Whisper

iTrader: (12)

I had a shop put plugs in my car today and fix an obnoxiously loud vacuum leak and expected that to fix my flatspot/hesitation/surging issue in the 2000 rpm range, especially around 2400 rpm. The guy also said the car was throwing a feqw lean bank codes but he cleared them before putting in the plugs. This didn't resolve the hesitation issue. Im going to clean the MAF with contact cleaner later on today when weather permits but what else could the problem be? They tested the oxygen sensors as well and found no problems, plus I haven't noticed a drop in gas mileage. Any ideas?

ae13291

iTrader: (8)

could possibly be a cracked spark plug but im not sure, and you need to double check on the o2 sensors. also check the mass air flow sensor

wssix99

iTrader: (5)

Try the MAF. A dirty one can cause you to go lean at higher RPMs.

Wiktorek25

mine has the same problem, under like 25% load only though. Car will run fine, then hit like a wall around 2000-2300, then after that it picks up like normal again

Wiktorek25

ttt...

drummydummy

iTrader: (1)

anyone have anymore input on having the same problems??

I've been trying to resolve my RPM hesitation for the last 6 months and have had no luck yet.

I've recently given her new ACDelco plugs, MSD 8.5mm wires, a fresh fuel filter and fuel system cleaning, cleaned the MAF, the O2 sensors are working to the best of my knowledge and it STILL feels like I'm letting off the gas and getting back into it around 2400-3000 RPM.

I would figure this is computer/PCM/tuning issue. I didn't think a vaccuum leak would create such a BIG surge in the powerband as the only vaccuum leak I might have would be from ripping out the AIR system. however if I don't have cats anymore the AIR system should be useless anyways.

This has been bugging the **** out of me for too long!!!

I know there are at least a hand-full of other people on this forum that have experianced the same issues. It seems everyone is told a 'tune-up' will take care of it but seems to never be the case.

ANY INPUT AT ALL?!?!?!!?

chrysler kid

iTrader: (14)

you still filling up with 93 octane? next time you drive past pep boys or autozone buy some lucas oil octane booster. your car has like 140k on it, it could be gunked up valves or just about anything since you dont have a dyno graph to show your a/f settings

drummydummy

iTrader: (1)

I run NOTHING but 93 octane, and I have regularly done fuel system treatments and fresh fuel filters at least once a year. I've also just recently put some octane booster in it when I put the MSD's and new plugs in.

I figure when I put my 4.10's in I have to get the car tuned so maybe whoever is doing the tune can figure out what is causing the hesitation.

ws6onSLICKS

the mass air is bad. i had the same problem in my 00' T/A. Its like the motor hickups right? i just thru the MAF away and tuned the fuel/air with HP tuner. now i dont have to rely on those sorry MAF.

FiredUpZ28

Its possible if the check valve in the air pump goes bad it can create a lean 02 signal by injecting air when its not needed. But as far as I know ours turn on and off by the PCM so maybe a loose wire.