1964 Beetle won't start when engine hot.

[carbjim]

After a run of several miles and the engine is well up to temp, the engine refuses to fire/start up. The 6V battery measures 6.2V while cranking the engine over. New fuel pump, dist overhauled, timing checked, tank fresh gas, and all ignition connections checked. Engine starts again after cooling for a while and runs great.
One more point. Cranking while hot fails to start, I turned the ignition switch on and pushed the car only a few yards, popped the clutch in 1st gear and she fired up quickly and ran great.

What is the temp (heat) doing to cause this problem?? I'm stumped. All inputs greatly appreciated.
Jim Gregory
Laurel, MD
[email protected]

[Ol'fogasaurus]

Can you do a starter draw (voltage) when the engine is cold then do one when the engine is warm. This is only one possibility out of many.

Lee

[ainokea]

2 possibilities, 1 check the ground strap from trans to chassis. Clean up the contact surfaces. This alone can cause a no start because heat causes metal to expand breaking ground until it cools. 2. get a roll of 10 guage electrical wire and comprable connectors.Pull the ignition switch. There will be 3 wires connected to the switch, 10 gauge at #30, 14 gauge at #15/54, another 10 or 12 gauge at #50. #50 wire is the one you want to replace from the ignition switch all the way back to starter terminal #50. A 55 year old wire can in some cases develop resistance and with a hot engine and may need to cool off before a restart. Another hot start problem is the ignition switch #30. That is the ignition power switch and also can contribute to hot start problems, trace that wire to the fuse panel and cut it off at the fuse panel. Next run a 10 gauge wire to the positive terminal on the battery from #30 on the ignition switch This eliminates resistance from ignition power being drawn from the light switch and gives full 6 volt power to the start circuit. 15/54 is power to the coil and doesn't usually become problimatic, but if you want to, you can wrestle with that too.

[carbjim]

You know, the real fact that bothers me the most is that while the engine is still hot ( I mean, less than 5 minutes still sitting in the open hot sun on hot blacktop), is that with a short push of maybe 10 feet I pop the clutch while in gear and the engine comes to life immediately!!! . What is it? Fuel or Spark??
I cranked and cranked the engine over and nothing!! Then this short push.
I measured the bat volt while cranking and it is at 6.2 Volts, surely enough for normal operations so I've eliminated the battery as cause. Stock dist and ignition system.
HELP What am I missing??? After sitting in the garage overnight I can set the choke, just bump the starter and it just jumps to life with a good healthy idle
This has me completely stumped.
All, All inputs are welcomed.
JIm G.

[Ol'fogasaurus]

Jim, my post dealt mostly with the age of the starter: when they get old and tired they can require more OHMs to work so with heat expansion of the starter requiring more draw or wiring things can get iffy. If the brushes of the starter and/or the com needs turned then something similar can happen.

Ainokea went to the next line of direction and it had to deal with wiring; both singularly or together they can cause problems. The first thing is: do you have the flat woven strap that goes from the pan on the right side to the ground on the engine those straps are a pain in the-no-speak-about. American cars finally got rid of them in the late '40s or early '50s and those of us who dealt with them got rid if the quickly once we found out about their short life. They were known to fail for a couple of reasons but they were used mostly as the ground strap. If you have one get rid of the @%$#&% quickly.

The other thing is that wiring gets old and tired especially at the joins. Again, this is a job for the OHM meter. Also remember, the pan can get tired metal wise so the grounds don't often work well. A rule of thumb is that the ground should be the same gauge (and distance) as the hot wire. VW, as I remember, does not protect the lead from the generator/ALT to the dash and back. I fix that in my buggy rewires.

I hope this helps and gets you started in the right direction but there are also many other directions to follow.

Lee

[SCOTTRODS]

You can check the Starter capabilities by putting a starting button on and trying to start once hot... basically a high amperage Push button (momentary switch), with a couple of wires on it with good clamps on each wire... clamp them on the Starter after the solenoid and see if the starter will start the car with the ignition turned on, of course... Safety being important, insure the vehicle is in neutral and no one can change that. Make the cables long enough (Jumper cable style but shorter) to push the button while not under the car if you like.

Your issue sounds a lot like what the "Hard start relay kit" was "invented" for... Except for a lot of bugs wouldn't turn the starter at all. I used to have one under the back seat of my Bugs and if ever one decided to keep me from starting with the key(similar to you issue), Id turn on the ignition to the run position. reach back and knock the back seat bottom up and press my stand by button and crank it right up. This was MY experience on this stuff... Maybe yours will be much easier in the long term.

I've also had similar issues from a bad Condensor on my distributor, and eliminated that problem with Pertronix ignition set up.

Again, these are just a couple more angles to approach with... Most of us have been here before with one of the things we offer up...

[ainokea]

What is not being considered is metal expansion when hot. It is many times a matter of heated metal expanding enough to break ground continuity to the starter. But, if you wait for awhile, the metal cools and retracts, ground is re-established, and starter works again until it gets hot. A simple fix if it's not resistance, is to run at least one 10 gauge wire from the negative battery terminal and hook it up to the bottom mounting stud of the starter with a ring connector under the nut. just clean off any paint at the point of connection.

[carbjim]

First I want to thank all for the sincere advise. What an education for me. My son remembered a similar issue with one of his earlier vehicles and decided to test the coil. Sure enough it was failing under heat. He ohm tested the primary and secondary both at room temp and in engine compartment when hot (his procedure). With new coil installed this old girl is once again ready to go anytime.
Again, thanks to all for sharing your experience and advise.
Jim G.

[Ol'fogasaurus]

Glad you found the problem. I have had coils go but not act like that. My similar problem ended up being the rotor in the dist. As I said, so many ways inanimate objects trick and beat us humans.

Lee

[rrb6699]

the rotor for the distributor contacts or the rotor shaft itself? I assume it's the electrical