Please help!! Engine running problem
Thread Starter
Intermediate
Joined: Jul 2008
Posts: 30
Likes: 0
Please help!! Engine running problem
Hi,
I have a manual 89 C4 964, which I have owned since December last year. It's my first Porsche which I proudly purchased at the age of 28 after driving MK 2 golfs for years. My brother took the car out one morning and came back rather upset stating that it had stopped working. He had been approaching traffic lights when all of the warning lights came on when it died, and would not start again
Got it to the first garage (4 months ago) and they didn't have time to fix it until November, no good. Took it to second garage who have taken it out and replaced the valves and sorted a couple of oil leaks, reprofiled a nick out of the camshaft and put on an RS clutch and flywheel kit.
Now the car won't run properly. It's running on 2 cylinders and occasionally spurts into life (maybe on 6) revving highly before dropping back down to the 2 cylinders and stalling. He had since had the engine out and put back in, checking the valve timing, distributer, coils, fuel rail, manifold, changed the ecu and it's still no better.
The owner of the garage and his mechanic have now been stuck for about 2 weeks and I'm getting really concerned about potential of rising costs and time involved and I've been without my car since May! I don't think that he is incompetant, he has been very helpful throughout, but he may have struck on an anomoly and is now double checking things.
Please can you shed any light on this, any ideas, similar experiences? Or if you're a whizz on 964s, you're in the UK (possibly near Gloucestershire), would you mind sparing the time to speak to the garage. (if you're interested I will pm his details - don't want this to be looked upon as a name and shame because largely I am happy with the service so far).
Any help would be greatly appreciated.
Many thanks
Matt
I have a manual 89 C4 964, which I have owned since December last year. It's my first Porsche which I proudly purchased at the age of 28 after driving MK 2 golfs for years. My brother took the car out one morning and came back rather upset stating that it had stopped working. He had been approaching traffic lights when all of the warning lights came on when it died, and would not start again
Got it to the first garage (4 months ago) and they didn't have time to fix it until November, no good. Took it to second garage who have taken it out and replaced the valves and sorted a couple of oil leaks, reprofiled a nick out of the camshaft and put on an RS clutch and flywheel kit.
Now the car won't run properly. It's running on 2 cylinders and occasionally spurts into life (maybe on 6) revving highly before dropping back down to the 2 cylinders and stalling. He had since had the engine out and put back in, checking the valve timing, distributer, coils, fuel rail, manifold, changed the ecu and it's still no better.
The owner of the garage and his mechanic have now been stuck for about 2 weeks and I'm getting really concerned about potential of rising costs and time involved and I've been without my car since May! I don't think that he is incompetant, he has been very helpful throughout, but he may have struck on an anomoly and is now double checking things.
Please can you shed any light on this, any ideas, similar experiences? Or if you're a whizz on 964s, you're in the UK (possibly near Gloucestershire), would you mind sparing the time to speak to the garage. (if you're interested I will pm his details - don't want this to be looked upon as a name and shame because largely I am happy with the service so far).
Any help would be greatly appreciated.
Many thanks
Matt
Burning Brakes
Joined: Jun 2004
Posts: 762
Likes: 10
A few other things you didn't list, but am wondering if you checked (No insult intended with the basic questions).
Did you check or replace the ignition wires, replace the plugs, etc?
Are you sure all of the ignition wires are going to the right place?
How about something really basic like failing fuel pump or clogged fuel filter?
Did you check and/or clean/replace the air flow meter?
Did you do a compression or leak-down test?
How about any air or vaccuum leaks?
Do any codes get thrown that you can pick up with a hammer?
Is there any smoke or discharge out of the exhaust?
Did you check or replace the ignition wires, replace the plugs, etc?
Are you sure all of the ignition wires are going to the right place?
How about something really basic like failing fuel pump or clogged fuel filter?
Did you check and/or clean/replace the air flow meter?
Did you do a compression or leak-down test?
How about any air or vaccuum leaks?
Do any codes get thrown that you can pick up with a hammer?
Is there any smoke or discharge out of the exhaust?
Burning Brakes
Joined: Jun 2004
Posts: 762
Likes: 10
Addict
Rennlist Member
Rennlist Member
Joined: Jul 2003
Posts: 2,577
Likes: 52
From: Atlanta
It takes compression, clean fuel, and spark, all in the right sequence, to make a cylinder fire. The devil is always in the detail, but the basics are pretty simple. A competent Porsche mechanic should isolate the problem in less than half a day. You may want to reconsider your trust in these guys if they can't find the problem after two weeks. You also may want to quiz your brother in more detail about what exactly happened when he was driving. Here are some questions to ask the mechanics:
What diagnostic codes are listed?
What are the compression or leak-down numbers, by cylinder?
What does the ignition scope show (primary and secondary system, each cylinder)?
What is the fuel pressure?
Any sign of fuel contamination?
What is the electrical system voltage?
Any discrepancies in this basic information should direct the activity in the direction of the real problem.
Best of luck.
What diagnostic codes are listed?
What are the compression or leak-down numbers, by cylinder?
What does the ignition scope show (primary and secondary system, each cylinder)?
What is the fuel pressure?
Any sign of fuel contamination?
What is the electrical system voltage?
Any discrepancies in this basic information should direct the activity in the direction of the real problem.
Best of luck.
Thread Starter
Intermediate
Joined: Jul 2008
Posts: 30
Likes: 0
Hi guys,
many thanks for all of your responses. They have found a break in the wiring from the distributer back to the ECU after all of this and on soldering the wires the car is now acting normally. Thank god! I'll post a couple of pictures once I've got it back and cleaned it. The positive I can take from this is that everything has been checked and double checked, with other issues being resolved from the double checking. It may have cost a bit more but the bill is still reasonable at least.
Regards
Matt
many thanks for all of your responses. They have found a break in the wiring from the distributer back to the ECU after all of this and on soldering the wires the car is now acting normally. Thank god! I'll post a couple of pictures once I've got it back and cleaned it. The positive I can take from this is that everything has been checked and double checked, with other issues being resolved from the double checking. It may have cost a bit more but the bill is still reasonable at least.
Regards
Matt
