help..

90% of all my "no spark" problems were the module on the older carbed trucks I've owned..or bad wires from corrosion and old age..one truck drove me nuts--it dies,I put in a good used module,it starts right up again--runs great for weeks..Then,it wont restart after stalling again!--no spark!

Put another used module in it--it fired up,but I had to crank it forever...it started hard for a few days,then it fired right up like normal for a few days--then it craps out again in my driveway-thinking my "good used module" might have crapped out,I bought and installed a new pick up coil,module, and ignition coil,installed them --now it wont start AT ALL!...NO SPARK!--WTF!!

..... In desparation I throw in a complete used distributor,and it fires right up!...SO--one of the "new"parts I got were defective,right??...NOPE!--turns out the wires that go thru the base of the distibutor that connect the pickup up coil and module to the distibutor cap were broken in one spot,like they got stretched until they broke,and were barely touching--after they got hot they evidently moved apart,breaking the connection!--you could feel a "mushy" spot in the insulation where the wires were seperated--had to slice it open with a razor blade to confirm my suspicions...10 bucks and a new "harness" for the distributor later,it ran like a charm again!--and no longer had that strange "misfire" and hesitation it always had in the past..