advice needed

[jbwalt3]

Hello everybody, I am a newb as this is my first post, however I have been reading on here for the past month or two since I have owned my 99 WS6.

I don't even know what to run the search as for my problem, so please take it easy on me.

I have a M6 LS1 and my main concern is with a lack of acceleration from time to time right around 2500-3500 rpms. More often then not, the problem occurs when my car isn't warmed up. After its been running a while it goes away for the most part but not totally. The engine doesn't bog down, but it feels like the car isn't accelerating like it should, I can run through the gears fine at lower rpms, but once i hit the upper 2000's it does it. Remember it is only time to time, and when it does it, itll come back to power again at 3500 or so rpms. For some reason theres a window between 2800-3500 where it almost feels like there is transmission slippage or something. It is worst when coming around a corner and getting on it in 2nd. 2nd and 3rd gear is where I experience the problem most. Has anyone heard of this?

Thank you very much.
Justin

[Steve Crowe]

That is a tough one but I've heard others mention similar before.

Although I doubt it will fix it the first thing I'd do is reset the PCM - unhook the NEGATIVE battery cable for at least an hour, reconnect and retry. (It will hesitate to start on the first crank if the PCM reset properly)

PLegs &/or plug wires can also cause some strange behavior similar to this as can a sticky EGR valve.

[Eric @ W.A.R.]

Between the 2800-3500 rpms when you see the problems, what happens when you floor it? Do the rpms shoot up but you go nowhere?

I once saw something kind of similar and it was attributed to a slipping clutch.

[jbwalt3]

This morning I installed a new battery (old one went bad), reset my PCM, and put in a Fram filter (had a K&N).

I had first thought it was def. tranny related, but then over analyzed it and thought maybe maf is bad, maybe this, maybe that. I haven't had a chance to run it since resetting the pcm and putting a new battery in it, and i suppose its possible my maf is ruined from the k&n that was in it.

However, I am having a local transmission shop check into it in the morning to double check. I first thought clutch slippage- but if this is the case, why can i run through the gears flawlessly, no problems what so ever other than this?

[sunsetorangess]

I had an issue with my k&n I just pulled the filter and tossed it into the trash and moved up to a fram. The oil from the filter gets on the maf, which causes issues but its a simple fix, goto your local parts store and pick up some crc maf cleaner, then pull the maf, spray it down real good, then put it back on a drive around.
J

[Eric @ W.A.R.]

I don't see issues with the MAF often caused by the K&N, however that's not to say it hasn't been seen before. Clean our your K&N and try cleaning your MAF first. Do you still have the stock MAF? De-screened?


After cleaning it, reset the PCM and give her a drive to re-learn the curves. Hopefully this simple fix will help.

Good luck and keep us posted.

[9T8W66]

Yeah I'd have to agree with the others probably a bad sensor or dirty MAF. Although plugs and wires may solve the problem aswell.
In my experience if it was the clutch it would continue to slip well above 3500rpm not the short wndow you are describing. Mine clutch only slips occasionally and only at high rev's under WOT, but I also have 115K on it.