Thread: Drivability Problems

Check for a misfire.

does it do it on hills or anytime you give it 1/2 throttle?? low rpms or all rpms??

my car will start to jump rpms a little when going up hill in 4th and the torque converter is locked around 1200 rpms it will jump around a tad. but it does not shake anything. i just let off to relese the torque converter and it stops.

my problem is my transmission, maybe the torque converter sliping.

sounds like a bad coil pack, or wire, or plug, or even the ignition control module. if you've driven it for 20k like that...you've probably scored a cylinder by now.

start by checking for a bad wire or fouled up plugs, if they're all good then...

take the packs off and check to see if the primary and secondary resistance is in spec, on EACH pack. advance auto parts can help you with that. they can also check to see if your ignition control module is bad.

make sure you don't cross any wires when putting it all back together.

you're probably getting bad gas milage too aren't you? how many miles on the car? any mods?

My guess is worn valve body in tranny. Mine did the same thing when I bought it. Between the DIY shift kit and tuning it with the PT, I don't have these issues anymore.

Taken from here:

Tach bounces up and down a few hundered rpm while cruising in lockup:
Another common problem / concern of this transmission and more pronounced with added engine power or higher mileage. This generally happens when the valve body has excess wear in the TCC valve area. Excessive fluid leakage in this area of the valve body causes TCC apply pressure loss and can lead to uncontrollable TCC operation which causes the engine rpm to bounce up and down a bit. This problem is noticed most after driving a while and speeds between 42 and 70mph and in 4th gear. There are other causes to this problem that can be from worn or shrunken teflon seals on the input shaft, a bad o-ring on the input shaft that seals in the torque converter, a faulty torque converter clutch, and even a bad pressure control solenoid. Another common occurance is a worn out sleeve in the channel plate that supports the input shaft. When this sleeve wears the input shaft will get chewed up where the sealing rings are and cause problems. Commonly code P0741 will be found in the pcm memory as a stored code and is described as Torque Converter Clutch Stuck Off. When this happens adaptives shifts are disabled, TCC operation is disabled, and 4th gear can be disabled. Generally a new or reman / repaired valve body will correct this condition and a new EPC solenoid is always suggested as well. The TCC/PWM solenoid is rarely ever at fault and I am yet to find one bad. Again the valve body is the common cure BUT not always the culprit and certainly not the whole problem after this has been happening for a while. Any time a torque converter fails there will be debris going back into the trans. There is a pressure relief valve in the channel plate that will collect debris from a bad torque converter and reduce cooler flow, cause trans to run hot, and greatly effect TCC operation and can destroy a new converter in a matter of miles if this isnt carefully inspected or upgraded. The best way to verify proper operation as commanded by the pcm is with a scan tool by viewing TCC slippage rpm, TCC duty cycle, EPC data, and checking any codes and making sure the engine is running properly and a misfire is not a false sense of a torque converter problem or shudder.

Originally Posted by ArmyMech651

about 5,000 miles ago I put 3 MSD ignition coil packs

take them off! the stock coil packs are better than the MSD ones.

i have a powrtuner for my 04. hptuners also works for 04-05s. raising my torque converter lockup speeds cured the majority of my problems.

for the powrtuner or hptuner??? the powrtuner is no longer sold. for hptuners just buy the gm suit. its 500$ tho. the only issuie is the 06 and newer grand prixs. with your 04 your fine.

HPTuners.com >> Performance At Your Fingertips

or just find someone with a tuner and have them tweak it some.

throttle position sensor maybe?

Originally Posted by 01gtspecial

throttle position sensor maybe?

If it's the TPS sensor he'd continue to go the same speed even goin up a slope. & if shifting into or through reverse there would be an ugly clunking sound while shifting.

DHP powrtuner. i think there is one forsale for 300$ right now. its not as user friendly and there is not as much support for it. for the hptuner all the pro version is, is a place to hook up your wideband and data log that too. if you want that option go for it, but i dont really think you need it.

depends. alot of people run msd's with no problem. but others have problems. its all in the wiring up from what i have gathered. but there is nothing wrong with the stockers.

The amount of spark a coil can produce is limited by computer. There wouldn't be any performance gains at all, unless you have bad coils.