OK, first I would like to say this will be cross posted, as Cap't Krusty got me for that last year! I recently had the hot start issue visit me at the CVS parking lot. Being ignorant I called AAA, not knowing that I could have waited it out. I have a spare starter and ordered another ignition switch before reading Sir Andy's post describing this, shall I say phenomenon. Another post mentioned there are insulation kits to prevent this. How well do they work? Who sells them? If this is simple and works why not. Has anyone ever ducted a starter e.g. our alternators?? It would be easy to do. It should be easy enough to fab a ducted aluminum cover, if req'd. From the far side, a small CO2 canister ducted to the starter via the rear trunk. Just open the trunk and press the CO2 button for 10-15 sec's and viola. Just a small hole in the trunk for the CO2 discharge hose. Maybe, I don't know. Just thinking out loud here. Beats crawling underneath with a hammer. Let's hear some ideas. Seems like a simple fix but what do I know. I have less than a 1000 miles in a 914.

IIRC - PP sells those 914 insulator pads, but they'd fit VW starters too, so you could probably shop around. I've never tried one personally, so cannot speak to how well they'll work.

http://www.automotion.com/product.asp?pf_i...amp;dept_id=999

There is also a starter relay which AA, PP, PMB, SMC, Pelican, etc. sells, to boost voltage to the starter & give it a little extra uoomf. Haven't tried one myself.

http://www.automotion.com/product.asp?pf_i...mp;dept_id=4745

If you're shy about crawling under with a hammer, then just give 'er a push & jump in when going more than 5 mph or so & pop the clutch into 3rd gear & varoom! ... usually. It helps to park on a down slope.

Unfortunately, with these air-cooled 914s, Porsches & VWs - their Bosch starter is a weak point which goes every so often. My service records back to 1975 show a new/rebuilt starter every few years & "X" 10,000's of miles as long as I was driving it!

However, they usually don't give you problems until the starter is going bad &/or develops what we called a "flat spot" back in the day (which is why the tapping works). So it sounds like it is time for a starter in yours as the first step, as it sounds like you're doing.

http://www.automotion.com/product.asp?pf_i...mp;dept_id=4644

I've listed the PP links to the parts above to give you a start, but you can do your own searching for the others & best prices.

Good Luck!

Cross-posted reply (Actually it feels pretty good to say that again).

I have a suitable starter, but it's certainly not new by any means. WHen I first got my 914 3 years ago I too experienced some hot start issues.

What I did was to buy a sheet of the gold reflector foil that is used in race cars. I covered the starter and solenoid with this, and used metal tie-wraps to secure the foil. Accordingly to the specs, the foil I purchased reduces heat absorption by about a zillion percent. But regardless of the silliness of the specs, I haven't had a heat related problem with my starter since.

I think I paid abnout $40 for the sheet of gold reflector foil, and I used about a quarter of the sheet on the starter.

Besides, it looks cool!!!

Eric

$22 for a $10 ford solenoid.
http://www.automotion.com/product.asp?pf_i...mp;dept_id=4745

Most of the time is a just slight voltage loss and the bosch starter just doesn't click in. I have had a ford solenoid on every AC VW I have every owned, so I never have a hot start issue.

I installed the Ford solenoid and it fires up right away every time.

Actually Bosch was aware of the problem of the solenoid becoming so hot under the car that the resistance became too high and the slight voltage drop between the ignition switch and the starter was enough to not let the solenoid work. The easiest fix is to install the Bosch factory hot start kit. It is quick and easy and cures the problem via a factory kit. (we call it the Bosch apology kit!) It is only about 20 bucks and comes with easy plug in wires in line fuse and bosch relay.

OK, all excellant info, thusfar. But let's narrow it down. I think I read one response naming the starter/solonoid as both being culprits. It's (the solonoid)certainly the logical culprit. Can anyone say if it is one or the other with the "hot start issue"?

I have about 200 of those solenoids and the retail on them was about $6.00. How many would you like?

The bosch starter solenoid needs a minimum 9v to kick it in. The stock wiring often has a loss and by the time it gets to the starter there's not enough juice left to make it kick in.
The Ford solenoid only needs about 3v to make it kick in then it sends a full 12v to the VW starter solenoid and then she works just great.

BTW IMHO the bosch relay kit, which is nothing more than a Karmann Ghia horn relay, is to wimpy for the job.

I'll get one from you at the Bovine Incineration.

A couple of comments... First, the wire from the ignition switch to the starter is a fat yellow one. On the cars with seatbelt interlocks, this wire gets interrupted at the interlock relay, which is under the passenger seat. As memory serves, it arrives and departs said relay with quarter inch fastons. If you're not using your seatbelt interlock, cut the fastons off, strip the two ends, and solder them together. Use shrink or tape to insulate. I believe this is a source of excessive resistance/voltage drop. If you're actually using your interlock, then at least pull the connectors off the relay, polish both up, gently bend the socket (on the wire) so it'll grip tightly, and reinstall.

Second- I had this problem with my 914 back in the 80's, and I installed the Bosch relay kit. There are actually two windings in the solenoid- a pull-in winding, and a hold-in winding. Once the armature is all the way engaged, completing the electrical circuit to the motor itself, it doesn't take as much magnetic force to hold it there as it did to pull it there, and the pull-in winding drops out. The way this happens is that the pull-in winding (more turns, lower current) connects from +12 (arriving from the ignition switch) to the + side of the motor. Thus it is actually grounded through the motor armature itself. The current is limited by the coil to a low enough level that the motor doesn't start up. When the solenoid pulls in, it shorts across this coil, turning it off, and connecting +12 from the battery directly into the motor. You can get tricky and hook the relay up to the pull-in winding only. This way, when the relay drops out, that winding is already out of the circuit, which virtually eliminates contact arcing in the relay. (Contacts are mainly damaged during "break", due to arcing, not during "make".) It will then last "forever". I installed mine maybe in '86 and it hasn't heat-locked since.

