'76 Targa 911S just cut off while driving...

hello recession-fighters...

I was reading old_skul's thread about the engine cutting out on him, when - voila! - my '76 Targa 911S did the same a few days ago...

while driving through an intersection i was thrown into my seatbelt a bit when my engine just died in second gear at about 3000RPM...trying to restart failed at first...i pushed the car to the side, got in, cranked again, and she started up again...

the two days after that she ran fine again, although i experienced two or three ever so quick cut off's while driving...those really only lasted for a fraction of a second...so while i probably should have gone into a service checkup right then, i didn't...

tonight i was on my way to my B-day dinner meeting about a dozen friends, i came off the freeway, slowed down to stop for the upcoming red-light, and this time she stalled while in first, and stopped...i cranked once, twice, (three times a lady), and no luck this time...pushed the car to the side again...cranked another few times, but no-go...on the first two i instinctually pumped the gas pedal, which might not have been the best thing to do...a bit of smell of gas probably came from that...

weird thing was that a few times the engine would not fire at all while cranking, but would fire and turn over a few times after the key went into the OFF position...

i called a tow truck, and waited for almost an hour (they were busy towing cars that essentially work, but are parked in inconvenient places), and decided that i'd risk being ticketed in favor of spending time with my friends...

when i returned two hours later i decided to try again before calling the truck again...first and second tries were bad again, third turned over a couple of times, fourth started and died, fifth was a success and she ran like a sowing machine again...smooth...

drove 20 miles home as usual...a lady-friend followed just to make sure that i wouldn't stall again (wink, wink, oy, oy), and other than one of those half second stalls toward the end, she ran great.

if you hung in this long reading this, you can hang just a little longer...

thing is: i am just as silly as old_skul (i feel for you man!) ...left my Targa Top for restauration at a local shop, and when the weekend came up and it was a 50-50 chance of rain, i went for it...just had to do it...sue me...so it rained, and before i could make it back home there was a puddle in my foot departments.

i have questions:

- what could have happened here?
- do i have a DME and what is it?
- is there anything in the '76 that could also have gone too wet?

i just had my fuel ditributor, cold-start valve, ignition-wires, sparks, injectors, and alternator replaced with new parts, so i don't think they would have anything to do with it?

what's going on? what should i say when i ask a mechanic for help?

now i must sleep...

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1976 911S Targa

[This message has been edited by Till Krueger (edited 02-24-2000).]

[This message has been edited by Till Krueger (edited 02-24-2000).]

No, your car doesn't have a DME in it, or anything elctrical that could get wet with the floorboards. Everything associated with the ignition is in the engine compartment, that is: coil, CDI-box, and distributor. My thoughts immediately lead to the distributor, and the point plate, or its' ground lead, a flexible bare copper lead, resistance welded to the rotating plate that is moved by the vacuum diaphram. I have had them break loose at that spot weld. The CDI-unit could be having problems because of a loose ground connection, or the 'coil' (actually called a transformer in the CDI system) for the same reason!

A trip to the mechanic seems in order to me. He should be able to tell whether anything is amiss with the distributor. A fuel pump relay problem is also a possibility, or a partly-clogged fuel filter problem. If you know what the fuel pump 'whiring' sounds like before you hit the 'start' position on the key, it should be running at ALL times when the ignition is turned on! So, the next time your car stalls, try to ascertain whether the fuel pump is running at that particular time ... it could be important! I believe in your car the fuel pump relay is the same 'round' type as the horn and headlamp relays, so, if you find your owner's manual, it should identify the location of the different relays, and you may want to put a paper tag on the fuel pump and horn relays for a quick substitution if you find the fuel pump not running in the furure. I would suggest a spare relay is a good idea, along with your spare fuses and fan belt, and complete tool kit ... you should compare the tool kit provisions shown in your owner's manual with what is actually in YOUR trunk!

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Warren Hall
1973 911S Targa

Wow,

This reminds me of my '73 (2.7 CIS). We just rebuilt the engine, and every once in a while... dead. Same as you, I was going to school, and dead. I Pull over restart, it runs. A week later same thing, dead. I pull over, it runs again. After about a month of inconsistent driving, I diagnosed it down to the CD box. The 'ole bosch CD box intermittently quit. I
replaced it with a Permatune (this was 1987). I drove to the guys garage, where he had set up shop, and lucky me (I was 16 at the time) I gave him $149.99 I think. It ran GREAT after that.

Good luck though!

Nick

Warren,
Just to confirm what you said...when my ignition is in the "on" position, the fuel pump should be operating? Last week when a friend of mine helped me fix my hard starting problems (somebody had cut the cold start plug connector; all that was left was the yellow and the red/black wires), we plugged the other connector to the receptacle on the back of the air-flow sensor. We tried starting the car before plugging it in. It started, and the pump was operating in the "on" position. After we plugged it into the one behind the air-flow sensor, we could no longer hear the pump operating at the "on" position, but the car still runs fine after a minute of idle hunting.
The Porsche mechanic who sold the car to me told me that I was to tie that plug up (one that goes to air-flow sensor) and never use it. I'm looking for a second opinion. Should I have it plugged in? What is it for? Thanks.

Jeff
1976 911S

Jeff, I can't think of a good reason for what that mechanic told you, unless the car has a CIS system problem that he could not fix, and he was doing a bit of CYA PR work for damage control? And, I think he owes you an explanation for why he told you not to plug in that cable (ever?) and just what was the pre-existing condition that prompted the caution from him!!! If you don't get the explanation, take him to small claims court for the cost of getting the CIS problems rectified at a dealer!!! The net effect of leaving that connector OFF is to have the pump run all of the time as the DEFAULT condition, something the factory CLEARLY did not want to do, or the switch would not be in the circuit at all. It has been too many years since I did any CIS troubleshooting, so I can't tell you what the circumstances are for the cut-off of the pump. If the car runs fine with the connector on the sensor, leave it there, but if the car quits on you, then disconnect it until you find out what was going on with your 'questionable' mechanic!

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Warren Hall
1973 911S Targa