car bucking

[simpson_eh]

HI all

i have an issue with my 5sgte, when accelerating the car is fine but when i let off or even when im driving normally if i give it light revs in any gear the car bucks, press it a bit more and its fine, accelerates without issues

so its just normally when cruising (not in the wrong gear before anyone suggests that) does it in all gears. fells like injectors cant make up their mind to stay open or closed

walpro in tank pick up pump to swirlpot and a 044 to rail 850cc injectors
apexi power fc

many thanks

Tony

[oxide_mr2]

idle control or worn engine mounts possibly?

[MartinF]

Has it started to do this recently or always done it?

[simpson_eh]

Just recently like last three days since the. 2nd pump went in with swirl pot

Thought it might be that but the fuel is there and I can hear the pump doesn't change pitch

[ashley]

Are you measuring lambda? Did you inadvertently change your fuel pressure?

[MartinF]

Did you inadvertently change your fuel pressure?

Thinks this is where i would start.

[simpson_eh]

I have not changed fuel pressure but by adding a more powerful pump it's def going to be up, I presume the apexi would sort out the lamda

Still in stock fuel pressure sensor

[MartinF]

I have not changed fuel pressure but by adding a more powerful pump it's def going to be up, I presume the apexi would sort out the lamda

Still in stock fuel pressure sensor

Until you actually measure it you're just guessing.

[simpson_eh]

i thought the standard fpr would control it lol il get another

what is a good one? sard aem etc what are peoples experiences

[MartinF]

Why would you replace something that could be working fine?

You need to be analytical in your approach and not just start swapping things by best guess. Measure the fuel pressure first and then go from there.

[androo007]

Is it the first time / year you've had it out in the cold since mapping?

Just mine is the same (link g4). Minor but highlights need for slight tweak on road map.

[danjama]

Sure it's not the clutch? Does it stop if you dip the clutch?

[androo007]

Sure it's not the clutch? Does it stop if you dip the clutch?

Lol wut? That'd disengage the engine altogether

[Rob66]

I had a similar thing with my na a few years ago bucking and feeling like the car had been lasoed. I changed the Lambda Sensor plugs and leads but made no or very little difference.

I then changed the full exhaust system from a rubbish cheapo to a mongoose and a new cat, the issue then stopped and no issues and running like new again. Could be coincidence of course.