pulsating feeling
 

I've had my 86 coupe for only 2 months and bought it without records. I know I know...
Anyways, at constant speed and rpm's i definately feel some type of pulsing. Not hesitation or missing but something you can just barley feel in your seat. The engine looks as though its been well maintained other than that but overall power seems a little down.
Any ideas? Thanks in advance.

Maybe it will stop when you run out of quarters http://www.pelicanparts.com/ultimate/wink.gif Sorry.
It could be almost anything, but when was the last time you replaced the fuel filter?

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Doug
'81 SC Coupe (aka: "Blue Bomber")
Canada West Region PCA
members.home.net/zielke/911SC.htm

Have you had it tuned yet? Might be a good place to start.

Joe Garcia
86 Carrera

If you feel a pulsating at constant speed I would guess it is tire related. Check for uneven wear.

You mention the car seems underpowered but not missing. If you think the pulsating is engine related I would check the plug wires and plugs.

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Daryl 91C2 Targa

the famous carrera mini-surge is the oxygen sensor. unplug it and go for a drive.

I only know a couple of things about Porsches and now John Walker is beating me to them on this board. I'm okay with it though, John. I enjoy your comments.

I too had some 'mini-surging' which disappeared when I reached in and unplugged the O2 sensor. But as far as a rhythmic vibration in the seat bottom, that is often an out of balance, or out of round, rear wheel.

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'83 SC

It wasn't rythmic just there. Anyways, John hit the nail on the head. Thanks guys. But should I keep driving around with the oxygen sensor unplugged(will it cause any damage) or should I replace it. Do you think this could be the cause of what I believe to be a weak engine.

With the O2 sensor unplugged or not working, your mixture should be set using a gas analyzer. This should be done on an otherwise tuned engine (valves adjusted, ignition set perfectly, etc.).

If your mixture is set properly, then your O2 sensor is not needed at all.

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'83 SC

replacing my o2 sensor fixed this for me...

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Adam Nitti
ajnitti@mindspring.com
www.adamnitti.com
'85 911 Carrera Coupe
PCA member, Peachstate region

if it feels like the a "brake" pulsating feeling then take care of it asap. i felt a pulsating feeling like the brakes were being slightly applied. also thought it was a flat spot in the rear tires. rear caliper ended up freezing on me on the freeway. hoses disentgrated internally. almost caused an accident. ck it out asap.
bob
'68 911L