Misfiring 3.2 Carrera
08-05-2002, 11:22 PM
#1
Misfiring 3.2 Carrera
Greetings,
Picked up a 1984 911 Carrera 3.2 (my first 911)for a reasonable price as a "project" car. Purchased it with some engine trouble, and wondering if anyone can help...
The engine is obviously running on 5 cylinders, and I doubt it has had all the scheduled valve adjustments done. I had it checked out at a competent (or so I thought) Porsche/BMW mechanic. Here is the relevant excerpt from their report:
"...air filter is dirty. #3 spark plug was very black. Compression readings are #1-160 #2-165 #3-160 #4-165 #5-170 #6-170. Engine does have miss. Does not seem to be ignition related. Valves are very noisy. Valve adjustment would be needed as next step to troubleshoot miss. Appears engine has not had any maintenance done for a while. 30,000 mile service needs to be done..."
On the phone I was told the #3 spark plug was replaced, but they acknowledged engine still has a miss. Injector wire to #3 is pulsing normally as well.
My question is two fold...1) Could a valve adjustment take care of the miss (car really feels off on power and chugs) and 2)What else would be the next thing to check (or what combo of things would you try?)
Thanks for your help!!!
Picked up a 1984 911 Carrera 3.2 (my first 911)for a reasonable price as a "project" car. Purchased it with some engine trouble, and wondering if anyone can help...
The engine is obviously running on 5 cylinders, and I doubt it has had all the scheduled valve adjustments done. I had it checked out at a competent (or so I thought) Porsche/BMW mechanic. Here is the relevant excerpt from their report:
"...air filter is dirty. #3 spark plug was very black. Compression readings are #1-160 #2-165 #3-160 #4-165 #5-170 #6-170. Engine does have miss. Does not seem to be ignition related. Valves are very noisy. Valve adjustment would be needed as next step to troubleshoot miss. Appears engine has not had any maintenance done for a while. 30,000 mile service needs to be done..."
On the phone I was told the #3 spark plug was replaced, but they acknowledged engine still has a miss. Injector wire to #3 is pulsing normally as well.
My question is two fold...1) Could a valve adjustment take care of the miss (car really feels off on power and chugs) and 2)What else would be the next thing to check (or what combo of things would you try?)
Thanks for your help!!!
08-06-2002, 12:16 AM
#2
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Does it miss all the time, at different times and in different ways, or only in certain situations: at start up, when hot, at idle, under hard acceleration, etc.
My 85 3.2 had a few issues that needed fixing but made diagnosis difficult: vacum leak, temp head sensor, DME relay, etc.
My 85 3.2 had a few issues that needed fixing but made diagnosis difficult: vacum leak, temp head sensor, DME relay, etc.
08-06-2002, 02:00 PM
#4
Rennlist Member
BGCarrera32:
You could have an intake leak. When I bought my 84 in 1999, it had a slight miss. The car had an aftermarket chip so we replaced it with the factory chip. Still had the slight miss. It turned out that the one of the intake gaskets was shot and the other 5 were just about done. Replaced the gaskets and problem solved.
You could have an intake leak. When I bought my 84 in 1999, it had a slight miss. The car had an aftermarket chip so we replaced it with the factory chip. Still had the slight miss. It turned out that the one of the intake gaskets was shot and the other 5 were just about done. Replaced the gaskets and problem solved.
08-06-2002, 11:31 PM
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BG,
Is gas getting to the #3. Smell the plug. Pull the injector and see if it's squirting.
Be certain about the spark diagnosis by connecting a plug to the #3 wire and check that it's sparking.
It's not likely a generic or a DME problem as the injectors all squirt together on each side.
Ned Monaghan
Is gas getting to the #3. Smell the plug. Pull the injector and see if it's squirting.
Be certain about the spark diagnosis by connecting a plug to the #3 wire and check that it's sparking.
It's not likely a generic or a DME problem as the injectors all squirt together on each side.
Ned Monaghan
