Flatspot at 3000-3200 rpm
 

So I've been doing some work to my 2000 Boxster, some that was needed and other stuff just preventive maintenance since I didn't have much previous service history on this car.
Had a cel which ended up being a Maf, changed it and no more cel.:cheers:
Warm starts always gave me a rough idle for 30 secs and misfire code, so changed all coils and plugs, problem solved.:cheers:
The car has 50000 kms and was now running perfect through the entire rmp range.
Lastly I decided with all this work done I might as well clean the TB, so I did, it wasn't too bad and no excessive oil from AOS that I could see, but now.....it has a noticeable flat spot at around the 3000 rmp mark, mostly noticeable at half to three quarter throttle.:mad:
I did the E GAS reset, but no change.
I also read that the caymans seem to have this issue and it's quite normal, but mine wasn't doing it until now.
Any thoughts on this?

Am I the only with this problem?

I sometimes have a flat spot around 5000 rpm at wide open throttle. I have changed the MAF, AOS, plugs and checked for vacuum leaks. I noticed when I disconnect the battery to do electrical things, I don't seem to have the flat spot when I hook it back up. It does seem to come back after a while though.

I don't have any active or pending codes using an Actron scanner. I hope to get a Durametric cable this winter. Maybe that will help me figure it out. Sorry I couldn't be more help.

Thanks for the reply, the only thing I can think of is since this happened after cleaning the Tb, I must have left some dirt, residue somehow, or created some sort of vacuum leak on installation. I'll clean it again, and also try disconnecting the battery, maybe it does need a reset.

You can search for a vacuum leak by spraying carb cleaner that is combustible around your intake area and see if it changes idle momentarily.

In most trouble shooting issues where something has been touched
I focus on that area first.

It would seem too much of a coincidence otherwise to just start a new problem.

You might also try cleaning your MAF


Mike

Update
 

I checked for vacuum leaks and none were found, so I decided to clean the TB again, and since my hands were in the mud I also cleaned the MAF (this new Maf was installed about a month ago) retightened all the connections again, went for a test drive and it's smooth again through the entire rpm range.
So I'm glad it got resolved, but I hate that I couldn't single out the problem.

Is the new MAF OEM or aftermarket? IIRC some people have had issues with aftermarket MAFs.

Hmm.......yup, aftermarket. I if happens again, this time I will just clean the MAF and maybe able to pin point the source.