Help 911 sc motor suddenly stopped wont start

[scrimpsher]

I don't even know where to begin, I am a new Porsche owner. Have a nice little 83 911sc picked up 2 months ago. Had the guys here in HB at the Emilig freshen up the CIS new injectors, whole tune up oil change. I put a cat delete and M&K muffler on it and richened it up. Short shift new fan, pully, belt, oil, have a bunch of parts I'm ready to do the interior, shift cullet get it dialed in. It was running tits even took it up ACH and ran with the Ducatis in the twisties like I was on my bike heel toe foot on the floor. No problems, little smoke, burns a little oil. Had a little.surging at idle issue .

then she let me down today. Was on my way home from work driving way too fast, high on the RPMS I know I shouldn't drive her like this but I ride motorcycles and I just expect my car to drive the same way. Plus some Benzo thought, well you know.. Was at 6k, just pulling into 3rd and the rps just went to zero, and didn't really know what was going on tried to restart while rolling, in N, then back in gear. Would not bump, still doing 80 or so, kept trying g til I rolled to a stop.

A lady pulled over and asked if I needed a fire exti guisher, I ran back and the rubber of my bumper was on fire from the pipe. It went out easy. The oil temp never got off middle, but the exhaust temps must have been super high, may have gotten a bit lean.

nevertheless I let it cool it'll turn turn turn turn turn but motor wont turn over some guy pulled over, he tried to help he pulled the middle wire out of the distributor cap and asked me to crank it over then he told me I had no spark then he left I'm not even sure you can check for spark that way I thought you had to pull a wire off the plug put a plug in the wire and ground it on the block but I don't know that much about these cars I jiggled the relays looked all around pushed all wires in all I could still wouldn't start called my wife she brought the truck and a tow strap and pulled me home. now I need new brakes keeping that strap taughtI'm home now and the car is with me and I don't know where to start I just spent so much money on this thing and I am so bummedI am NOT going to sleep until I can at least hear that motor I would appreciate any help adviceI'll be happy to pay somebody to come over and make her sing again I'm in Huntington Beach I don't mind getting my hands dirty I just don't know much about ignition systems and DC is fuel systems I am very new to this its not a classic Honda motorcycle or a Ducati. I'm in Huntington Beach 92649 sorry for the misspellings I'll clean it up later doing this from my phone trying to figure this car out. funny thing is my wife just got back this afternoon from Pelican parts spent a grip load of cash there today well at least last night and will call today anyway any help is very appreciated

[sc_rufctr]

Does the fuel pump run when it's cranking?

The relay that drives the fuel pump may be faulty. Maybe it's loose in it's socket or you have an issue with you ignition switch.
The CDI unit is very reliable so I'd check the pump before anything else. If that's OK check for spark etc.

Either way it's easy to fix. Good luck. (The "fire" has me concerned though)

[tirwin]

Ok, wow... Bad day.

Finding the source of the fire is obviously a concern. I have heard of rich conditions that plug cats and cause a fire, but you have a cat delete and new muffler.

Pulling the coil wire to dizzy is fine to test for spark. Need to look at the ignition and coil. Tell us what brand they are. Factory was Bosch but could've been replaced with PermaTune or other aftermarket. If you aren't sure, post pics. The factory Bosch CDI has a "whine" to it. No whine usually means failed CDI.

If you don't have a spare fuel pump relay (the red one in the front fuse panel), but one and put it in your glove box.

[scrimpsher]

Originally Posted by sc_rufctr

Does the fuel pump run when it's cranking?

The relay that drives the fuel pump may be faulty. Maybe it's loose in it's socket or you have an issue with you ignition switch.
The CDI unit is very reliable so I'd check the pump before anything else. If that's OK check for spark etc.

Either way it's easy to fix. Good luck. (The "fire" has me concerned though)

I hope so. The pipe is a bit close to the edge. But it hasn't done that before. I think it must have leaned out and got super hot. Maybe it is the fuel. I'll spray some starter fluid in there I have from my first month owning it having hot start issues, resolved now, or was. Almost everything in the fuel system was leaking. Now prob the pump with my luck.. Can I swap relays to see if its bad with one of the black ones?

