3.2 miss out randomly
 

Hi

I have a 1986 3.2
Last week started to miss out the ignition randomly, specially on load
Sound like the ignition on wrong place

Already changed the follow without succes
- Spark plug + wire + rotor + distributor + fuel filter + ignition coil
- Fuel pressure ok
- DME relay replaced
- Other DME tested

The speed and ref sensor measure 1000Ohm
The CHT sensor in cold 2400Ohm warm 300ohm

Bit confused now what to do

Not sure if this is helpful or not, but a while back I was having some issues (starting problems IIRC), Anyway, someone mentioned that the resistance on the sensors isn't necessarily consistent as I had assumed. In my case I found it would very considerably! I replaced them and problem solved. To be honest your problem is very different that what I was dealing with but wanted to mention the resistance issue. Maybe Ischmitz will chime in and offer better help.

Check all your grounds

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My sensors would test out fine, but when they got hot, they were flaky. I changed them out, and the car has been flawless ever since.

The other weird running issue I had was the old original coil was failing after working fine since 1985. There is no good replacement coil for a 3.2 Carrera, except to find an original old black used coil that works.

I have yet to see a new coil designed to work with a 3.2 DME G body 911, one with the proper voltages that are good quality.

Ground checked and cleaned, it is only 1 place above the cy,inder 1?

ordered the 2 speed sensors.

Thank you for the help!

Seppo,

at the beginning of the summer, I went through what sounds exactly like what you are currently experimenting. Especially with respect to load . . .

I did all the changes, relays, grounds, etc... that were suggested on the forum. It then turned out that my 37 year old fuel tank was rusted beyond repair, and the rust residue were clogging the fuel injectors.

Installed the new fuel tank, and voilà . . . no more " miss out ".

I had an issue with my 3.2 and it turned out to be the coil. Never ever had a coil go bad, but it did. Replaced the coil and it was back to perfect. Good luck with the hunt.

There is another on the front of the transmission that is exposed to a lot of road grime. There may be more, my 3.2 was out of the car when I got it and I haven't started putting it back yet.

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