PUMABRO

So recently I noticed the car(1988 944 N/A) would sometimes slip, or like freeze around 4k rpms but I didn't get too worried.... well a few days later and once the engine becomes warm and ideal temperature...my car won't go past 3k RPMs. It struggles to even get there. Almost a 100% I can't get on the highway because it wont accelerate fast enough.

Really puzzled and worried about this. If anyone can help I'd greatly appreciate it. thank you

mytrplseven

what year?

SeanR

Had an '88 in the shop that had this issue. Spent lots of time diagnosing it and the last thing we changed were the reference sensors. While visually they appeared in perfect condition, once those were replaced the problem went away for good.

PUMABRO

1988 944 N/A

Paul Waterloo

I would check that the catalytic converter is not shot and blocking the exhaust. Your symptoms match those.

PUMABRO

Only way to check that I assume is, taking the cat off?

Paul Waterloo

Either see if you have a rattling under the car when you start it/drive it/rev it in place.....do this cold and hot....if you do have this, you would then break the connection to it and then you could drive it and see if the power magically appears...if it does, it's the downstream piping (cat) blocking the air flow.

I do not have experience with 944's....but I've seen this on many cars before. Especially if you have the original cat on the car, it's not far fetched.

PUMABRO

See, this is what happened recently. I use to have a magnaflow with the stock cat. I switched over for a few reasons, but I went stock to go quiet into the new neighborhood. After I had gone stock, i noticed the whole car vibrates a lot past 5k RPMs, sing your logic, do you think maybe the clogged cat combined with a more restrictive stock muffler(trust me, it got a lot more retrctive and quieter) and that just over the pas few weeks its gotten worse and worse? Would be a relief if this is he problem.

konakat

If you have the same low revs in neutral as you do under speed then it is most likely the position sensors. In neutral there should be very little back pressure in the exhaust system, even if it is restricted. Clark's says that sometimes just removing the sensors and cleaning them will fix the problem, but I doubt that works very often in practice.

konakat

Easy enough to just create an exhaust leak and see what happens.

PUMABRO

the car revs normally in neutral, goes past 3k when warm without an issue.

PUMABRO

UPDATE.
I hate my life.

Also, after school car wouldn't rev last 4k in neutral. First felt super super sluggish so I waited for all students to leave then went. Struggled to get up to 40mph getting home

odonnell

I recommend deleting the cat one way or the other... it's old and a resonator in it's place sounds great on these cars.

Besides that, +1 to everyone who suggested reference sensors. They can cause all sorts of weird problems when they're on the way out (ask me how I know).

PUMABRO

Will go to the shop tomorrow to delete the cat. New Muffler/Resonator was ordered last week.. probably will come in next week. So will run straight pipe to a stock muffler, not looking forward to that. Thanks to everyone. If that doesn't work, I'll look into reference sensors.

PUMABRO