Intermittent no start/no spark.

DeeVeeEight

DeeVeeEight

Fast Pedalphile
Joined
Nov 3, 2008
Messages
2,284
Location
Southern New Jersey, USA
I have one of those pesky come and go problems resulting in a no start condition. I am convinced it is a lack of spark but the problem goes away before I can troubleshoot it.
Here's the scenario:
2 or 3 days back I park the 'Vette in the driveway, it rains pretty good for 24 hrs. The next day the weather is nice so the GF and I decide it would be nice to take a late day cruise. We jump in the 'Vette and I turn the key, it cranks strong but it won't start, normally it starts within 2 to 3 seconds. I pull off the dist. cap and looked inside to see if the rotor is OK, etc. and also checked the wires to the batt. and tach. connections, everything looks fine, so I try starting it again and still no start. The carb. is fine, fuel pressure right on the mark. I figure lets jump in her car and go and I'll work on the 'Vette tomorrow (winds were almost 50 mph yesterday). Today the weather is nice so I go outside, tools in hand ready to poke around and see what I can see. I figure before I touch anything let me try to start her up and BINGO like usual she starts right up (???). Now this same thing happened to me about 2 weeks ago, no start, try it later that same day and it fires right up.
I have a 383 stroker with an aftermarket HEI distributor with an internal coil.

Thanks in advance!
 
Intermittent faults are the hardest to trace, let alone via the forum.
My best advice, next time, see if your getting a full 12v at the dizzy. If no spark then, it's probably the module. If no 12v, start tracing it out.
I would also check the coil for continuity both primary and secondary, and check the rotor for a burn spot. Good luck.:cussing:
 
On any HEI type dizzy, you need see if you have +12 at BOTH the tach and B+ terminals of the cap, that reads across the coil....I have found the crimp tabs on the coils are NOT cleaned from formvar before crimping, I have caught one of them pants down long time ago for that, just heat/solder the crimp connections on the red/wh-yel wires....that is the coil primary....

another thing that can be is a bad/intermittant coil sense unit under the dissy rotor....but being aftermarket, who knows for sure, I talking of stock stuff....

I have seen modules go but not so much with being intermittant, but if aftermarket.....no guess, change it outright, and solder the coil connections....

when the engine cranks....what does the tach do?? say anything?? if so, I would assume something funky in the dizzy/wires function....

:cussing:
 
The simplest first test to see if it is a "no spark" condition is to unplug any plug wire, insert a spare known good spark plug, lay it on the manifold so you have ground and crank it over.

If the dist is working, you will see the plug sparking.
Very easy method, since it requires no tools.
 
010752 said:
The simplest first test to see if it is a "no spark" condition is to unplug any plug wire, insert a spare known good spark plug, lay it on the manifold so you have ground and crank it over.

If the dist is working, you will see the plug sparking.
Very easy method, since it requires no tools.
Click to expand...

I prefer the loosen the boot, hold it just away from the plug/known ground, and get knocked on my ass method. Works best barefoot, or wearing flip flops.
 
big2bird said:
010752 said:
I prefer the loosen the boot, hold it just away from the plug/known ground, and get knocked on my ass method. Works best barefoot, or wearing flip flops.
Click to expand...

Been there, done that. Looked funny as shit when my leg kept getting zapped to the fender (ground) causing involuntary muscle spasms. I banged my knee on the fender 3 or 4 times before I could let go of the wire.:clobbered:
Click to expand...
 
DeeVeeEight said:
big2bird said:
010752 said:
I prefer the loosen the boot, hold it just away from the plug/known ground, and get knocked on my ass method. Works best barefoot, or wearing flip flops.
Click to expand...

Been there, done that. Looked funny as shit when my leg kept getting zapped to the fender (ground) causing involuntary muscle spasms. I banged my knee on the fender 3 or 4 times before I could let go of the wire.:clobbered:
Click to expand...

Pretty sure I already told of this, but a old vette friend from some 40+ years ago, went to pull a plug wire on his running vette engine, it knocked him back into the bushes....so what does he do?? mess with the same wire again, with the SAME result.....we laughing our ASSES off at him, once stupid, fine...but to go REPEAT the damage right away..??:clobbered::devil::bounce::bounce::bounce:
Click to expand...
 
Problem solved

Today I was going to jump in and go for a spin before the rains come.
Yeah, right... just my luck, no start.

I'll cut to the chase.

The rotor was bad. Arcing through the plastic base of the rotor to ground. You could see a little black spot in the plastic from the carbon tracking on the underside of the rotor. It's amazing how at one moment it would not start and then when I would try it a little later it would - and run just fine. You would think that once it found ground that would be the end of it.
The issue that this leads to is that this rotor was replaced about 1000 miles ago, maybe even less. What's the deal with getting a decent replacement part these days? Does anybody have a recommendation for a rotor that will last a few miles longer? HEI dizzy, internal coil, no MSD. (Sounds like I am ordering Chinese food - no MSG please!)
 
Join the club man, had MY fill of shit parts recently enough too....

but not to worry, the green weenies will have us ALL walking before long anyway, no parts for worry over then....

:amazed:
 
DeeVeeEight said:
Today I was going to jump in and go for a spin before the rains come.
Yeah, right... just my luck, no start.

I'll cut to the chase.

The rotor was bad. Arcing through the plastic base of the rotor to ground. You could see a little black spot in the plastic from the carbon tracking on the underside of the rotor. It's amazing how at one moment it would not start and then when I would try it a little later it would - and run just fine. You would think that once it found ground that would be the end of it.
The issue that this leads to is that this rotor was replaced about 1000 miles ago, maybe even less. What's the deal with getting a decent replacement part these days? Does anybody have a recommendation for a rotor that will last a few miles longer? HEI dizzy, internal coil, no MSD. (Sounds like I am ordering Chinese food - no MSG please!)
Click to expand...
A/C Delco tune up parts are best. NAPA is about as good. Neihoff is crapola.
 
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