Cant accelerate hard. whats the problem?!

[Addicted2Kouki]

Just upgraded maf, injectors, & got a retune for my chipped ecu.

The car idles and revs in neutral fine.
When I drive the car, it is fine until I accelerate hard.
Anything more than half throttle with load applied,
makes the car backfire and sound like i hit some kinda limiter.

My question is.. Can these upgrades but no change in boost level create spark blow out? The ecu chip tuner said this was a possibility.

Im thinking its the tune.


Feel free to leave your input.

Upgraded from
370cc injectors to 480cc injectors
N60 maf to Z32 (n62) maf
&ecu chip to accomodate to these upgrades.

[s13silvia123]

maybe boost leak i have about the same problems but a different setup then yours but it most likely will a boost leak

[!Zar!]

I don't really think any setup on a sr will have blowout if you are running sub 550cc injectors.

But I could be talking out of my ass. Who knows.

[Chrischeezer]

Whats the air/fuel ratio when this happens?

[Addicted2Kouki]

I don't really think any setup on a sr will have blowout if you are running sub 550cc injectors.

But I could be talking out of my ass. Who knows.

Its actually a KA-T. :wiggle:
Sorry forgot to include that tiny detail.


Gapped the plugs to .30 and now it runs a lil better but it doesnt feel like its accelerating how it should.

[Chrischeezer]

still have the same problem after the gap change?, or is it now a different problem?

whats your wideband reading when its breaking up?

[Addicted2Kouki]

still have the same problem after the gap change?, or is it now a different problem?

whats your wideband reading when its breaking up?

i thought the problem went away..
but its more like the gap change made it a lil better?
as in it didnt break up as early.

i dont have a wideband at the moment. :wtc:

[buentellomma]

what fuel pump are you running? how old is it?/ whats the fuel pressure set at?

[Om1kron]

dyno asap.

[Addicted2Kouki]

what fuel pump are you running? how old is it?/ whats the fuel pressure set at?

walbro.
about a week old.
stock fpr.

dyno asap.

dammit. i know, i just missed a dyno day in my area by about 3 days
because my car wasnt running (waiting on the tune).

[!Zar!]

Check your timing?

[R@ddy]

my SR, i know yours is a KA, did the same. it turned out to be a shitty engine harness. i switched out and it runs like a champ!


less than half throttle smooth all the way up to 6k+

full throttle it was smooth til like 4k rpm: vrommm braaa paaaap paaap. you know what i mean? kinda like a rev limiter. hope it helps ;)

[Addicted2Kouki]

Check your timing?

The infamous Steve Shadows set my timing like last week.
should be spot on. lol

my SR, i know yours is a KA, did the same. it turned out to be a shitty engine harness. i switched out and it runs like a champ!


less than half throttle smooth all the way up to 6k+

full throttle it was smooth til like 4k rpm: vrommm braaa paaaap paaap. you know what i mean? kinda like a rev limiter. hope it helps ;)

LOL engine harness ehh?
interesting description.
SOUNDS EXACTLY LIKE MY PROBLEM AHHAHAHA

hrm.. funny you should mention harness.
i was messing with my conversion harness to my ecu today
and my car mysteriously turned off.

I think i know where to start looking.

[Chrischeezer]

duuurrrrrr....


lol

[M4Rl0N]

Funny thing is im having the same problem and everything i have is stock.
My harness is shitty to hell and my motor mounts are blown, so im replacing the mounts to stop the crazy engine shaking but i might look into my harness also....thanks

Good luck with your car.