sr stuttering

[SLEEPERracer]

was wondering if you guys have any idea y an sr would studder? it was running fine and its all stock except for front mount and bov. well it only studders when i hit boost. like it lacks fuel or something. only thing that was changed was the previous owner switching out the ecu for another, and ever since then had the this problem. any help would be greatly appriciated. thanks in advance.

[IRN]

if it happened right after the ecu swap then try swapping the ecu to a known good one lol

[ocn]

do you have a walrbo fuel pump if not thats your problem, also chek you vacum lines.

[AllMotorS13]

how would a fuel pump make it stutter? i'm assuming your on stock boost if you don't have a walbro. the ka pump can handle stock boost. change the ecu first, obviously. if that doesn't do it, check for boost/vacuum leaks. do the tap test on your MAF and wiring. try unplugging the O2 sensor and see if it goes away (that's what mine was). plugs in good condition? coils may be suspect. there's a ton of reasons for a stutter under boost. does it do it under full throttle, partial throttle? Engine cold or warmed up?

[Z33dori]

yea my car is having this trouble too.....

as soon as it starts hitting boost it would start sputtering and breaking up...i thought it was coil pack or spark plug but i have changed out both so its niether of those, so my next beat im guessing is to try and get a another ecu? fuck

[AllMotorS13]

yea my car is having this trouble too.....

as soon as it starts hitting boost it would start sputtering and breaking up...i thought it was coil pack or spark plug but i have changed out both so its niether of those, so my next beat im guessing is to try and get a another ecu? fuck

read my post above. i just diag'd this on my own car. my ECU was fine.

[Mi Beardo es Loco]

I would check the MAF. I've come across a rash of bad MAF's lately. Just a hunch.

[BeasT_MoDe]

sounds like a boost leak.

[deuceforty]

ive got a buddy who is having this same problem...

his is a bit different though, its a completely stock SR, sidemount, stock diverter valve etc.

hes ran through the entire wiring harness, changed the TPS, plugs, maf and a few other things.

when his car starts, he will have 3-4 good pulls, then it will start to stutter at boost. heres the catch, if you turn it off, then back on, you will get 1-2 more good pulls.

here is yet ANOTHER catch.

car will build full boost in neutral. you can sit with the car in neutral, rev it, and boost will build to 10psi... how can it boost if there is virtually no load on the engine?

its got us stumped