The death of a 1000 cuts

[rdane]

That is about how this feels I am sure

Part of this story has been seen before but it is still ongoing so I am looking for new ideas.

First indication was the car failed to restart after topping off at a a gas station in the first 1/4 of a 600 mile run. Had me concerned as I pushed the car past the pumps, pop the lid and thought to hit the starter again and it fired right up. As it did for the rest of the day.

Second time, car is in for wheel bearings and an oil change. Long trip coming up so I ask for a look around and a general maintance check. Car is dead across the board one morning. No lights, dash or ignition. That is traced to fused wiring from an old alarm I removed. The section is rewired.

Third time I drive it a couple of miles, it barely gets warmed up and I run in to grab the mail. I return and zippo....ignition but no start up.

Don't smell gas but the crank sounds slightly funny. A slight cough but no fire. Easy to tell something isn't right. Car gets towed to my wrench. Drop it off the flat bed and just have to hit the ignition...fires right up. Can't believe it. Drive around the block and turn it off...fires right up again. Come back after lunch to drive newly possessed, devil car home...no start up again...WTF! Leave it at wrench's over the weekend. Think this aint right so I take some tools and go in on Sunday...again the thing fires right up. I drive it around the block for 30/45 minutes and bring it back. Turn it off and it fires right up again.

Not trusting the newly possessed car I leave it for smarter people than I to look at. It fires up and runs for the wrench...they clean the CD box and check the wring. They are at a loss...car is running and starting.

CD box wasn't emitting much of a whine, fuel pump is 2 years old and humming away. After cleaning, the CD box has the high pitched hum I remembered but I suspect still not as loud as it was before the engine was last out and rebuilt....3000 miles ago now.

Remember that at 2000 miles I find the coil laying in the bottom of the engine compartment when I go to check the oil. No harm, no foul I turn the engine off and remount the original, 190 mile coil back to the fan. I buy a spare that now sits in the shop.

I drive the car home......catch a stone and break a new windshield...car is possessed I tell you!

Park the car, discussed.
A week later I take the car to get the windshield repaired. Driving 6 miles slowly to get the car warmed up for the great drive I'll have with a new windscreen and working CD. Get the estimate, sign the paper work and go back to pull my car around to the bay. You guessed it, car won't start. I check the fuel pump.....humming away. I check the CD box and wiring...looks good and high pitched whine is there. I check the fuses. I try holy water....nothing.
40 minutes later I call triple A..."same 911 as last week? To the same shop?" A little terse..."yes", like I have more than one 70k$ '79 SC, moron.

At the shop.....and off the truck...devil is just ****ing with me...of course the car fires right up. All week long car has fired up first thing in the morning and every time the wrench checks it, yep fires right up. Having no time to drive in the last 4 weeks and now this, being unable to drive, as a week of vacation starts I am thinking I'll just burn the car and be done with it. May be there was something to burning witches at the stake in Salem...it may just be easier than actually having to live with this ****. It isn't a Porsche any more after 200K reliable miles, it is a possessed money pit.

Sorry about the long post but I wanted to get the details out. PLEASE ,someone, tell me what I have missed.

How do you find a problem you can't duplicate on demand?
Car runs great by the way...when it runs.

[ronin]

process of elimination. one by one repair or replace any possible source of electrical malfunction in the wiring to assure that it's all getting electrons in the first place, then move on to the solid state stuff, etc. btw: Ed's doing a bang-up job of tracking it down

[MichiganMat]

Bummer dood.
this isn't a hot-start issue is it?
If all else fails, put in an MSD system and coil and drop the CDI

[Danskman]

Ignition switch? They can become intermittent before completely crapping out.

[rickeolis]

Many older Porsche electrical problems have been solved on this board by installing a new ground strap from the body to the starter.
Give it a thought...

[Ho Hum 74]

I also have pain...but let's talk about yours:

Sometimes hot start issues can be because the starter gets too hot and then the car will not start. This can be because your heat from the heat exchangers may be blowing on the starter. Have you checked the heater hose on the RHS of the car? This is right next to the starter.

Mine had a few hot start issues and this solved it.

I hope you can work it out. I also feel like burning mine right now, I just missed a DE today because of an oil leak. It's possessed I swear!

Tristan

[jpnovak]

I had similar symptoms of bad hot start.

When the CD whines do you have any spark? I would suspect no ouput from the CDI when hot, a intermittant coil (You can check winding resistance hot and cold) or a bad trigger wire from the dist.

If there is no spark when it doesn't start, pull the tabbed connection by the dist and look for the trigger signal. Trace this to the CDI, then look for an output signal from the CDI and find that at the coil. Process of elimination.

[RANDY P]

Leave it with the wrench till it breaks, only thing left to do...Don't take it back till he gets stuck a few times.

Trigger wire off distributor? if it's the original CDI maybe it's getting tired, issue may be heat related. Seems to be a lot of dead CDI's as the weather gets warmer. Sure the wrench has thought of this already though. Only way to know for sure is checking for spark as it's having a fit. Pack a big screwdriver and an assistant next time it gets stupid on you.

