Lost usual acceleration at high RPM

[rigol2000]

Goodmorning!

I have a performance issue I'd like to bounce off ya'll. For several days now, I've lost my usual brisk acceleration at higher RPMs on my 95 MTX. The secondaries open between 3k & 4k, but I do not have the usual boost of power. In fact, it takes a while to get up into the RPMs. Lower end RPMs seem fine.

In it's recent history, the car sat idle for about 5 months waiting for me to replace the crank shaft pulley that had separated. A few weeks ago, the pulley was replaced and it was running fine. I had the usual power through the whole RPM band for several days. Then one morning, I got in, started fine but I did not have the power as stated above.

I bought this car with several modifications. Those include:
73mm MAF
SCT chip
Y-pipe
Dynomax exhaust

I checked the air filter and it is clear. I removed the SCT chip and there was no difference in the performance. There's no oil in the plug wells. It seems to run great except for the reduced acceleration.

I checked the engine codes and got these:
KOEO
511 - No power to PCM pin 1 or bad PCM (Probably because of the SCT chip)
KOER
167 - TPS (I can never seem to goose the throttle enough)
255 - Knock sensor not tested

In the research I've done here, I see that I may want to clean the MAF, though I haven't found how. I'm hesitant to just spray a cleaner all in it. Also, maybe clogged CATs. I need to hit it with a rubber mallet. If it rattles, then it's bad? I was also thinking maybe I have clogged injectors or fuel filter. How do I check this? SHould I pour some injector cleaner in the fuel tank?

Thanks for any help.

Chris

 

[shocrates]

It could be the things you mentioned. I don't know how to clean a 73mm MAF. I'd change the fuel filter for good measure and pour a can of Berryman's B12 in the gas tank. If you hit the cats with a mallet and it sounds like there is something loose in them, they're bad.

You mentioned recently changing the crank pulley. Did you attain the proper torque on the crank bolt? If the bolt isn't tight enough the timing sprocket will rotate on the shaft throwing off the timing.

 

[whiteguy3]

My guess is most likely TPS. When the TPS usually goes bad it doesn't always trip a code, but in this case it did. The TPS might not be recognizing that the thottle body is at WOT and therefore it won't feel like it's at WOT!

I know I've had the TPS go out on me a couple of times. Along with freakin' ******** shifting it felt down on power sometimes. But, if that doesn't fix it then take the advise of others and check your cats, and also just clean the MAF sensor with MAF Sensor cleaner that you can get at your local parts store.

 

[Kens1992mtxSHO]

Clean your MAF, throw a can of BG-44 or Berryman's in the gas tank, clean your air filter, perform an induction service (Seafoam or BG) learn to goose your throttle, run codes and report back.

*EDIT* Could just be you need a 60k

To clean your MAF remove the MAF from the housing. You'll need a torx screwdriver. I think it's a 20. Be extremely careful when removing the MAF from the housing not to touch the filament. Spray liberally with MAF cleaner. Let dry and reinstall.