1987 911 3.2 misfiring when engine is cold

[manbridge 74]

Yeah the Beru inductive ignition wires are not made well.

The CDI cars had solid copper wires so they last about forever as there is not any carbon lost per each spark like in DME cars.

[stlrj]

Originally Posted by manbridge 74

Yeah the Beru inductive ignition wires are not made well.

The CDI cars had solid copper wires so they last about forever as there is not any carbon lost per each spark like in DME cars.

Don't fool yourself. The Beru cables on DME Carreras are also stranded copper and the CDI cars had airbox explosions due to ignition problems too.

[Johan91132]

Originally Posted by manbridge 74

In addition to the plug wires I’d checked the injectors again. New ones I see, but where did you source them? Had a customer car recently, injectors were already replaced but it didn’t last long. I put in Porsche injectors, car hasn’t come back.

Old injectors, ultrasonic and manually cleaned with 9v battery and car spray method by, new seals also. New porsche injectors would be nice, but can´t afford 2500usd injectors at the moment.

[Johan91132]

Can´t remember the firing order, but looking from the rear of the car the fouled plug is from the farthest cylinder and the lean? one from the middle cylinder. What is going on i´m baffled. Plugs are only 120 miles driven. This has been the order of the fouled and lean ones since last summer, before i started experimenting with new ignition parts and injector cleanings. 178 psi on all cylinders though.

Here are the links, embedding does not work it seems.

https://imgur.com/Mapm0Fn
https://imgur.com/AqG26og

[proporsche]

johan,,you did not replaced the cylinder head temperature sensor,right..? why don`t you do it as it was suggested to you on several posts?

ivan

[ischmitz]

Originally Posted by Johan91132

Old injectors, ultrasonic and manually cleaned with 9v battery and car spray method by, new seals also. New porsche injectors would be nice, but can´t afford 2500usd injectors at the moment.

Maybe one of them is leaking? How about you move them around to see if the problem follows the injector

[Johan91132]

Originally Posted by proporsche

johan,,you did not replaced the cylinder head temperature sensor,right..? why don`t you do it as it was suggested to you on several posts?

ivan

Been extremely busy, only had time to remove two spark plugs. Haven't driven the car for two weeks now. Will order the part when i find it somewhere where it is sensible to order it to Finland (taxes etc.).

[Johan91132]

Originally Posted by ischmitz

Maybe one of them is leaking? How about you move them around to see if the problem follows the injector

After cleaning them i installed them back in random order and if i recall correctly, the misfiring cylinders haven't changed.

Thought about the new brazilian bosch ignition coil i installed last year, could that be the reason? Or the new dme relay could be faulty or or. Tired of this troubleshooting.

[proporsche]

well you did not say about the coil..those are trouble......
the sensor if you are in Europa ..get it here..takes 3 days and you have it..
www.rosepassion.com
part number
P31527

Ivan

[Tea Tray]

Have you looked carefully at the hard to see vacuum tube mess / Venturi / hose party?
Years ago I started my 87 3.2 and it backfired once then ran very rough.
A tired vacuum line popped off and though the car ran it ran terrible.
I dug into the venturi assembly and its dozen connections and found pieces of paint from the inside of the brake booster.
I replaced the booster, booster vacuum hoses, other hoses and eliminated the venturi.

Don’t overlook or trust 30 year old rubber lines.
While you are there PLEASE check your 30 year old fuel lines.

[plasgar]

In your posts you state you do not have an O2 sensor installed. I am still learning a lot, but have similar problems to yours on my 88 911. I am chasing connection problems with my 02 sensor. Everything I am reading says that the O2 sensor can be removed on the 3.0 engined cars but the later 3.2s have to have it to run well and the symptoms of a failing O2 sensor are similar to ours. Again I am still chasing mine as well so can not provide a successful solution yet.

[cabmandone]

Originally Posted by plasgar

In your posts you state you do not have an O2 sensor installed. I am still learning a lot, but have similar problems to yours on my 88 911. I am chasing connection problems with my 02 sensor. Everything I am reading says that the O2 sensor can be removed on the 3.0 engined cars but the later 3.2s have to have it to run well and the symptoms of a failing O2 sensor are similar to ours. Again I am still chasing mine as well so can not provide a successful solution yet.

I could never tell a difference in my car with or without the o2 sensor plugged in and that was with the original chip.

[Cairo94507]

So I experienced a coil failure in my '87 3.2 motor. Started to mis-fire or break-up as I was driving and then it would clear up and run good. This all happened on a long trip in the car- 800 miles. Began at about the 200 mile mark and would cycle on and off. I thought it could be a tank of bad gas when I filled up at the 200 mile mark. Ultimately, 400 miles later it went completely dead. I carry a lot of parts in my "go bag" but not a coil. Flatbed and once home a new 3.2 specific coil solved the problem. I then discovered the failed coil was not 3.2 specific. It now has the correct coil. I never knew a coil had to be engine specific.

[Johan91132]

Originally Posted by proporsche

well you did not say about the coil..those are trouble......
the sensor if you are in Europa ..get it here..takes 3 days and you have it..
www.rosepassion.com
part number
P31527

Ivan

Ordered from design 911 and got a German made (Uro i think) CHT sensor for 100 euros. ordered also a distributor cap and rocker cover gaskets as they are leaking a bit.

Took two weeks for the parts to arrive and two weeks for me to change them (changing the rocker cover gaskets in the winter) + new WR4CC plugs. After changing the parts the car ran against hell. Plugs from cylinder 6 and 4 quite fouled after 20 minutes of test driving.

Took off the injectors and sent them to a professional injector shop. After a week got them back and installed them in an hour. After that the car has ran perfectly, and starts at the instant that i turn the ignition. Idle is still a bit low sometimes, other than that the car runs perfectly and has regained all the lost power.

Hopefully this is a permanent fix, quite fed up of the constant troubleshooting.

Here is a report of the injector test and service.