When it is pretty hot outside and I run the car for awhile and then park it for a short time, it won't start when I get back. I have to sit around and let the engine cool a little and then she starts right up. The car isn't overheating, but this gets really frustrating. I was told a while back about something that could be made to put in place of the relay and the car would start right up. I can't remember the specifics. If anyone has any ideas I would appreciate them.

Thanks,

 

Sounds like it could definately be the starter solenoid?
I haven't been down that path with a Porsche yet but I had a truck that did exactly the same thing. As soon as everything got hot, the starter would drain the amperage from the battery if you tried restarting it.
Another thing to do is the basic electrical maintenance. Wally had emailed me that procedure before. Maybe he would be kind enough to post you on it. All about cleanups of terminals, etc.

Cheers

 

Get an old headlamp bulb with one good filament, and make a tester out of it. This tester will pull several amps current, and will show you if you have a bad connection that is allow voltage thru, but cutting the amperage down too far. Put the test light on a good 12 vdc source so as to see how bright it is.

Use the tester on the yellow wire on terminal O5 on the plugs at the bottom of the fuse panel. Plugs start with A on the left, and there is no I plug.

If the tester is not fully bright on this terminal, the problem may be in relay XV or the bridge that is installed in its place.

If you get full brightness on O5, check the yellow wire in the mess of wiring at the jump start terminal. You might want to disconnect the battery ground and disassemble and clean the connections here.

If the plastic cover is missing from over the connections, water from the hood edge will run in and cause corrosion and LOTS of problems.

The key is to get full votage and amperage on the yellow wire all the way to the starter solenoid.

 

Brian,
More information please - is this a CIS car? Is it cranking but not catching, or not cranking at all. The previous two posts assume its not even cranking, or not well. If it is CIS (79 should be?), may be you have a rest pressure problem - pump check valve, accumulator failed, etc giving you a vapour lock from heat soak.
jp

 

I appreciate everyones help. When the car is cold it starts fine. Then I went to a gas station, shut it off, went inside, came back out and it was dead, didn't crank or anything. <img src="graemlins/crying.gif" border="0" alt="[crying]" /> I was really glad I wasn't at a pump. I opened the hood and waited about 15 minutes. Then I got back in and it started right up. No problem at all. Oh, and it is CIS.

Thanks,

 

I had the exact same thing with my other car. It turned out to be the starter relay. Check for current when starting. If it has current, relay is faulty.

 

Ah yes, the classic starter failure when hot. I feel your pain Brian.

I had the same problem when I bought my '79 auto - I used to dread walking out to the parking lot while running errands, wondering if the car would start or leave me stranded for an hour until it cooled down.

The PO had tried to overcome this problem by installing some bypass wiring on the ignition circuit with an overide starter button. It worked only once in awhile.

I tried everything to fix this, from cleaning all connections including the hotpoint multiplug, replacing the starter relay, replacing the ignition switch, replacing the starter motor and battery, replacing the starter wiring connectors - all to no avail.

I finally installed an intermediate relay and removed that funky wiring installed by the PO. My car now starts every time - even on a 100+ degree summer day - since I installed this a couple years ago.

Awhile ago I created a writeup documenting that fix:

<a href="http://ourworld.compuserve.com/homepages/nichols/hotstart.jpg" target="_blank">http://ourworld.compuserve.com/homepages/nichols/hotstart.jpg</a>

Perhaps you may have just a faulty starter motor or starter relay, but I'm betting you have the same problem I did.

Let us know how it turns out.

 

I also had the same hot start problem and the solenoid fix solved my problem completely. If you call NAPA autoparts they will need the part # MPEST81SB to find it in their computer but if you use the napaonline website you can search for ST81SB and avoid the counter guys for $7.99 + shipping.

 

Any progress on this Hai?

Just wonderin'...