Greg-slant/cab

I have looked at some previous threads and I am not sure if this covers it directly or not. If it does I apologize. I was driving last night, everything running fine. A nice 4 mile cruise to the store. The car was at a good temp. about 190 degrees and the oil pressure was fine. I came to a stop sign and noticed the car was idiling(sp) a little rough. I took off from the light and noticed a definite miss while it was running. It did seem to go away at a higher rpm. It ran this way all the way home. This morning I went out to look have a look and being the ever optimist was hoping it was going to be ok. Well, I started it up and still has a definite miss in it. I let it warm up a little and took it for a spin around the block. The miss is definately there through the entire RPM range It also has a definate lack of power. I have checked the spark plug wires and looked for anything obvious. It has within the past few months, new wires, plugs, rotor, cap, points. 1975 2.7L. Any suggestion on where to start and/or testing procedures? Thanks again to everyones help on this board..

[ 08-06-2001: Message edited by: Greg-slant/cab ]

[ 06-16-2001: Message edited by: Greg-slant/cab ]

[ 06-16-2001: Message edited by: Greg-slant/cab ]

Mark Kiwior

Hi Greg,
Sounds like you have an ignition problem. If it were me I’d disconnect one plug wire at a time with the engine running, if unplugging one does not make any difference in the way the engine is running you have found your bad plug wire, plug or bad spot on the cap.
Mark

Dial 911

Greg, for what it's worth....
You mention you replaced all the wires, cap, etc. Good.
But when you were sticking the long plug connectors down into the head, are you sure you made firm contact?? It's easy to think you have them snapped on, when they are not quite there. This happened to me...the car ran fine after a plug change. I drove over a stretch of rough road, and noticed a slight miss. Stopped at the side of the road to check...the #6 lead was popped out, but still in marginal contact with the plug.

BTW...if you have to fool around with the HV ignition wires on a running motor, stand on dry ground, and wear a thick rubber glove. Unlike some other car ignitions, these can kick your **** clean across the yard (don't ask me how I know!)

Greg-slant/cab

I did try removing one plug wire at a time to see if I could isolate the problem. It really did not seem to make much of a difference. In other words I could not really isolate one cylinder. Ss far as the replacement stuff goes. I replaced all those items about a month ago. I did double check everything to make sure it was plugged in really well....Still looking for an answer.

BrianKeithSmith

I am experiencing the same problem in my '83 930. Car does not idle properly (about 600RPM) and doesn't seem to have any power.

It is as if it has no compression.

I'm curious to find out what the culprit is on your car. I'm taking mine to my mechanic on Monday. He says it can't be anything major....

Brian

Tim.

Hey Greg,
Had a similar problem a few years back. Mine started slowly and got progressively worse. I had 2 different shops look at it, as well as my personal mechanic (ex-shop mech). Motorwerks of Barrington was convinced it was internal and requested a number of times to drop the engine. I had a feeling (or just hope) that it was the ignition wires. I had Motorwerks put them in against their wishes and voila, the problem was fixed. When I first noticed the problem I checked that the wires were on tight with the plugs, but the damage to one of the wires was not noticeable until it was out of the car, and only then by knowing it was the damaged one. But if yours are new.....

Bill Gregory

Greg,

Over on the rennlist 911 email list, someone describes a problem with a Permatune CD box where when the engine warms up, it starts missing. The owner swapped a Bosch box in, and the problem went away. Two others have added that this is a common problem with Permatunes. The last post says to go to the Permatune website, and email for technical help, and the tech there will provide a technical debug sheet.

Ralf, Katherine & Sasha

hi greg,

sounds to me like a random misfire, nothing "mechanical-internal".

I guess we are all agree that this can be caused by about 10.000 problems such as vacuum leak, bad fuel quality, software issue ecm, , etc. etc. etc.

Did the engine miss right away when you started the car? Did you had a hard time to start?

I would recommend to see you mechanic, put a system tester on it and see if there is a stored code you can follow up on it.

Ralf

Ralf, Katherine & Sasha

hi greg,

just saw it's a 75 2.7 - not a lot to do with a system tester 2



Ralf

Dial 911

Greg says he has a 1975 2.7, so he sure won't be seeing any "codes". However, Greg, most decent shops would be equipped with an ignition system scope. This may pinpoint your problem to the mechanic.

Greg-slant/cab

Once again thanks for all the replies. I already have an appt. at my local shop. I always try to correct them on my own. At this point I am pretty confident that it is a fuel delivery problem and not an ignition problem. I am suspecting maybe a clogged injector or a partially clogged injector and or fuel filter. The timing of the incident while driving makes me suspect that. I will continue to troubleshoot and hopefully will be able to cancel that appt. that I have set.

cubiclex - 77 911s Targa

Greg, I recently had the same problem. I replaced plugs, wires, cap, and rotor and still experienced problems at lower rpms. I replaced the injectors last weekend and what a difference it made. Car runs great now.

Greg-slant/cab

I think you might be on to something. After alot of troubleshooting and reading I am convinced it is a problem on the fuel side. I will be replacing filters and having the injectors checked. I hope it is a fix.

Kurt V

Brian your problem sounds exactly like when my car has fouled a plug and is only running on five cylinders.

Greg-slant/cab

UPDATE......Well, the miss is finally gone. After checking all the electrical components and troubleshooting I came to the conclusion that it was on the fuel delivery side. I followed Bill's post on the injector tuneup and it worked great. I replaced the injectors and the fuel filter. It is running like a champ. Thanks again Bill for the easy to follow directions.