joes

I’m working on a friend’s car that at first glance appears to be an early CIS car that someone has installed a 3.0 L -jet motor in(only because they didn’t have L-jet in an ’82) but after real close inspection looks like that it is one of the first cabriolet cars with L-jet. The VIN date is 2/82 and the motor serial # is something like *64e-00071, everything appears to be factory and it is badged “911SC”. I have given up worrying about this part as it really doesn’t matter.

The car was given to my friend by his g-father and was in a non-running condition (and was bought non-running)
It didn’t take long to determine that the DME was bad. Another one was secured and installed which after less than an hour’s running time cooked with visible smoke. The DME was sent to someone for repair and returned and installed. The car ran but very rough and smoked apparently enough for the fire dept to drive by for a look. The owner shut it off in fear that it was going to cook the replacement DME. In steps yours truly. I did all of the voltage/ continuity/ resistance checks through the DME plug and everything was spot on. I pulled the injectors wiring plugs and checked each injector for resistance, 2.5 ohms’ what was good. Checked for shorts in the injector harness everything good. Well let’s start it up. The car started immediately (had been setting 7 months) with a little smoke (that’s ok) but wouldn’t idle and I could hear it coughing a little like it was out of time. I loosened the distributer and turned it and it smoothed right out. Now I know that the DME controls the ignition timing on this engine and that it picks up it its initial TDC from the reference sensor so there may be a problem with its relationship with the pin in the flywheel or something, that I still need to check. One of my questions is can the cam timing be off or the chains stretched that by turning the distributer would compensate for. We still may have a DME problem that hasn’t surfaced yet ?? I haven’t driven the car yet we just shut it off for further study in fear of a cam chain problem. Any help or suggestions would be great. Oh yea the clock says 90,000 miles, the engine looks good and clean but the driver’s seat suggests different. Thanks, Joe.

Peter Zimmermann

As a starting point, why don't you just post the VIN and engine number? At least then we'll have a starting point...

g-50cab

Vin will tell whether it's a targa that's been converted - which would be the most likely. No 83 SC cabs till 1983 - No DME contolled engines until 1984.

The distributor has a bolt that keeps it from turning - did you loosen and turn that too or just the cap?

Most of the engines I have heard that have loose timing chains or collapsed tensioners make a hell of a racket. Not something you could casually mention.

joes

The engins sounds good'n tight no chain slapping noises. I loosened the bolt that holds the dist. down. There is an adjustment slot in it. I'll post the numbers later.

jakeflyer

"Don't be so quick to judge that that car isn't factory. The cabs were the first cars to recieve the 3.2 engines since they were new bodies on the line, they got the new engine." -----------You are wrong or Porsche is wrong. According to Porsche the 1983 cab had vin # wp0ea091xds170001-1781. '83 eng # was 64D etc and according to them it was a 3.0, 3.2 started in 84 # 64E etc, continuing F, G, H, J. PCA sells a handy book called the Porsche Family Tree, saves all kinds of everyone's time

joes

Yes I had to amend that. What I ment to say was I think that the cabs were the first to get the L-jet motors. I have some numbers. WPOEA091XCS161401 the engine S/N 64E00071 I think this was on a sticker on the engine CPR18D601 I'll get the engine number later. My real problem is the running condition of the motor.

Peter Zimmermann

Now we're getting somewhere. The car, for the record, started life as a 1982 911SC TARGA, and whatever it might be today it now is fitted with a 1984 3.2 liter Carrera engine. Engine swap cars can have a wide variety of running problems that original cars will never have, so now I'll re-read your initial post from a better perspective...

g-50cab

DME Relay? Have you swapped it? (not the actual DME but the relay that controls the fuel pump) What sort of shape is the reference sensors? How about the O2 Sensor, CHT sensor?

joes

Thanks Peter for the real story on the car. I checked the DME relay it is good, the head temperature sensor is good, I didn't get readings from the oxygen sensor, that is something that I still need to look at closer. My real worries are why did the first two DME,s fry? and will the repaired one that is in it suffer the same fate? The next question is when I move the distributor why did it smooth out the engine? That was not supposed to happen. I'm going to look at the position of the pin on the flywheel for the reference sensor to confirm it hasn't been messed with. remember now car does run. Thanks for the help, Joe

Oldtee

When you are talking about smoking, are you talking about smoke from the exhaust? If so, it may take some time to burn the oil out of the muffler and cat. Run it for a long while and buy the fire department a beer the next time.

joes

Thanks to Pete for running the number's on that car. (I went out and bought his book yesterday) Is it possible that in order to use the '82 trans on that car that they had to modify an '82 flywheel to work on the '84 3.2 engine? or will the 3.2 flywheel work OK? That would explain a lot.

g-50cab

Yep - you have to slot the bell housing for the DME reference sensors too - I have seen a few hack jobs in my time.

So, is it a 3.0 with a 3.2 fuel delivery system and motronic?

Moving the distributor like you describe would advance or retard timing, right?

joes

Are you saying that the 3.2 flywheel WON'T work on that car and they had to change to the 3.0 flywheel and drill and cut out a tooth. (Thats what I'm going to look at this afternoon.)

g-50cab

3.2 flywheel will work and that's usually the route you go putting a 3.2 on a prior car. You do have to modify the 915 bell housing to make room for the reference sensors - BUT - you really need to make sure the reference sensors are at the correct depth vs the reference sensor pin in the flywheel or you can all kinds of issues too.

joes

That's what I'm going to look at when I get off work. I'm used to working on the Motronic system but on 944's. I've had to redrill pins that had been sheared off by a sensor that had been set too deep. By the car running better by turning the distributer should indicate there's something up with that setup. thanks.