HELP-- 1988 911 Flatens out at 4500 rpm

Boise911 · 08-22-2008, 07:57 PM

I am the recent new owner of a 1988 911 CE with the 3.2 with 105,000 original miles. I've recently noticed some very subtle "missing" characteristics throughout the power band, but when I hit 4500 RPMs it is almost as if a governor kicks in and the there is a flattening of acceleration. I can push the car beyond the 4500 RPMs, but something is still amiss. Generally speaking the car is in beautiful shape and has been well maintained over the years and I feel like I found a prize (other than this issue for which I am posting.

I had it with a mechanic today who pretty much works on Porsche-- he said he could not tell me what the problem was of yet, but suspected electrical and wants me to bring it back next week. Any other ideas? Anyone have a similar experience?

Your help is appreciated!

Jagshund · 08-22-2008, 08:00 PM

Does it have an aftermarket ignition?

Boise911 · 08-22-2008, 08:23 PM

I don't believe the ignition is original, but I can verify with the mechanic as he's performed all the maintenance on the car over the last 12 years.

Boise911 · 08-22-2008, 08:24 PM

Correction: I do believe the ignition is original.

madmmac · madmmac's Garage

More info would be helpful..last tune up...last valve adjust...last air and fuel filter change.

Check to make sure you are actually getting full throttle. Have someone floor the car while the engine is off and check at the engine that the throttle is just contacting the stop. If not, shorten the linkage under the car by the transmission until it does.

With the wavering speeds, you may need to move the wiper in your maf. This describes the process for a 944, but it is pretty much the same for a 911.

http://www.clarks-garage.com/shop-manual/elect-22.htm

And Welcome aboard!!!....now post the obligatory picture of your car.

Steve@Rennsport · 08-22-2008, 08:49 PM

Quote:

Originally Posted by Boise911

I am the recent new owner of a 1988 911 CE with the 3.2 with 105,000 original miles. I've recently noticed some very subtle "missing" characteristics throughout the power band, but when I hit 4500 RPMs it is almost as if a governor kicks in and the there is a flattening of acceleration. I can push the car beyond the 4500 RPMs, but something is still amiss. Generally speaking the car is in beautiful shape and has been well maintained over the years and I feel like I found a prize (other than this issue for which I am posting.

I had it with a mechanic today who pretty much works on Porsche-- he said he could not tell me what the problem was of yet, but suspected electrical and wants me to bring it back next week. Any other ideas? Anyone have a similar experience?

Your help is appreciated!

I would check the throttle to ensure that its at WOT when the pedal is floored.

Provided that the plugs, wires, cap & rotor are all in excellent condition and the fuel filter is new, I would have your mechanic check out the cat. They can get plugged up and that certainly fits your symptoms.

Jagshund · 08-22-2008, 09:11 PM

Oops! I made a fox pass. Welcome to "the bored".

VroomGrrl · 08-23-2008, 05:22 AM

Welcome!

I am like the court jester of the forum, all stupid questions and accidentally brilliant answers, delivered while dancing around in a pointy hat and shoes!

Let me try my skills out on you.

Could the PO have adjusted the rev limiter down to 4500?

Boise911 · 09-15-2008, 07:45 PM

What is the "Cat"? Catalytic converter?

Boise911 · 09-15-2008, 07:49 PM

Thanks for your response. I take some pictures and will get them uploaded soon.

Boomtown Rat · Boomtown Rat's Garage

Hi there! Have you replaced the DME yet? Trivial part (under your driver's seat) that can cause the weirdest of phenomena. I had one go bad in my `86 Cabriolet (now sold) a couple of years back and it started the same way that you're describing your problem over 4,500. It just got worse and worse, until the car wouldn't accelerate at all. Switched out the DME (cost something like 50 Euro and took 30 minutes) and all was well again. Good luck!

Boomtown Rat · Boomtown Rat's Garage

Hi there! Have you replaced the DME yet? Trivial part (under your driver's seat) that can cause the weirdest of phenomena. I had one go bad in my `86 Cabriolet (now sold) a couple of years back and it started the same way that you're describing your problem over 4,500. It just got worse and worse, until the car wouldn't accelerate at all. Switched out the DME (cost something like 50 Euro and took 30 minutes) and all was well again. Good luck!