Seller just accepted my offer...

1975 Malaga Red 2.0...

Only has one problem...

The owner says that when he takes the car on long trips, or does any real hard driving to get the engine good and hot, that if he shuts it off, when he goes to restart it, the starter won't turn -- for about an hour until it cools down.

He says that there is no voltage loss at the solenoid and he does not believe the problem is caused by a relay.

Has anyone ever experienced this type of problem?

What was the remedy? Any advice will help.

I will take delivery of the car sometime next week. I plan on making this one of the first things I tackle.

attached is a pic of my new 914

here's a pic

The 70 used to do that. Had to park it on a hill. (hard to do when your on the prairies). No trany ground strap. New strap, problem solved.

Very common to have the hot-start problem. Check to see that the fuel pump is mounted up front (near the gas tank) and not near the engine bay. That should help you out. Others will chime in on other fixes...not a big issue. Great looking car.

75 should have a front mounted pump from the factory

could be ignition switch

Its ground. Almost positive. Either buy a new ground or get like a 7 foot very thick plastic coated ground strap and run it from the starter bolt to the body. It will very much increase your starting power.

I have more detailed instructions somewhere.. but thats in essence what you need to do.

90% of the time, thats the problem.

Andrew

Well, I had this problem once before also, it turned out to be the CHT sensor. You may want to check that too. In any event, it doesnt sound like that big of a deal. Good luck with it and enjoy it.

I don't think the CHT issue is a long term problem (i.e., happens after a long time). I think it manifests itself after 5-10 minutes.

The CHT is really just an enrichment device when cold, no?

I would look into the ground issues.

Also consider other areas where heat may cause something to expand and lose contact, or to expand and short.

My '73 does exactly the same thing. I suspect a ground problem or bad ignition switch. I have a cutoff switch on the ground side of the battery and suspect that it may be a contributor. I added a wire from the solenoid into the engine compartment so I can bypass the ignition switch. Have not had the hot problem since adding this wire so cannot yet say that I have a bad ignition switch. I read somewhere that the contacts in the ignition switches arc and over time can create resistance.

Problem with this type of problem is that you have to drive hard on a hot day to make it appear. And then again maybe that isn't too much of a problem.

-Jeff

Some of you guys aren't reading the problem. He says the starter won't turn, not the car cranks but won't start. Therefore, this isn't a CHT or vapor lock problem.

It could very well be a ground issue. It could also be a bad starter, or a bad solenoid. I've seen both fail when hot, but work when they cool off. Clean the ground strap connections, if there is one. If that doesn't fix it, fit a rebuilt starter.

did I misunderstand...?
why are we ruling out the solinoid?

I took "no voltage loss at the solinoid" to mean that the power to the solinoid is fine... and there is no voltage loss at the WIRE.

ben, when its acting up in this way did Jon clarify if the starter turns over or just clicks?

nice car..
seriously happy for you
brant

From what I understand, I have (yet to) not experienced the problem first hand, is that the starter solenoid kicks, but the motor won't spin.

Jon believes that the starter may be heating up TOO much and expanding against the housing, preventing the motor from turning. Only after cool down and contraction is it able to work again.

Had not heard the ground theory before.

Thanks Brant, I'm stoked. It's a peach!

Ben

starter is slowly going bad. hot-start relay might help for a while but you're better off investing in a new (or rebuild) starter.

mine did the same, i just bought a brand new high torque starter and it works great now ...

Andy

I would replace the starter and solinoid with a high toqure starter!

I had the same problem and when I cleaned out the solinoid and put it back together it would work for a while then lock up again. I ended up puting a used solinoid and starter in and it worked fine!

Jeff

First of all, I missed some detail here I guess. That sure looks like Jon K.'s 914. I didn't know he was even selling his car. Let alone that you bought it. But congrats!

You've got the common, dreaded, "hot start problem". Clean all of the ground points first. Because that could still be what it is despite the fact that you have voltage at the solenoid. If that doesn't cure it, a new stock starter, or a new 911 starter probably will. As others have suggested, you can do the Ford relay thing OR a high torque starter. The latter would almost certainly cure the problem and would be my choice.

I'd ask for pics of the car, but I might actually have more pics of that car than you do. Nobody ever tells me 'nothin.

Ground it. If that doesn't work. Change the starter. Nice looking car, great score!

If you're feeling cheap, here's what we used to do with VW vans that had a problem that sounds just like yours. Since they are similar Bosh starters, I would guess they could have the same wear issues inside.

Pull the solenoid off the starter, rotate the plunger 180 degrees, clean and grease it lightly and put it back in. Good for another 100K miles. Only takes 15 minutes if you've done it 50 times before.
In the VW bus case, what happens is that the plunger vibrating on the edge of its' case rubs a notch that makes it hard to pull in. When the copper wire in the solenoid gets hot, it draws less current and has less pull so it would first show up when hot. Rotating the plunger moved the notch to the top where it didn't cause a problem.

Oh yeah, if banging on the solenoid with a hammer makes it work on the next start attempt then this is probably the problem.

Of course, your grounds should be good too. Most hot crank issues are a combination of problems adding up, so it could be a combination of connections, grounds, start switch and worn plunger.
hth,

I made a 2k road trip in my 914 with a new(rebuilt)bosch starter.

Every time I would stop I had to let the starter cool off before it would crank.
I even tried to bridge the solenoid with a screwdriver but still no effect.

I cleaned all connections and had the same results with longer drives.

My final thoughts were the electrical connections associated with the starter were overheating and causing a ground or malfunction.

I think the 911 or hi torque starters would probably be less suited to overheating than the stock ones but i have no actual experience with the other starters .

i do. well worth the investement ...

Solenoid....get a Big Fargin Hammer (BFH) and "tap" it....then pull the solenoid when ya get home and lube the sucker....or replace it.

The BFH is for throwing later and getting out yer agressions....