[Croz]

Ok, so, i have been having an intermittent starting problem. The car is a 1969 GTO with a 400 motor. Ignition has been swapped to an HEI distributor. The problem i am having is completely at random, the car will turn over and over, and just won't start. I know its getting fuel, and its turning over, so that leaves spark. Also, i have noticed that when it won't start, my tach just sits there not moving at all, but when the car will start the few seconds before it starts, the tach will bounce along with the motor turning over. I don't even have a clue what that means, but it makes me think the problem is in the distributor. Also, when it does start, it runs fine. Hasn't died once, and it seems to have i higher likelihood of starting after it has started, if that makes any sense... I am fed up with the problem, and have been contemplating just replacing the entire distributer as I just want the darn car to run, but I am weary that i am missing something as I would think that if it was a distributor problem, even intermittent, that at some point it would have lost spark while it was running and died. Is this a correct assumption? Is there something I am missing that this indicates could be wrong? (i am probably missing a lot as electrical problems seem to get over my head really fast)

Other related information:
It used to have an msd multi spark box that stopped functioning, and at that time i took a cheaper route and replaced the distributor with one of those all in one jobs. This was about 3 years ago. Since then, the car was running fine (although i wasn't happy with the downgrade from a performance point of view, but the car ran reliably) for 2 years until this current problem started. Nothing was done to the car prior to it having problems. Also, it seems like it has more problems for a few days after rain. But i dunno if that is related or coincidence, as it also seems to have more problems when i really need the car to start, and i doubt it is not starting to spite me. Although i haven't ruled that out completely, lol.

Btw, i am better with the mechanical aspects of a car than the electrical, so feel free to dumb down your answers for the lay person if needed

[cobalt327]

Intermittent ignition problems are some of the hardest things to pin down. Because they come and go, you may end up using a process of elimination to find the underlying problem.

The first thing I'd want to be sure of, is good mechanical contact being made between the terminals and the pins- at all points within the distributor.

There is the power into the HEI. It should be battery voltage- not through the resistor wire that it would have had originally.

The plug to the 12V power into the coil and the tach terminal (located at the coil cover on top of the distributor cap) should be a tight fit, and the terminal should be a good, tight crimp w/solder, preferably.

Inside the distributor, the pick up coil has two small wires to the end of the module. These wires move every time the vacuum advance works, so the wires can break inside the insulation. Their terminal connections to the module need to be secure, tight connections.

The other end of the module has somewhat larger terminals, and they, too, need to be on there tight. The module needs to have a heat transfer compound (sold at Radio shack) to allow it to use the distributor body as a heat sink. This isn't the same thing as silicone dielectric grease.

Under the coil is a carbon piece w/a spring that touches the coil output. That carbon electrode needs to be whole, not burned of broken and the spring should be "springy" and not limp or broken.

There should be silicone dielectric grease under the rubber gasket that insulates the center carbon electrode of the distributor cap, too.

The inside of the cap should be clean and dry.

[Croz]

Thanks for the list of things to check. I had planned on getting into it yesterday but my cat ended up having to go to the vet due to a swollen ear. So I probably won't get to it until hopefully tomorrow and then I will let you know what I find out.

Croz

[poncho62]

Just a thought...but right now, my tach is shorted out. I had to unhook it from the distributer or I get no spark.......Before this, I had an intermittent problem as you did....probably something in the tach moving around......Just a thought, try unhooking the tach

[jon72vega]

Originally Posted by poncho62

Just a thought...but right now, my tach is shorted out. I had to unhook it from the distributer or I get no spark.......Before this, I had an intermittent problem as you did....probably something in the tach moving around......Just a thought, try unhooking the tach

I had the exact same thing happen this spring.
Started out intermittent, then got progressively worse.
It turned out my 25 plus year old tach was slowly dying.
I disconnected the tach trigger wire, & everything was fine.

Jon
http://1972vega.wordpress.com/

[Croz]

Thanks for the input, that gives me some hope that I can get my car back to running. Now if the weather would just give me a clear day... *grumble grumble* Damn rain...

Croz

[beertracker]

[QUOTE=cobalt327]

Under the coil is a carbon piece w/a spring that touches the coil output. That carbon electrode needs to be whole, not burned of broken and the spring should be "springy" and not limp or broken.

Some thing else to check for is to make sure the coil output which touches the carbon electrode must be free of rust. I am having similar problems on my Pontiac 400 and the coil output was caked in rust. Also my spring does not have a carbon electrode. I hope this is not a required part?

BT

[cobalt327]

[QUOTE=beertracker]

Originally Posted by cobalt327

Under the coil is a carbon piece w/a spring that touches the coil output. That carbon electrode needs to be whole, not burned of broken and the spring should be "springy" and not limp or broken.

Some thing else to check for is to make sure the coil output which touches the carbon electrode must be free of rust. I am having similar problems on my Pontiac 400 and the coil output was caked in rust. Also my spring does not have a carbon electrode. I hope this is not a required part?

BT

Shown is the part I was talking about. The carbon piece w/the spring goes into the HEI cap first, followed by the rubber gasket. The rubber gasket gets smeared w/dielectric silicone grease on both sides to help prevent any voltage "leakage".

So, the spring end is to the coil, the carbon end is what touches the rotor.

[Torque454]

Sounds like the pickup in the distributor to me, or the module. An HEI is a dime a dozen. Pick up a used one somewhere and stick it in. The good news is that the HEI ignition is all self contained in the distributor, so pulling out one and sticking in the other should eliminate any wiring or other problems inside the current ignition system. If it doesn't then you just have an intermittent problem with getting power from the ignition switch. Maybe you should check that first. Check for voltage to the BAT terminal on the distributor when the engine wont start. If there is voltage then the problem is in the distributor/cap.