911 sc dies

JLW · 06-01-2005, 10:50 AM

Hi,
I'm new on this forum. I have a '78 911 SC, and I need some help. After reading the forum for a few days I decided you guys are the ones that can help.
My problem is my 911 will start fine and run for maybe 5 to 10 miles and just dies. It is as if you turned the key off. I pull over to the side of the road and my car will not restart. It will turn over and just as you release the key it will fire once or twice and stop. After about 15 minutes I try again and it restarts as if nothing was ever wrong.
I have replaced the fuel pump relay after emailing the tech help at Pelican, this did not held, and the fuel pump was replaced about 1000 miles ago.
The last email from Pelican was to drain the gas tank and check the screen in the tank. Bad thing is I just filled up with gas so I have not done so yet.
Does anyone else have an idea?
Please help.
Thanks

Oh Haha · 06-01-2005, 10:54 AM

Check for vacuum leaks at the intake area. When was the fuel filter replaced last? Did this just start? Check the easy stuff first.
Where are you located? A fellow Pelican may be able to assist on site.

bigchillcar · bigchillcar's Garage

fuel filter...classic symptom.
ryan

bigchillcar · bigchillcar's Garage

oh okay, i'll provide a little more explanation as to what happens: contaminants in your filter settle over time and the car starts and runs fine..until the contaminats begin to get stirred up, then the car gets starved for fuel, sputters and dies. wait a little while and 're-settling' works it magic and i starts up again..little while later, it dies again. when was this part last replaced?
ryan

JLW · 06-01-2005, 11:00 AM

No this did not just start, it started last summer, and I just parted it. This year I decided to start driving it again, so first I needed to get it fixed. I have not changed the fuel filter. That would be a good idea.
I don't think I have any vacuum leaks because it runs so well (when it does run).

911mot · 911mot's Garage

When it dies do you loose spark?
Coil anyone?

JLW · 06-01-2005, 11:11 AM

Ok, I just ordered a new fuel filter. I will try that. As far as the spark, I don't think so because it will hit a couple times, but not start as if no gas.

sammyg2 · 06-01-2005, 11:17 AM

If it isn't the fuel filter or screen in the tank it would almost certainly be an ignition problem, either green signal wire to the dizzy or the CD box. Let's hope the fuel filter solves the problem but I'm skeptical.
If the fuel filter clogs it the engine would start to run lean and gradually sputter and lose power, then die. If it just dies instantly as if the key was shut off, I'm thinking ignition.

JLW · 06-01-2005, 11:42 AM

Just went out to check the number on my fuel filter and decided to remove the distributor cap and check condition. The wire on back side from distributer had a broken connector. The wires still were making contact, but maybe not well. What is this wire for? Its called a signal wire in the catalog. I ordered one of these also.
Two more Questions what is the dizzy and CD box that Sammy referred to?

sammyg2 · 06-01-2005, 11:50 AM

Dizzy is internet shorthand for distributor. Just like tranny is short for transmission or transaxle. I type it that way because my fingers are lazy

The CD box is the capacitive discharge unit or electronic ignition brain.
If your signal wire is damaged that is probably the culprit. The signal wire takes a signal from the distributor that tells it when to fire, sends the signal to the CD box which, together with the coil, sends a spark through the rotor and cap to the correct spark plug.

JLW · 06-01-2005, 12:38 PM

Just wanted to thank everyone for the quick response. I will try the fuel filter and new signal wire. I hope this will help. If not I will be back for more advice. The more people you have thinking about a problem the better.
Thanks again

Oh Haha · 06-01-2005, 01:13 PM

Do one fix at a time. Start with Mr. coil wire. Even if you replace the fuel filter(which you should anyway), do it after the coil. Let us know what fixes the problem.

sammyg2 · 06-01-2005, 01:17 PM

Replacing the fuel filter and signal wire are both good things to do even if they haven't failed yet.
Unless you know how old the filter is it should be replaced, CIS doesn't like dirty gas. A dirty filter will screw up all kinds of things and end up costing you cubic dollars.
The signal wires have a reputation for failing after 25 years and leaving people stranded. They get old and brittle and if they break the car will not run at all.
Installing a new one will give you peace of mind even if the old one isn't giving you problems yet.
Good luck, the hardest problems to diagnose are the ones that happen intermitantly.

Carl83911 · 06-01-2005, 01:19 PM

sounds like a clogged fuel filter.

atomicboy · 06-01-2005, 01:30 PM

I had the same problem with my '68 S since last fall. Started fine, idled fine and ran fine for the first ten minutes. Replaced the fuel filter and it ran like a new car. My issues first started when I ran a fuel system cleaner through it. It probably loosened up some junk and the filter picked it up.

Ron
'68 911S
'77 911S (parts)
butt ugly Aztek

pa911 · 06-01-2005, 01:40 PM

Sounds like a Permatune!

Oh Haha · 06-01-2005, 03:47 PM

Oh, good call pa911.
If the other two options don't work, look here.

bigchillcar · bigchillcar's Garage

yeah, sammy..i think we're on the right track here: fuel filter or this broken signal wire (ignition). and i agree, don't replace them at the same time so you can determine cause for future reference. even if it turns out to be the wire, the fuel filter needs to be replaced if it's been more than a year or so, especially on these older cars with older fuel tanks. good luck.
ryan

stealthn · 06-01-2005, 06:08 PM

I think it's a goose chase (IMO) if it always starts after a 15 minute cool down I would be looking elsewhere...
AAR or Warmup regulator

Your opinions may vary

JLW · 06-17-2005, 05:35 PM

Hello I'm back with more questions. I have replaced the fuel filter and the signal wire, and have not had the dying problem yet but not many miles yet either.
My new question is what is the wire the signal wire is plugged into? The connector on this wire also needs to be replaced. I have looked on the host site and have not been able to find a replacement. My ignition is a permatune which was replaced before I got the car about 10,000 miles ago.