tall02

Fellow drivers

I have a 1992 964 Porsche C2. Sometimes when I am driving down the road the engine uts t and dies for 2 to 5 seconds. Sometimes at 35 other times at 65 mph. I believe it is happening when I am driving over a rough road or bridge. It sounds like a loose electrical connection. At night my dash lights do not go out when the engine dies. I do not believe it is weak fuel or fuel cutting off since the engine does not sputter but dies like someone turned the key off. I cleaned relay #11 and relay#33. I checked the plug on the computer under the seat. I have ordered a new ignition switch.

This engine cut-out has only started since I rebuilt the engine 1500 miles ago. It has only started acting up in the last 500 miles once or twice when I am out on a 10 miles to 40 mile ride. Otherwise the engine runs great.

Anyone ever experienced their engine cutoff like this?

Any advice would be welcomed.

Thanks

joey bagadonuts

Did you do any mods during the rebuild? Change any components? Those are the items I'd check first. Like you said, it may be a loose wire or something along those lines.

tall02

The rebuild was stock other than elimination of seconday muffler. But the top end was rebuilt with a new clutch and pressure plate.

Streetfighter

Do you have a K&N filter for your air intake? I have one and the engine when the fin is down obviously gets very hot and the car sucks in some of that hot air and the acceleration will lack a little bit. Where it kind of cuts out like your talking about.

joey bagadonuts

I was hoping you'd say that you replaced the chip. If the contacts are not firmly lodged, they can pop loose over rough roads. This happened to me and was easily fixed.

Hmmm ... anyone?

bpras@msn.com

Do a search on ignition coils and wires. They can also cause the type of problem you are having.

PCar SBA

Believe it or not: I had the very same issue and was 100% convinced that my spark cut out. No sputter but a complete "nothing" for seconds at a time. Hooking up my hammer it turned out to be the O2 sensor signal. The signal went from its ususal swing between 0.1V to 0.9v to 0.00V due to poor contact at the connector in the engine bay. And the engine literally felt like someone cut power to the coils or turned the key off. After cleaning the contacts at the 3-pin plug it never happened again.

tall02

Thanks PCar SBA

I will check the O2 sensor connection. The sensor was replaced one year ago before the engine rebuild with no issues last year. But pulling the engine in and out may have caused some dirt to enter the connection or it may just be loose.

Thanks...I will inspect

Best regards

notfastenough

Any follow up on this? How was the the problem eventually resolved? Thanks.

perlfather

Another possibility is the ignition switch - inexpensive and prone to frequent failure.

2002M3Drew

Check the plug on the other end of the ignition switch. On my SC there is literally a little row of plugs under the dash near your left knee, one of which is for the ignition (another for the wipers, etc). I believe it is the same with the 964s. They come loose at first and do what you are describing, and eventually you'll have dash lights but no ignition. Push the plug in and it works. Happened once with my SC, and once with a 3.2 Carrera belonging to a friend of mine at the track.