missfire on gas shut off when off gas

[98_tsi_awd]

so ive been having probs with my 98 tsi its been running like shit for about 2 weeks now and i parked the car after she wouldnt wanna idle at stop signs or lights.and while driving it would buck and sound like it has a studder box at 5k...ive replaced the fuel filter crank sensor and checked my plugs and wires and it all seems fine....so i bought a walbro 255 fuel pump from a few dsm kids in the area it was almost new used in a car for a few months and then they parted the car out....i installed it thinking maybe my old pump was bad and not giving my car fuel...well i started it up tonight and the car was backfiring and wouldnt stay running if my foot was not on the gas at a steady rpm it would pop i was thinking a missfire?

so i guess im asking what should i look into to solve this? im new to the dsm's and the whole turbo setup

is it my plugs and wires or is it somthing stupid like bad gas because it all happend after i filled her up? any help would be great im basically in a stand still now

 

[shinzon]

Have you done a boost leak test? Do you have an adjustable fuel pressure regulator? You'll need one with a 255 as it'll overrun the stock fpr. Whats the fuel pressure like?

 

[98_tsi_awd]

got the car to idle but was still hesitant....blue smoke from exhaust and from turbo area....bad turbo?

 

[asb2106]

sounds like your burning oil with the turbo..

But those problems are very similar to my problems, that "stutter box" feel, I get it as well, but if I go WOT it can happen as early as 4k, and as late as 6k if I rev up at half throttle.

Ive replaced alot, and I find myself running in circles lately..

@shinzon, my wally and my stocker both do the same thing, and from what I can tell the stock fpr is going pretty good with the wally.

Ive been thinking coolant temp sensor lately (got a new one coming in tomorrow)
If the ECU does not find out the temp increase it will continue to run real rich, which is the conditions im getting.

 

[98_tsi_awd]

so you arent using a aftermarket fpr? i haveone justhaent found the time to set it up....and im going to try replacing the stock turbo with a 16g and see what happens..........im also rinning in circles