Im running a drag III turbo kit t3/t04e on my LS and i had the same kit on my GSR motor before this. When im driving once in a while the car will hesitate and jolt and sputter like the motor is choking what could the cause of this be? Im running FMU, missing link, ericks racing fpr set at 50psi stock fuel pump and stock injectors, a friend of mine told me it can be the fuel pump has to be upgrade. Also my gsr motor was able to boost 5psi no problem but my LS would only boost 4psi max! is this because my vacuum readings is around 16hg at idle....i just tightened up all the charger pipes and check for vacuum leaks, but i do not seem to find out the problem. please help someone!!! thanks

 

Sounds to me like your injectors and/or FMU/FPR? I'd upgrade to better Fuel management if I were you. Just my .02

 

yeah... but why wont it hit 5psi? my gsr did with the same kit? also i hear rattling noises through my inside my exhaust some say its detonation when i searched

 

fmu with 50 base psi sounds like allot of fuel to me.

Landon

 

should i put it back to stock 43psi? with the vacuum off?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ryan819 &raquo;</TD></TR><TR><TD CLASS="quote">should i put it back to stock 43psi? with the vacuum off?</TD></TR></TABLE>

Off-hand I don't know what the GSR fp at idle is supposed to be, but 50 seems a bit high (w/ vaccum off) for an LS

 

If understand correctly it is difficult to even achieve 4-5 psi. Check your exhaust...cat may be clogged, or exhaust to small. If you can't run higher boost because of a lean condition, deff. upgrade the fuel system...

 

I have 3" mandrel bent all the way back from the downpipe.... so there is no cat or resonator. im going to try my old FPR and see what happens. thanks

 

alrighty, well good luck, If i can think of anything else i'll let you know...

 

It's recomended that you run an Inline Fuel pump with an FMU, in order to support the high fuel pressure as a result of the FMU. I think this is your problem, from your post obviosuly the Intank pump is stock, but you never mentioned an Inline pump. Sounds like your not getting enough fuel, anyone else agree?

What spring is in your wastegate?

When i did my install I ran Fmu with Intank walbro 255 hp for two months and it was fine, I think for low boost an intank is fine, but I only did that because I was going hondata within a couple of months.

 

hmm im having somewhat of a similar problem... with somewhat of a similar setup...

i have my D16 setup similar to his except i have an inline... and i can boost 5psi fine when im in boost..

i had some hard hesitation when i first put my setup in... and it was all the time... even in boost.... so i cleaned the missing link, and it fixed most of it... got new plugs gapped to .032...helped a bit...(i think i need to go smaller) no at times it runs like a stock car... but then at times it doesnt...

my problem is shuddering and hesitation either in the transition into boost at light throttle.... or at about 10inhg of vacuum... the car acts like i let off the gas completely....it happens at about 2500-3000 also... never any sooner... and never any later... cause once i get past 3000 is fine

setup up is - 5psi
vortech fmu 12:1
missing link(cleaned twice)
msd inline fuel pump
walbro intake 190gph fuel pump
stock fpr
stock injectors

 

this is wierd but i was able to hit 5psi no problem when i had this kit on my previous motor... and i noticed that my wastegate isnt shooting out black **** all over my radiator support... can it be that i vacuumed my wastegate wrong? i got vacuum from the charge pipe becaus there is a nipple on it and i put it on the side of the wastegate. before i had it T'd with into the charge pipe and 1 hose going to my other vacuum sorce on my motor

 

DUDE YOUR RUNNING TOO LEAN ADD A BOOSTER PUMP UR BE STRAIGHT, OR U CAN RUN AN 255 IN TANK PUMP AND U'LL BE FINE ALSO, DO A PLUG READING. WHAT COLOR ARE THEY IF THEY ARE WHITE TOO LEAN, IF THEY ARE A CARMEL COLOR PERFECT, IF THEY ARE BLACK TOO RICH ,WHEN I SAY LOOK AT THE COLOR U ARE TO LOOK AT THE PORCALIN OF THE PLUG TIP