Tuning Troubleshooting

[94Jettameowpsst]

Well, i have a 90 talon tsi w/ mods in profile. I was driving my car today and did a couple launches and donuts on this dirt road, but thats not the problem . The problem is for some reason when i went to pick up my friend about 45 minutes later, my car wouldnt rev past 4k rpm and it would jerk and backfire. So i leaned out my afc....it pulls a LOT harder than it did before, but i have NO idea why my settings were mysteriously too rich. I dont have any boost leaks and if i do, its nothin major. Now when i say i leaned it out im talkin about 10-15 more %. What the hell could have caused this cause im kinda confused???

 

[steve]

What have you done so far to try and track down the problem?

Steve

 

[CanadianTSi]

It's a boost Leak.

 

[94Jettameowpsst]

Well i just leaned it out a whole bunch, but my boost controller is set to 20, and thats where it holds till redline. I dont know what the problem.

 

[94Jettameowpsst]

Update: I took my car for a ride again to see if it may have changed as abruptly as it did originally, but to no avail, it didnt. But, it honestly feels like it did when my factory fuel pump went bad. My pump isnt rewired, but i never had a problem with it before. It cuts out and jerks, but it feels like its getting way too much fuel, and the only way it'll run under boost is if i lean it out a lot as i said in my first post. Any input would be great.

 

[94Jettameowpsst]

Not bumpin my thread, but i did just think of somethin while readin through another post. If you read my mod list you'll see that i have a walbro 255 and a stock auto fpr t'd into the intake mani...if ya dont know that yields 40+psi of fuel pressure (w/ stock pump). Now, do you think i could have blown the stock fpr out? I did hit rev limiter a few times when i was doin donuts....anyone think that could be the culpret?