I hope this makes some sense. I'll take a picture this weekend of my installation when I'm under there attending to my annual diddle-with-the-backup-light-switch-to-pass-April-inspection ritual.

Jim

Ford relay is a great fix for dirty connections. I used to argue the need for the "patch." But I give. You can't argue with voltage. Either fix it with clean connections, or patch it with a "hot-start" relay.

As for me, I choose clean wiring.

But all due respect to the patchers. They fix lots of other problems in life too.... Can't get it up?? Need a crutch for cigarettes?? Yeah, you get the idea.

See this is what I don't get, you will cut and hack a new wire in, ignition switch or whatever and yet knock this "patcher" who uses a Ford solenoid, who BTW has never ever cut an single OEM wire on his own cars. Ever.

On other cars I've repaired previous PO hacks, built new engine harnesses and made adapters so I didn't have to cut, but my 914 has a flawless harness and it is going to stay that way. I can remove the solenoid faster than I can change a starter, 2 nuts, a couple connectors done. Installs just as fast.

It's a incredibly simple voltage drop issue, all the relay does is boosts that voltage loss back up to 12v.
I did this for a living, I have quite of these "patches" running around. I use to tell customers that I'll mess with their wiring at $65/hr straight time...or you can have a $35 installed solenoid. Also in almost 20 years I only ever had one come back, my wife's winter car, that solenoid failed due to corrosion.


BTW I quit smoking, quit drinking, do a 20K bike ride through the hills every day, I'm the primary home school teacher to my 2 young kids, work on cars, building a chicken coop for my girl, post here and at a few educational blogs and I'm rebuilding my house... not to mention the fact I'm almost 49 and I have a 9" dick that's as hard as a rock.
What did you do today?

Oh and I forgot... I'm also passing a kidney stone, with no drugs, so I can be a bit irritable as of late.

But I'm just a lazy patcher

Just put a 72-up 911 1.5 hp starter vs the .8 hp 914 starter. Get a aftermarket high torque starter. No wiring or cutting issues.

There sure are a lot of different ideas how the solenoid works.
Does anyone have a manual of how the Bosch solenoid really works?
Jim, how does the pull in winding "drop out"? I think you misunderstand the reason for the hold-in winding. I believe it is there to reduce the current load through the ignition switch. I could be wrong tho. Any reference to confirm what is right?
I took some ohm meter readings of the two coils and they are almost identical readings to the solenoid case ( ground , about 1.4 ohms). Hence the solenoid wants to draw about 8-10 amps. That is a lot of current to continually flow through the ignition sw. during the start cycle.
Also heated up the solenoid with a heat gun and the ohmic valus dropped- so as it heats up it wants to draw more current. As voltage goes down and current goes up, at some point the power applied to the electro-magnet will not over come the spring and friction internal to the solenoid.
That is why the remote relay is so effective! It switches 12 volts directly from the battery to the solenoid.
Thanks,
Tom

Not sure why this is such a dilemma? Had the same problem, put in one of those mini starters and haven't had a problem since.

OT: If your rural (i.e. snakes) you might want to get a couple of glass eggs for your coop. And if you can pass those stones w/o drugs, you are one tough sob. I had 'em 3 times.

Pass a hundred or so stones since you were 20 and you'll get used to it....well almost.

I passed one that was 5mmX7mm after litho one time...but I needed lots of drugs for that one....

Maybe just a bit of "Too Much Information"... BTW; If it's been that way for more than four hours, you are advised to contact your doctor...

Just to be clear Mark, no knocking from me at all. My apologies if it came across that way.
I'm not a purist at all and have no problem with anyone doing whatever they want to fix anything, whether that means modifying wiring or adding a relay.
No question the relay works. It's a set and forget solution. I've just found that for me it's an extra widget I don't need because clean connections work without it.

This fix, "fixed vw's that were only a few years old" It is a permanent fix in my opinion. Cleaning and reseating connections is only good for a few years and each time you replug a connector it only gets looser. This experience comes from many years of trouble shooting business machines that are usually in a much drier inviorment. As for cutting and hacking you remove the starter wire from the ignition sw and put it on the relay, then you run a wire from the battery terminal on the starter to the common on the relay, then a wire to the terminal on the solenoid that used to have the ign sw wire on it and thats it, also ground the other side of the relay coil. Two-three new fabricated short wires and a mounted relay. I never used a ford type relay. The type that is used for headlamps is plenty big enough. 30 amps. On the first bugs I just modified a horn relay and it was good enough. Put it by the battery under the seat and ran the wires through the grommet that the battery cable went through. The first one I did was a 58/64 bug sedan that I had converted to 12v in 68. The 12v starter that would work with the 67 1500 bus flywheel was the trick back then.

FWIW, I had hot start issues for years. I fixed them by installing a rebuilt starter, fixing all my charging system grounds and other cabling, and making sure that my charging system (alternator, regulator, and battery) were performing as they should (see www.ratwell.com and the article on the charging system for full procedures). Net result is that despite living in Phoenix and driving my car in 110 deg. F conditions, I've never had a hot start issue since, and my system is does not use a hot start relay.

When I got my car, I went through the electrical system replacing bad connectors and cleaning others. The relay board 12 and 14 pin connectors had a lot of corrosion on the pins. Also completely removed and cleaned the trans ground strap and cleaned the surfaces it connected to. 4 years later, no hot starter issues. A lot of work, but this will put the car back to like new electrically for the start circuit.
Tom