Hi, guys;

I replaced the turbo a few months ago and it started choking when I pressed on the accelerator to the floor. Then the software was re downloaded and seemed to be fine. I just installed a new clutch and flywheel and yesterday I installed an ECU with an APR chip (the basic chip upgrade...no fuel mods, no diverter valve changed, no injectors upgrade).

Since I installed the ECU, obviously I feel the car has a lot more power, but it's not managing it very well. The car runs well until I floor it, regardless on what gear and how many RPM's, the car starts shaking and coughing until I give the gas pedal a break. It even triggered a misfire code and the check engine light came out. Now the light has been reset, but the problem still persists.

I need help: do I need to have the software downloaded again? The ECU's are compatible as per definitions via several sources. Do I run any risk with the APR chip if I have the shop download the original software? The chip and ECU was used, could I have a faulty ECU/chip?

Thank you for any pointers, for taking the time to read and for your help,

Fabian.

 

sounds like its misfiring as per the code you pulled. Common causes are plugs or the coil packs. Possibly a loose or cracked vac line too.

 

im gonna agree its a either a vac leak leak or a small misfire in one of the cylinders.

 

...what's weird is that I replaced the spark plugs less than a month ago and the car was running fine. When I replaced the turbo (about 6 months ago), the car was doing the same thing...almost as if it was boosting out of proportion. The car doesn't startle until I floor the gas pedal...I wonder if the new programming of the chip is affecting the way the turbo is performing...any thoughts?

 

Its probably your coil packs then. I dont know anyone with an A4 who hasnt replaced them.

 

When you install the ECU did you do a TB alignment by turning the key on for 15-20 seconds before you start the car?


McGovs1.8B5 - Coil pack issues are just a 2001+ problem, not really a problem on any of the years before that. The ndbw cars usually have the controller go bad, 2000's dont have any coil pack problems since they have the best coils Audi has ever used.

 

Oh didnt realize that, thanks Mike

 

I didn't turn the key on for 15-20 seconds. What does that do to it? Also, I checked the coils, the modulator, the spark plugs, everything is fine. When I switch back to the original ECU, all misfire problems are gone. I'm wondering if I have a bad used APR Chipped ECU at this point, but I'll try turning on the key for 15-20 seconds before starting it.

Thank you for the tips,

Fabian.

 

The throttle body has a throttle position sensor, when you unplug the battery or unplug the ECU that sensor resets and the first time you turn the key on it reads its position with the motor not running. If you start the car right away the reading will be off and the ecu will think the throttle is at a different position then it really is.

 

Thank you for the tip. I did it and it made no difference...on the contrary, the misfire triggered the check engine light, even without turning the car on. I was told the 20 sec. rule applies to newer models (after 1998.5), on the older cars 1998.5 and older, you can even change the programming while running.

When I replace the ECU, the car runs a lot better (though I can still detect a very minor level of misfire) and the check engine light turns off immediately.

I had the ECU checked by an APR specialist and the chip is fine, it was an older software (2000) and it was upgraded with the current software (2010), but according to them, the chip is doing what's supposed to.

Next I'll try changing spark plugs to the original NGK's (instead of the Denso Iridium I currently have) and if it doesn't work, replace the coils and the modulator.

Any tips, thoughts or ideas before I pull out my wallet AGAIN?

Thank you for your help, gus, I really appreciate it,

Fabian.