[scrimpsher]

Originally Posted by tirwin

Ok, wow... Bad day.

Finding the source of the fire is obviously a concern. I have heard of rich conditions that plug cats and cause a fire, but you have a cat delete and new muffler.

Pulling the coil wire to dizzy is fine to test for spark. Need to look at the ignition and coil. Tell us what brand they are. Factory was Bosch but could've been replaced with PermaTune or other aftermarket. If you aren't sure, post pics. The factory Bosch CDI has a "whine" to it. No whine usually means failed CDI.

If you don't have a spare fuel pump relay (the red one in the front fuse panel), but one and put it in your glove box.

I will do that now. And will order extra relays. If it is the pump, coil, or cdi what can I use to get by for the weekend and what should I run for reliability and performance. Also what is this wine?

[scrimpsher]

SHE IS A RUNNER! THANK YOU! Drove around seems to be OK. It was a broken ground terminal on the coil. I made a new 16g stranded wire with soldered, crimped, and heat shrinked eye ends and grounded in the same location, on the intake manifold base. I will need to go through the wires, I noticed several crunchy / brittle ones. Is there a perfered gauge to use in the motor compartment. Also, should I go get a new coil? The posts looked pretty rusty.

[zedsn]

Looks like the muffler got hot enough to start to melt your rubber bumper end and looks like to much metal was removed with the muffler install.

[tirwin]

Glad you find the broken ground wire.

In a pinch you can swap one of the other relays for the fuel pump relay. Better then being stranded...

It's a good idea to keep a spare coil handy. Problem is the new Bosch coils are made in Brazil nowadays and they seem to have a high failure rate. Some people buy the MSD Blaster 2 High Vibration coil. If you get the MSD it's very important that you get that one because it's the only one they make that can be mounted upside down.

I am slightly concerned you might not be out of the woods yet. A common way the Bosch CDIs fail is that they shut down when they get hot. Get you a can of freeze spray and put it in the car. Go for a drive long enough to get the engine warm or maybe just let it idle in the driveway (but keep an eye on the temp gauge). If it cuts out again, use the freeze spray to cool the CDI box. If the car starts again, you have found the problem. If it doesn't cut out, then you probably found your problem with the broken ground wire.

Also, go get a fire extinguisher. I bought one of the Halotron types. They are a little more expensive but Halotron isn't an electrical conductor so if you have to spray it on your engine you won't short anything out. And you won't have to clean up the white mess off everything if you ever use it.

I also agree that your muffler tip looks short but maybe it's the angle of the picture.

[ossiblue]

Originally Posted by zedsn

Looks like the muffler got hot enough to start to melt your rubber bumper end and looks like to much metal was removed with the muffler install.

It looks to be more than that.

The rubber bumper is attached to the sheet metal of the rear apron. If you look closely, your muffler is touching that same sheet metal--it actually looks to be pressing against it. Simple heat transfer from a hot muffler to the apron is causing the rubber to melt. You need some adjustment of the muffler install, or some fireproof insulating material between the muffler and the apron sheet metal.

[timmy2]

Good find with the broken ground wire.
Crunchy wires is not a good thing. The engine harnesses see a lot of heat cycles and deteriorate with age. Usually the wiring to the alternator under the shroud sees the most abuse.

New harnesses are NLA (no longer available) from Porsche. I build complete replacement harnesses if you find yours is toast.
I just built a custom wrapped '83 engine and Lambda harness for someone here, post number 305 here:

Building SC and Mid Year Engine Harnesses

[sugarwood]

Originally Posted by scrimpsher

A lady ...asked if I needed a fire extiguisher,

In life, whenever asked this question, your answer will be a resounding "YES" 100% of the time.

[sugarwood]

tirwin, is this a good one to get? Where do you store it?
Kidde 466727 Halotron Fire Extinguisher, 2-1/2-Pound, 2BC - Residue - Amazon.com