1987 engine quits
#17
Rennlist Member
This is the letter I sent to 911 and Porsche world after problems with my 3.2 Carrera
Subject: 3.2 Carrera Misfire cured thanks to Louis Trimmers letter
Dear editor
After months of mysterious occasional mis-firing on my 88 Carrera coupe, a
letter in your mag has paid for the subscription many times over.
Several months ago the car started to fire on 3 or 4 or 5 cylinders when
started from cold - then it would pick up on the offending cylinders when
the engine was warm. This would happen on about a quarter of the times the
car was started. I would also get the cold start surges mentioned in the
October 2000 letter from David Campbell.
I tried to have the fault diagnosed at Ray Northways (Porsche Specialist)
at Reading but we could never get the fault to occur when the car was
there - even when left for several days. Frustrating!
We considered (but resisted) new fuel pump/injectors/ECU (£800) and plug
leads and eventually just fitted a new distributor cap and rotor arm.
Still the problem persisted.
Then the "Resistance is Useless" article appeared in the March issue.
I took out all the fuses and cleaned both them and the terminals. ( front
fuse box and the little one in the engine compartment for good measure).
Not only has the car been perfect since but it feels smoother and more
responsive all round.
One pointer I perhaps should have followed up a few weeks ago was that the
stop lights suddenly didn't work and when I checked the fuse the metal was
completely crumbled with corrosion at one end of the fuse.
It would seem that the best tune up you can do on an old 911 is to replace
all the fuses.
The Bentley publishers manual for the 3.2 emphasises that voltages are critical in the ECU to sensor components system. Voltage reductions caused by poor connections can cause strange problems and performance issues.
Subject: 3.2 Carrera Misfire cured thanks to Louis Trimmers letter
Dear editor
After months of mysterious occasional mis-firing on my 88 Carrera coupe, a
letter in your mag has paid for the subscription many times over.
Several months ago the car started to fire on 3 or 4 or 5 cylinders when
started from cold - then it would pick up on the offending cylinders when
the engine was warm. This would happen on about a quarter of the times the
car was started. I would also get the cold start surges mentioned in the
October 2000 letter from David Campbell.
I tried to have the fault diagnosed at Ray Northways (Porsche Specialist)
at Reading but we could never get the fault to occur when the car was
there - even when left for several days. Frustrating!
We considered (but resisted) new fuel pump/injectors/ECU (£800) and plug
leads and eventually just fitted a new distributor cap and rotor arm.
Still the problem persisted.
Then the "Resistance is Useless" article appeared in the March issue.
I took out all the fuses and cleaned both them and the terminals. ( front
fuse box and the little one in the engine compartment for good measure).
Not only has the car been perfect since but it feels smoother and more
responsive all round.
One pointer I perhaps should have followed up a few weeks ago was that the
stop lights suddenly didn't work and when I checked the fuse the metal was
completely crumbled with corrosion at one end of the fuse.
It would seem that the best tune up you can do on an old 911 is to replace
all the fuses.
The Bentley publishers manual for the 3.2 emphasises that voltages are critical in the ECU to sensor components system. Voltage reductions caused by poor connections can cause strange problems and performance issues.
#18
Rennlist Member
also
There is a manual for the 911 3.2 Carrera printed by Bentley Publishers which contains this paragraph
regarding the electronic ignition on the 911.
Page 200-13 Engine management
"All the cars covered by this manual use engine management systems that rely
on precise electrical signals for proper operation. Some of the DME circuits
operate on very low current and are sensitive to increased resistance due to
faulty or corroded wiring or connectors. If any of these signals are
distorted, incorrect or missing the car can develop major driveability
problems."
There is a manual for the 911 3.2 Carrera printed by Bentley Publishers which contains this paragraph
regarding the electronic ignition on the 911.
Page 200-13 Engine management
"All the cars covered by this manual use engine management systems that rely
on precise electrical signals for proper operation. Some of the DME circuits
operate on very low current and are sensitive to increased resistance due to
faulty or corroded wiring or connectors. If any of these signals are
distorted, incorrect or missing the car can develop major driveability
problems."
#19
Instructor
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Join Date: Jun 2004
Location: Virginia Beach, VA
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1987 Coupe
Derick at Eurosport is the mechanic looking at the car. Derick has maintained the car for 8 years prior to me buying it so I trust him and his work. I will let you know the damage, hopefully later this week.
Thanks to all that have read and responded to this thread.
Thanks to all that have read and responded to this thread.
#20
George
As I reply to your post, I have similar problem with mine 87 and touched-up most solder joins in DME fix the problem,
Or you can send to Loren and cost $350.00
As I reply to your post, I have similar problem with mine 87 and touched-up most solder joins in DME fix the problem,
Or you can send to Loren and cost $350.00
#21
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George,
Did you see my post and link for LorenF? Looking after the mechanical care of a Porsche and repairing electronics are 2 separate issues.
Just my 2 cents. We have all learned by our experiences with local Porsche and their areas of expertise, or lack thereof. My 2 cents.
regards,
Steve
Did you see my post and link for LorenF? Looking after the mechanical care of a Porsche and repairing electronics are 2 separate issues.
Just my 2 cents. We have all learned by our experiences with local Porsche and their areas of expertise, or lack thereof. My 2 cents.
regards,
Steve
#22
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1987 now starts
Ok, I finally have my car back and it runs perfect, just like it did before the problems began. The cost to rebuild the computer was $500 plus shipping to and from the re-builder plus minimal labor to remove and re-install the computer. The company guarantees the computer for a year. Eurosport did a quick and accurate diagnosis and I couldn't be happier with their service.
Thanks to all that read the tread and responded.
Thanks to all that read the tread and responded.