Lousailor

I had a similar problem after I tried to wash my motor once. Try checking the rotor and cap again. Sometime water will get down in the pulley cavity and when the engine warms up and then cools down, steam will condense in the cap causing sparking (I fried my rotor), also check that you have the plug wires in the correct order on the distributor cap (I did that too). I also pulled apart each electrical connector, sprayed with 'Dry Wire' and then filled with di-electric grease to seal em up. Good Luck.

StupEd05

Well the spark is looking really good, a fried rotor would almost stop all spark right? It is a possibility though... Thanx! I'll replace the rotor as well (needs to be done anyways...)

82-928/89-S2

Yea, if you’re not able to start-up cold, this would not be the problem.

My temperature sensor in the S2 was going to infinite resistance intermittently. It would either start-up and die within a couple of seconds (from flooding), or it would start-up and run fine for as long as the engine was hot. If it died upon cold start-up, it would not start period until I waited several hours.

Food for thought…..

Something that happens quite often with my 924 is cross firing. I have an MSD-6A/Blaster coil in that car and if it sits outside for a few days in rain undriven, the wires, cap and coil get condensation on them and it starts miss firing out the intake or exhaust. When it fires out the intake, 9 times out of 10 it blows one of the rubber intake ducts off and you won’t notice it unless you physically shake the intake around. The larger the diameter of the hose, the more susceptible it is to being forced off during a miss fire through the intake.

Rock

Yeah right before it died, the car did backfire. Call me crazy man, but my money is on those vacuum lines. Im not sure if the air/oil seperator would let oil into the cylinders. All I know is once i replaced that, my problem was solved.

When the tube was broken, the car would almost NEVER start. I would have to crank it a while before it would fire up. When it did start, the car just sounded like an *** machine and would die when the gas was applied. The RPMS never went above 900 when it did start.

StupEd05

Just got back from Scott's and my DME and AFM checked out fine on his '84.

Rock - Im pulling the manifold tomorow morning, and im hoping to find the nastiest piece of crap vacuum hose in the world.

StupEd05

Well took the manifold off. No obvious tears, ruptures, or breaks in any vacuum hoses. I was surprised at how loose a few hose clamps were, then again a few were on there HELLA tight. Needless to say I came up with a few blood offerings for the Porsche gods, maybe that will help my cause... Anything else I should check for while under there?

Rock

Noo . Sorry man. I was almost for sure that we had the problem .

StupEd05

By rubber intake do you mean the intake boot that goes to the AFM?

When I took the manifold I laid it on the ground upside down, when I came back, there was about a tablespoon of oil that had drained out of it. It sure looked a lot like pure engine oil, but I suppose it COULD have been all that carb cleaner and starter fluid that was sprayed in there. Im gonna take all the vacuum lines into the parts store and put on fresh new vacuum lines along with a new gasket and put it all back together making sure ALL is tightened down properly and see what it does.

When I put my AFM on Scott's car, it started right up and would die instantly if not givin gas. We marked it off as the mixture setting on my AFM being way off.

Danno

"When I put my AFM on Scott's car, it started right up and would die instantly if not givin gas. We marked it off as the mixture setting on my AFM being way off."

Hook up a digital voltmeter to the AFM's output line close to the DME itself to verify that the signal is getting to the DME. WHen starting, the DME just dumps in fuel to get the car started, then checks for the AFM signal to inject proper fuel for idle. If it doesn't see an AFM signal, it cuts the fuel and shuts off the engine. Idle voltage coming from the AFM should be about 0.79-0.89v.

StupEd05

Good idea, I havent checked to see how much of that signal is acutally getting to the DME. Voltage readings ON/AT the AFM are perfect.

UPDATE: Just went to start taking all the vacuum lines off, and ran across one that is torn good. It connects to a housing that is attached to the rear air box support, and goes from a T next to the intake boot, down around the manifold and connects the the rear end of the manifold by the oil tube. All I did was twist it to unscrew the other end of it and it completely snapped off. I will get pictures of it ASAP.

Rock

I think you might have found the problem

Rock

Dude if that T is the idle control thing, and this is the little S line that connects to your intake manifold using a little metal insert, then this IS your problem

Look at the 2nd picture on the previous page and see if thats the one

StupEd05

No, that is not the same one. The one on mine has got some sort of braid on the outside and is about 1/4 inch in diameter. Right before the throttle body, on the intake boot there is line that goes off of the bottom of the boot. Right after the connection to the boot it comes to a T where it can go straight, or go right, the one that goes right is the one that is broken. It snakes down to the back of the air box support then around under the brake booster and up to the rear of the intake manifold. All those hoses are connected so no matter which one is busted it will kill all vacuum and pressure.

82-928/89-S2

Hi Aaron,

Sure, that’s a candidate. The point I was trying to suggest is that during an intake back-fire, anything between the intake valves and the AFM that is in marginal condition or is not connected well is susceptible to popping open on you and creating a vacuum leak. Let’s just hope you found the problem!

Rock

If it is directly connected to the intake boot that is a serious problem. Its no different than the Air/Oil seperator line that was trashed on mine. Either one of these tubes cracked, ripped or broken will cause unmetered air to enter the engine. Id try replacing that line man, directly connected to the intake boot isnt good....