TheSamba.com :: View topic - Temperature determines go, or no-go...

Wed May 04, 2005 11:33 am

I know I've brought this up before, but after struggling with it for a month I can simplify the description. A tune up, valve adjustment and use of starting fluid has made no difference at all.....
In my stock '73 standard bug the engine's ability to start is affected by the ambient outside temperature. The engine being hot or not started in a week makes no difference, wet or dry weather makes no difference.
If it's cool, or below 75 degrees outside then the car kicks right off every time and runs like new.
If it gets above 75 degrees outside then the car will crank and crank and never start. You can spend all day cranking and not get a single sputter.
However if you wait for the ambient temp to dip below 75 degrees again then it'll kick right off without hesitation.
No one has been able to properly anylize this because it makes no sense at all. What the hell is on this engine that can be so totally flipped around by a few degrees of outside temperature??
Love to hear any suggestions. This is driving me crazy!
Thanks!
Tim

Wed May 04, 2005 11:58 am

what are your:
carburetor
-jets
-main
-idle

Distributor
-timing
-dwell

plug wires any good?

Wed May 04, 2005 12:36 pm

Hi Pooter,
Yeah, the wires are fairly new, as is the distributor, timing is dead on and it's got electrontic module in place of points.
As for the carb, even if I spray starting fluid down the throat it still won't even hiccup. On my old GM cars I at least got a backfire out of them with starting fluid even if the carbs were shot.
I swear I think I can hear the car giggling behind my back. :twisted:
Tim

Wed May 04, 2005 12:43 pm

One more thing, every once in a greaaaat while while cranking it I'll get a brief stutter as I'm realeasing the key. I heard a suggestion (mostly for 6 volt cars) that it may be losing too much current through the starter. This weekend I'm going to try replacing my battery cables, cleaning cable connections and getting new coil wire to see if it makes a difference.
Tim

Wed May 04, 2005 1:34 pm

Might be the choke adjustment.

Max

Wed May 04, 2005 1:53 pm

I am certainly no air cooled mechanic, but have played with cars for over 20 years. I would try a different coil and/or try putting the points back in. Also could be an intermittant ground or hot wire on your ignition. Just my .02 worth!

Wed May 04, 2005 2:01 pm

Thanks Max and Urban,
Those things sound very plausable and are worth a look. I'll put them on my list of things to check!
Tim

Wed May 04, 2005 3:11 pm

vw66 wrote: One more thing, every once in a greaaaat while while cranking it I'll get a brief stutter as I'm realeasing the key.
Tim

I'd be interested in this answer. My car starts only when you release the key. Been like that since I had it (3 years).

Wed May 04, 2005 4:20 pm

When it won't start are you getting spark at the plugs? I suspect some sort of ignition problem.

Wed May 04, 2005 5:29 pm

my car was acting very wierd also . one night i saw a tiny blue light comeung form under the dash. i looked all my fuse's were ok . tryed to start agian and nothing . saw the light again , pulled the fuses out and one had been shorting out for a wile im guessing because the fuse was good but the op termanal was melted down into the plastic part of the fuse makeing the fuse 2 short , bump the car right and she'd start bump again and bang dead. i chased this problem for 2 moths buying every part i came across. i hope this might help

Wed May 04, 2005 5:50 pm

OK I will take my shot at a Wild Ass Guess.

Distributor cap with a crack in it, or on the coil tower.

My backup guess is that there is moisture inside the cap.

Wed May 04, 2005 6:55 pm

Air-Cooled Head wrote: vw66 wrote: One more thing, every once in a greaaaat while while cranking it I'll get a brief stutter as I'm realeasing the key.
Tim

I'd be interested in this answer. My car starts only when you release the key. Been like that since I had it (3 years).

Hi Volks,
Both of you get a multimeter and check for voltage drops through the system. When you release the ignition switch the engine is still turning and when the switch clicks back it hits a cleaner, less worn part of the ignition switch or just because the starter is not drawing so much voltage and the coil finally gets enough voltage to spark stongly..... BTDT!
Eric&Barb

Wed May 04, 2005 8:07 pm

Air-Cooled Head wrote: vw66 wrote: One more thing, every once in a greaaaat while while cranking it I'll get a brief stutter as I'm realeasing the key.
Tim

I'd be interested in this answer. My car starts only when you release the key. Been like that since I had it (3 years).

most likely the electrical portion of the ignition switch is bad....i had this problem for years on a 74 bug...finally put a testlight on the coil and the light would come on with the key, then out when turned to the start position....my car would also "fire" when the key was released from the start position....

Wed May 04, 2005 10:14 pm

Sounds like you ain't getting any spark, check to see if the coil is getting power, the distributor is getting power, and the plugs are getting power.

Sat May 07, 2005 10:33 am

Hey guys, thanks for all the input!
It has changed habits again and is now starting only after the key is released and it is doing it consistently now. I checked the coil, cap, and rotor and all look dry and fine. The ignition switch went out about 3 months ago so it is new, but it could just be faulty. Time to start tracing down possible sources of resistance since apparently the old bugger isn't getting enough, if any, juice to the ignition system while the starter is cranking.
I'll let you know what I find.
Tim

Tue May 17, 2005 10:21 am

I finally gave up and took it to the shop. Turns out of all things that my fairly new ignition switch was faulty and not making good contact, hence the irratic occurrence of the problem. The original switch lasted 35 years, and the replacement lasted 6, no, 3 months! Crazy!
Just wanted to thank everyone for their help!
Tim

Tue May 17, 2005 11:53 am

Air-Cooled Head wrote: vw66 wrote: One more thing, every once in a greaaaat while while cranking it I'll get a brief stutter as I'm realeasing the key.
Tim

I'd be interested in this answer. My car starts only when you release the key. Been like that since I had it (3 years).

Heh, I had the same problem about a year ago. New ignition switch fixed that.

Tue May 17, 2005 2:08 pm

Yeah, the guy at the shop said the replacement ignition switches are crap compared to the originals so there's a shorter life and a greater likelyhood of getting a bad one. And it's apparently the first thing they check when a car coughs or starts on releasing the key. I learn something old every day! :wink:
Tim