3.2 conical filter revving issues????
 

I just bought an '84 Carrera 3.2. Car won't rev over 5k. Checked condition of speed sensor, brand new. Need to still check gap. The previous owner installed an MSDS conical type filter with an adapter that attaches directly to the AFM. I've had past experiences with the same style AFM in an 89 BMW race car. It was a given that the stock air filter box should be used because it has a built in cone that smooths the air before the air enters the AFM for optimal performance. Has anyone has issues with aftermarket air filters that ditch the stock air box?

No. I had exactly that. 3.2l with aftermarket, round air filter. An expensive adapter to make the transition from round to rectangular as smooth as possible. Engine was very rev happy. I am sure a cheaper adapter would not have made night and day difference.

Running now again a round filter but connected to an HFM.

Have you verified that the throttle linkage allows for full throttle? (not at the pedal, inside the engine compartment)

No, I haven't. The engine pulls hard and then starts missing at 5,200. Almost like a rev limiter.

Hi as Zippy said ........check you full throttle with the engine off.also have look at your distributor rotor .If somebody have used some king of funny t rotor..
Also check if you have an cruise control sometimes the two little screws which hold the bracket have missing washer and the linkage gets stuck..there is an earlier post here about this problem...

Ivan
last thing, fuel filter.... have a look at the date on it if it is not too old...

I ran the fuel real low in the car today. I was going to remove the fuel sending unit and check the in tank filter tonight.

I'm overly skeptical about the speed sensor on the flywheel. It's brand new looking. Ive read that the gap is critical. I was going g to try swapping the speed sensor and the reference sensors to see if that helped

Hmm that would not make the car not go over 5000...really.Look for mechanical problem..first..

the suggestion about the fuel filter i gave you is because i know not to many mechanic change them regularly. On the filter is a date of manufacture.....anything over 1-2 year is too old -replace it..
ivan

Too much gap at the reference sensor and it'll crap out at higher rpm. Clogged cat/fuel filter will do the same.

The MSDS filter is a very good product. Marty knows a thing or 2 about Porsche's. Its not causing your problem.

I ran the fuel close to empty last night. I removed the fuel sending unit and looked inside the tank at the in tank screen. The entire fuel tank looked immaculate inside. The fuel filter was changed in Jan 2016 and has about 1500 miles on it.. Being that the tank is so clean, I doubt the filter is the problem.

The past service records show that a little over a year ago, the reference and speed sensors were both changed along with the mounting bracket because the mounting bracket failed causing one of the sensors to contact the fly wheel.

I swapped one sensor for the other with no avail. I want to check the gap later today.

I wonder if when the sensor contacted the flywheel if it wore down the sensor screw on the flywheel itself.

I want to pull the plugs later to check them out as well. The plugs were changed last year as well.

Also did you check you full throttle yet?Step on gas and somebody in the back will look how far you linkage opens

Ivan

I didn't. But I did check the TPS at the DME. Checks out ok.

As well I think it mechanical.
How are you going to check the gap on the flywheels sensor?
I believe the only way to do this is to use an old sensor with a spacer glued to the end. Or separate the motor from the transmission.

I may have an old BMW sensor laying around to check the gap. I found a washer that's between 0.8-.9 mm

It was the speed sensor gap. Set gap using a washer on the end of the sensor. Engine revs beautifully!

good job .....and now we all know for the next time...congrats

Ivan