I just pulled my 72 out of storage. It was stored with a full tank, sta-bil in it and fogged before putting her to bed for the winter.
It fired up on the first crank and ran well for about 2 miles. It was a very hot day...about 85, then, it started skipping badly and would not idle and quit on me at about 20 mph. I cranked a number of times and about 15 minutes later and it eventually fired up and ran enough (very rough) to get home. I assumed vapor lock, hot day issues, etc. although temp was about 210 on gauge.

It is a few days later and It now will not sart and misfires badly or does not fire at all.

I have checked and it is getting gas to the carb just fine, so that seems ok. I pulled a plug wire and had my son crank it over and spark jumped. I put the plug wire back on and it fired up and ran for about 10 seconds and same issues...cut right out. I pulled a plug wire again and this time no spark jump (used paper clip both times) It appears I have a spark issue?

I checked cap...seems fine, no corrosion, etc. Rotor did have some carbon and I cleaned up with emery cloth. I still have sporadic spark from what I can tell. It appears I have either a coil or a condensor problem?

Help!!! Any thoughts on next steps?


If garage ghost is out there, I want to catch up with you and have you look over my vette for help on a few other issues and compare notes.

Thanks.

 

did you hook up a dwell meter while cranking to see if it is set for 30 degrees? Do the points look burnt?

 

Could be that the carb float is stuck in the UP position so fuel is staying cut off. Also, could have a clogged up fuel filter or fuel tank strainer 'sock'.

 

It is spraying fuel to the carb OK. I'm not sure how to check if the choke is stuck though, it appears to be moving freely.

I do not have a way to check any electrical component.....sorry, no dwell meter. Any other thoughts? I know that some of the time that my son cranked the engine over, it would not throw a spark to the plug over about a 1/4 to 1/2 inch gap, so I am looking more towards a spark issue.

The dist cap looked fine, just a little carbon/burned look to the rotor which I took off easily with emery cloth.

The coil was quite warm when the car had been parked for a while and had not been run for many hours. a short or snother issue....problem here maybe?

 

you have to eliminate the basics and that means are the points correctly adjusted and not burnt? Thus you need a dwell meter and have to check the condition of the points. Once that is established you can go on and swap in another coil assuming you check the + terminal on the coil to make sure you have current both in the cranking position of the key and also the run position.

 

From the symptoms you described it kind of sounds like moisture/condensation formed under the distributor cap after the engine warmed up.
When you pulled the cap did you notice any sweat or water droplets around the terminals?
That could cause a lot of misfiring or intermittent spark.

 

I had the same problem a week ago. A new fuel filter from NAPA cured my problem

 

Could be the coil , but try this real quick. At your coil + terminal you should have 2 wires plus another wire from a capacitor,move the capacitor wire from the pos term to the neg terminal and see if that gives you solid spark. If so replace the capacitor in the dist (and move the capacitor wire back from neg to pos at the coil).

 

The issue you describe here is not specific to Corvettes or even GM cars. Pick up any book on basic ignition mechanics that deals with a points and condenser system and off you go. It's not complicated.

 

My wire at the capacitor is about 2 inches too short to reach the other terminal on the coil.......

I did find a fuel filter that was quite dirty and have a new one installed. However, during the install a bad kink in the fuel line from the previus owner became a leak (my fault) and I have a fuel line on order. I also ordered a points, rotor and condensor tune up set, so I hopefully have everything covered when the gas line comes and I can try it again.

Thanks for the help and ideas. I am dead in the water until the gas line comes in. I picked up a set of flare wrenches and a vacuum tester as I have a vac problem with my lights I need to trace down. I sure hope I get all problems resolved before the summer is gone!

Brent

 

My problem ended up being the capacitor in the distributor. Garage ghost came by on Sunday and was very helpful with his advice. I tried one of his suggestions and had it running soon after he left. My father's day could not be better when I took my wife for a spin grinning from ear to ear. What an awesome guy and a great group of people on line to help. It makes having a Vette even that much more of a pleasure.

Forever grateful,
Brent

 

Any time...My pleasure.

 

You might want to find a capacitor with a longer wire for your coil,it could save you next time your out on a long lonely stretch of highway at night.

Glad you got it fixed.



Thumbs up to Garage Ghost for assisting you.