Good luck.

rjp



rjp

[rdane]

Not a hot start issue I wouldn't think from the different situations I had problems in. Ground strap is new but good idea. Ignition switch is an idea but if they crank, aren't they good? How is the juice ran...to the starter and to the ignition on separate leads? So the starter could be cranking over but no juice going to the CD box?

I am almost clueless here but won't be before I have to call AAA again. Thanks for the help guys.

[ronin]

nope. not a hot start issue. not a starter switch issue when the engine cranks. starter switch might have been an additional issue when the car was "dead across the board," but that will manifest by itself later if it indeed is a problem

[Shuie]

Is the ground for the CD box good? Broken trigger wire? I know the guys went through the CD wiring, but Im stumped.

Remember that at 2000 miles I find the coil laying in the bottom of the engine compartment when I go to check the oil. No harm, no foul I turn the engine off and remount the original, 190 mile coil back to the fan. I buy a spare that now sits in the shop.

Is that wiring still intact? Have you tried the spare coil?

[1982911sc]

I know this sounds weird, but what about Vapor Lock? I had a Ford Escort that would do the exact same thing.....it usually happens during hot weather. If a hot engine won't start, all you can do is let it sit and cool off. Switching brands of gasoline may also help. Just a thought!

[82SC]

i had that happen to me when I first bought my SC...

Tony Callas (very reputable wrench) worked on it for 1 week and could not figure it out...he also didn't charge me full labor cuz he hated to give me a car that he could not figure out what was the problem...in the end the car ran fine...

I think he endud up taking apart most of the CIS system checking the fuel distributor, and going over the entire engine wiring harness....

I would guess it is an old wiring connection somewhere...that jsut gets jangled into place just so often to make you go crazy....

MJ

[Rufblackbird]

my wild guess would be transmission ground strap?

[john walker's workshop]

it's either fuel or ignition obviously. next time it happens, turn on the key, remove the air filter and reach in and momentarily lift the sensor plate arm. it will either have no pressure on it, or you will detect a pound or so of pressure and hear the injectors whirring. if there's nothing, check the pump relay and fuse. the relay is the rear one on the front fuse panel, and the fuse is the 6th one from the rear. check the wiring on either side of the fuse. it gets burnt and crusty, as does the fuse board. the relay pins can overheat and melt the rubber surrounding the pin holes, and the molten rubber will sweat into the pin holes and create a bad connection.
a spark check is done by removing the coil wire from the center of the cap and holding it 1/4" away from the edge of the fan housing, and then have someone crank the key for a few seconds. in a pinch, you could also wedge it somewhere, creating a 1/4" gap at the end and when you're cranking the key, listen for a snapping sound.

[jwetering]

Ignition switch is an idea but if they crank, aren't they good?

whoa whoa - slow down there. My car is currently not turning *off* when I turn the key, although the gauges go dead, and the fuel pump turns off etc..

My wrench thinks for sure that the ignition switch is worn (new ones are cheap cheap cheap). If you take a look at that bad boy you'll see nearly a dozen wires at the back. Each "pole" does something different, and one almost certainly powers your coil. That said, you do hear the CD box whine, but my point is that the switch may crank the motor but still not let your car start.

Good luck anyway, it sounds real frustrating.

[Rondinone]

My car does this occasionally, and I'm sure that it's vapor lock or a bad accumulator. The sensor plate trick mentioned by jw always works.

[HarryD]

While this story is related to my long departed '79 Triumph Spitfire (think Lucas... Prince of Darkness), the symptons sound vaugely familiar.

My Spitfire would intermittently die on the road. I would crank and get no spark. I would push or get it towed home and 20 minutes later, voila! it started right up as if nothing happened. As this got more frequent, I finally decided to chase down the source. As I said, I verified no spark (see John Walker's post) and then did a bit of trouble shooting with my voltmeter. I found power to the CDI system (in the base of my distributor ) but no output. I verified the points opening and closing etc. Thinking the CDI Unit may be going bad due to overheating, I bought a can of spray coolant from Radio shack, and the next time it died, I walked out, sprayed the electronics until they were nice and frosty and started the car. It started right up. I repeated this several times to verify my diagnosis and went to my friendly Triump parts guy to get a new CDI. He laughed and told me that if I really wanted one, he would sell it to me for $$$ but it would be no better than the one I replaced, or, I could buy an aftermarket unit for 1/4 of the price, move the electronics away from the engine and have a more robust ignition plus eliminate my points. As old Ben Grimm used to say, 'nuff said and I ordered one.

Maybe this will help. Good luck and work slowly to isolate the source by verifying each step is ok.

[Zeke]

I'm betting on the key switch. It does have a few circuits in it, not just the yellow starter wire. I just drove up to get some lumber in my truck, paid, went out to the parking lot to pull into the yard and no spark. I just got there 10 minutes before.

Yes, it's maddening. Just got the damn thing off the flatbed and thought I'd come in and get absorbed here. The truck can wait 'till the morn.

[Evans, Marv]

I had a similar problem with my '72. It turned out to be the ground wire on the coil. I tried everything & it finally boiled down the that simple thing. Like a couple of the guys said, I'd also change the tranny ground strap.