when car is cold and im at idle i give it gas and its like the car wants to die

[awdtalon21]

Ok i have a 92 talon tsi built bottom end evo3 16g 3in exhaust 780 injectors gm maf-t walbro 255, now when the car is cold and im at idle i give it gas and its like the car wants to die on me, after it is warmed up it does not do that any more but when im driving it and i hit 20psi the car stutters really bad. it seams to work better if i dont give it full throttle while boosting.

My next problem is that the tach does not work but it shows up on the logger. i have the white wire hooked up on the cas (the black wire)

I have checked for boost leaks there are none.

 

[5150DSM]

Do you have an AFPR? You could be experiencing overrun on the stock FPR causing a rich condition. Also, are you sure the MAFT is set correctly for the 780's? Recheck your MAFT settings and log some info if you are not knocking in the upper rpm's, maybe try to take away a little fuel to see if she smooths out.
Good luck.

 

[NATAS]

If it's not a boost leak then it has to be fuel. 780's are a little big for what you have especially mated with a 255lph fuel pump and all you're using to try and reel in those injectors is a maft. I'd bet dollars to donuts you're running rich. What does your logger say? What are your long term and short term fuel trims? How about the o2? Do you have an AFPR to help in reeling in the fuel pump? I would say downsize your injectors to the 550cc range or get a real tuning program like DSMLINK. I've had nothing but problems with the MAFT especially with big injectors. You could also get a chip made for your ECU since it's a 1G and that's fairly cheap and easy to do. What is your IDC ; it has to be low.

The easiest solution would to be to sell the 780's and the MAFT and get some EVO 560cc injectors, an AFPR if you want to keep the 255 and don't have one, and an AFC which is much easier to use. In fact, AFC+Logger is downright cake to tune with. If you have the dough just get DSMLINK, learn how to use it, and reel in your fuel supply as soon as possible.

If you need a milder fuel set-up for a 16g I have one available that includes evo9 injectors, afc, and evo8 fuel pump that I'd sell cheap. Good luck man.

 

[awdtalon21]

well there was a 190 pump in there before and it still had the same problems. i will try to get a log up a soon as im done changing the wheel bearings. As for the fuel trims a have not seen them move at all the past week since i have had this car up and running. and im not sure how to tune using the maft, i have read up it but i still dont really understand the 4 knobs, i think the first one is base setting but im not sure. i do have an afc but im not sure if i wanted to put that in or not. and im still lost about the tach not working. i have tried 3 other clusters too.

 

[5150DSM]

Start here for your MAFT tuning info... http://www.fullthrottletech.com/forumdisplay.php?f=6

Also check out the tech articles section under tuning for more in-depth guidance. One thing for sure, if you don't have an AFPR tuning is going to be difficult at best using the 255pump. Non-linear fuel curves are nearly impossible to tune consistently and correctly.
Good Luck.