83 911sc cut out a couple times coming off freeway and no longer runs

[Freytag]

I just purchased a 1979 and a 1983 911sc from a great guy last week. The cars are both drivers and I don't think they have been driven much in the last couple years.

I had driven the 83 around town a little bit and decided to put in some fuel injection cleaner and then take it on an hour drive in order to let the cleaner work its magic. On my way home the car skipped a couple beats getting off the freeway and then stopped running on the off ramp. After 5-10 min the car started back up and I made a b-line for my office. The car stalled two more times but I was able to make it to my office. Now the car won't start.

I'm going to dig into it this weekend but I thought I'd reach out to see if you guys could point me in the right direction. Will the fuel injection cleaner mess up a fuel filter and/or release a bunch of crap that may be in the fuel tank.

Thanks for your input and I will post some pics on Friday.

[Freytag]

I had also put about a half tank of premium in the tank just before going on the drive

[Oh Haha]

Check the fuel pump relay, located in the front trunk fuse panel. It is typically red. They have been known to loosen up over time from vibrations. Just make sure it is seated fully.

[universeman]

To check fuel pump operation on the 83, remove the airbox cover and with the key in the on position, lift the mass airflow sensor with your hand (reach into the hole and locate the bottom of the MAF). If you lift it you will clearly hear the fuel pump buzz, if the fuel pump is working. If it's not, check the relay first, you can temporarily jumper it or just swap in the black relay for the horn, if the horn works (diagnostic purpose only - don't run it like that)

[scarceller]

When she does not start check for spark, you need to figure out if it's spark or fuel. Fuel issues usually sputter for a bit before the engine dies. Spark tends to die suddenly.

[vesnyder]

Check the fuel filter. They way it dies then restarts it may be getting clogged then unclogging over time as the car starts. Just my $.02. Good luck!

[jason2guy]

+1 fuel pump relay. happened to me

[TibetanT]

Pardon me for asking this dumb question, but when was the last time the car was serviced?
Are there any service records? I would check those to see if it's time for maintenance.

But, another thing which I picked-up from your post is: 1/2 tank of gas and HOW much fuel injection cleaner did you use? The whole bottle?

The reason I ask is, too much fuel injection cleaner in 1/2 a tank of gas can be problematic at times. Especially, in my experience, when lower octane gasoline is used. Find a Chevron station with 92 octane, or if California allows gas stations to sell non-ethanol gasoline, get some of that. Some times when these CIS car sit for a while, the ethanol will begin to suck in moisture which is not good for our cars. Might want to drain the gasoline tank and then fill her up with some good 92 gas.

Also check that the battery has enough volts to fire the injectors; 12V or higher.

I am no expert, but if I were you I would start with the basics, as some have suggested above check for spark, air and fuel delivery.

Good luck and "Welcome" to Porsche ownership!

[Freytag]

Hey,
Thanks for everyone's comments. I checked the relay and no luck. Just ordered a tune up kit and heater back date kit so that will be done next week along with the fuel filter.

As indicated in an earlier post, both cars haven't been driven much in the last couple years - so I knew I'd have a couple things to sort out and I'm totally ok with it

I used to have a '75s a couple years ago and I am so stoked to have another air cooled 911. I just want to go hug them

Have a great Friday and I will let you all know what I find out.

[gshiwota]

Check the distributor Green wire. If the wire is original it could be loose or frayed near the distributor. I chased down an intermittent cut out issue for a few weeks on my '83SC and I tried everything. Turned out the wire was loose. I replaced the wire and the car ran perfectly.

[Bob Kontak]

Originally Posted by TibetanT

But, another thing which I picked-up from your post is: 1/2 tank of gas and HOW much fuel injection cleaner did you use? The whole bottle?

Valid point.

The stuff can bust loose cooties. Varnish on the tank walls, etc.,

Even if not your issue, do the cleaner a time or two more. Run your gas down and pull the plug out of the tank bottom (outside your garage or pay for the service). Check out "debris" content and post. Not a today project, but good PM. 22mm female male hex needed. Replace circular seal. Perhaps strainer if looks like it is needed.

FWIW. I did this in the early 2000's with my 81. Gas drained was way cleaner than I expected. I did no flushing.

[emac]

My guess is the CDI gave up the ghost
Ask me how I know. Mine quit and started a few times and I replaced just about everything thinking it would be the last thing to go. I was wrong
Ernie

[Freytag]

Shown below is a quick little video from the wife

http://tmblr.co/Zl7FYv1zmOjTW

[tirwin]

Originally Posted by universeman

To check fuel pump operation on the 83, remove the airbox cover and with the key in the on position, lift the mass airflow sensor with your hand (reach into the hole and locate the bottom of the MAF). If you lift it you will clearly hear the fuel pump buzz, if the fuel pump is working. If it's not, check the relay first, you can temporarily jumper it or just swap in the black relay for the horn, if the horn works (diagnostic purpose only - don't run it like that)

Technically, it's not a MAF on an '83. Similar concept. And your basic premise is correct.

[tirwin]

Originally Posted by emac

My guess is the CDI gave up the ghost
Ask me how I know. Mine quit and started a few times and I replaced just about everything thinking it would be the last thing to go. I was wrong
Ernie

Could be. Working again after cooling off is a sign of failed or failing CDI. Get a can of freeze spray or one of those cans of compressed air and keep it in the car. If it starts cold and then quits when the engine is warmed up, trying using the freeze spray or turning the can of air upside down and spraying it on the CDI box. If it starts after cooling off you've found your culprit.

It's either fuel or spark. Try to rule one out and then focus on the other.

[Freytag]

Here are a couple photos of the wife reading the times as we shoot up the coast and the wife's 79 parked in our office garage. Good times

[Freytag]

Just took a photo of a part that's broken below the fuel pump. The wire is still attached and it looks like it plugs into the ox sensor.

[scarceller]

That's the O2 sensor signal harness, common failure for that connector to break. Do you run the O2 sensor? If not no big deal. If you attempt to repair this connector be very careful as that green wire has a center conductor as well as a braided shield DO NOT accidentally allow the shield to touch the center conductor, if they touch it will cause a false lean reading and your mixture will go very rich! Ask me how I know!!!!

[Bob Kontak]

Originally Posted by scarceller

common failure for that connector to break.

The broken surround does not mean the connection has failed.

[Freytag]

Thanks for letting me know about the connector for the 02 sensor. I will be running the sensor and the green wire looks broken - so i will be replacing since I live in Cali. Does this wire just run back to the CDI box?

I checked on the below listed items and also removed the heater fan assembly in preparation for the heat backdate kit thats coming my way.

1. Installed new fuel pump relay
2. Pulled off the air filter, turned on the key and pulled down the flapper sp? in the air housing. All I heard was a buzzing that I think is coming from the ignition?
3. Loosened the top nut on the fuel filter, turned on the key and looked to see if any gas would pump out - nothing
4. Turned it over a bit and pumped the pedal - didn't smell any fumes like I might be flooding it.

I also checked all my fuses and none are blown. Does the fuel pump have a fuse along with the relay? (I'll check the bentley)

On Sunday I'm going to pull the fuel pump relay from my 79 and see if that'll work

Fun day even though I didn't get the car to fire up