boonebeausoleil

Hey all, I recently bought my first Porsche and it is a 1983 911SC. I've been driving it around town for about two weeks now and ran into my first problem. It was running fine this morning and I parked it in my garage. About 2 hours later I went to back out and it wouldn't run. Initially it started and the engine ran for about a minute, enough for me to turn the radio on and back out of the garage into the driveway. I tried restarting it thinking maybe i had stalled it and it would turn and start up for about a second and then turn off. I've gone back and tried a few times more over the last couple of hours with the same result. I'm not a super mechanic or anything so I'm looking for some advice on how to try and trouble shoot this. Please and thank you!

Tmistry

so, the car turns over and the engine fires, runs fine for a minute, the stalls out?

if so, I’d say it’s a fuel feed related issue. Check the Fuel pump relay / fuse/ fuel filter. Might be coil related.

any other symptoms? Anything else to go on?

QUOTE=boonebeausoleil;18899395]Hey all, I recently bought my first Porsche and it is a 1983 911SC. I've been driving it around town for about two weeks now and ran into my first problem. It was running fine this morning and I parked it in my garage. About 2 hours later I went to back out and it wouldn't run. Initially it started and the engine ran for about a minute, enough for me to turn the radio on and back out of the garage into the driveway. I tried restarting it thinking maybe i had stalled it and it would turn and start up for about a second and then turn off. I've gone back and tried a few times more over the last couple of hours with the same result. I'm not a super mechanic or anything so I'm looking for some advice on how to try and trouble shoot this. Please and thank you![/QUOTE]

boonebeausoleil

I checked the fuses and they all looked good. All I can hear as that the engine fires for a second and then dies off. I don't have much else to go on right now.

Dr. 914

nothing to do with fuses, but rather spark and fuel, so if you have spark, then it is a fuel problem, often the control units (CD BOX) fail and then the other problem is that the fuel pump does not run. Check those first. I would be very hesitant to spray starter fluid (better brake clean) in the air box as it may blow, but that would tell you instantly if you have spark or not

turbo23dog

I had a no start issue and the problem was related to the fuse panel. The wire that provides power to the fuel pump and that was loose and making intermittent contact. Simply tightening the screw holding that wire fixed the problem.

Mark Salvetti

I don't know guys, the fact that it will run for a second and then shut down suggests there is spark and fuel, just not for long.

With the ignition on, remove the air filter, reach inside and gently lift the air plate. This should turn on the fuel pump. You should hear it running. You can also pull an injector, place it in a jar, and make sure fuel is flowing when you lift up on the plate. Don't do this for long, the "C" in CIS stands for continuous. It feeds fuel to each cylinder continuously.

The CDI box is bolted to the left side of the engine compartment. Silver aluminum box, maybe 4"x6". Can't miss it. When you turn the key to on (before start) does it whine?

I think a lot of these intermittent SC issues are usually traced to a bad CDI, a bad coil, or maybe the infamous green wire from the distributor.

Can you send some photos of the engine bay and the CDI box? I'm wondering if you have a Permatune box that replaced the factory CDI somewhere along the line. Also a major source of ignition failures.

Mark

theiceman

ah yes . the old permadoom...

and lets not forget the brazilian silver paperweight .. oh wait , i think i spelled coil wrong.

personally i will go with fuel pump or relay though

may need some CIS gauges for this one.

rstarga

I suggest pulling the fuel sock out of the tank and checking for debris. Classic symptom, runs for a bit then stops wait 20 minutes and it will start again but not run for long.
Sometimes it is the simple things

boonebeausoleil

After reading this and a few more things, I stumbled across this article on the CIS: https://ncr-pca.org/48

From the sounds of it I may be experiencing a hard cold start. I found a good youtube video on rebuilding the warm up regulator but I was curious if anybody in the community has experience in this. Is there a good way to test whether or not it is the WUR that is the problem? I tried generally searching the forum for warm up regulator but found the results to be very broad and overwhelming, so sorry for what may seem a lazy request for something previously written (I'll gladly take a recommendation to existing threads if they exist).

raspritz

Most of you guys are looking for zebras rather than horses. To the OP: It starts for a few moments and then dies. You are getting fuel up into the system by pumping the accelerator pedal a few times, so it starts. But then it dies. That suggests a fuel feed problem. Far up above in this thread Dr. 914 asked if your fuel pump is running. Is it? If not, that is your problem. If the fuel pump is running, given that you were able to successfully drive around town previously, I'd not worry much about a fuel system blockage. So, I'd move the ignition system and check every single electrical connection in the ignition circuit, looking for a dirty or loose connection.

Mark Salvetti

Yes. See my post #6 on how to confirm the fuel pump is running with the ignition on. You need to lift the sensor plate, because there is a switch on the back side that prevents the fuel pump from running if that plate is down.

You may well have CIS/warm up regulator issues, but I think they are more likely to affect driveability and issues with difficult warm or cold starts, rather than complete no-start.

If you want to dive into the CIS, you really need a set of gauges designed to measure fuel pressures in the system under different conditions. Besides fuel pressure, there are also some electrical checks for the warm up regulator (WUR). But before worrying about CIS, you need to confirm the fuel pump is running.

There is a guy on Pelican that is a CIS guru, he will rebuild a WUR for you, and he'll even loan you a good one to try out to see if that is really your problem. But you need to start with the gauges first.

See this long thread: http://forums.pelicanparts.com/porsc...ml#post7525606
And this video:
Mark

boonebeausoleil

I replaced the fuel filter just because the old one looked old and it was all new to me. When I turned the ignition on and tried tricking the fuel pump to come one I had nothing. The fuel pump wasn't turning on. I checked out the fuses and they all looked good but when I checked the terminals to the fuel pump I had nothing. I read in another forum to jump the relay switch for the fuel pump and then turn the ignition to on to listen for it to see if it was a bad relay or the pump. As soon as I did I could hear the fuel pump turning on again. I replaced the relay and she roars back to life. Thanks everybody.

theiceman

yup fuel pump relay .. you may have to spread the pins a bit to get good contact too.. if you look at the relay closely you will understand.. nice fix

Mark Salvetti

Those Chinese-made red fuel pump relays are junk. Consider having an extra spare in the glove box. I just bought a used German relay to have as a spare.

Mark