vn petrol issues. please help

[NV-VN]

hey guys just after some advice. when i accelerate quick it chokes for a bit then picks up, but if i accelerate slowly it doesnt choke.
ive changed spark plugs. coil pack. fuel filter.

if anyone knows would be great
cheers

[accentstencil]

If by choke you mean it misses, then I would be looking at spark plug leads.

[wortus]

I think you need to check your throttle position sensor and maybe check for a blocked air and/or fuel filter but I'd suggest the TPS as what your describing could be the mixture leaning out as the throttle is opened akin to the accelerator pump on a carby not working properly.

[NV-VN]

oh ok. because if its not missing. it was missing before i put the new coil pack. but when i accelerate quickly it chokes then picks up and a bit of black smoke comes out of the exhaust
please explain

[wortus]

oh ok. because if its not missing. it was missing before i put the new coil pack. but when i accelerate quickly it chokes then picks up and a bit of black smoke comes out of the exhaust
please explain

Don't really understand you there. Look up Lean Misfire. You have checked all your spark plug leads resistance already?

[NV-VN]

sorry made a spelling error. it does miss. it splutters when accelerating then picks up.. i went to check the resistance but ive got the new fluke metre and it only goes up to 1k ohms bloody hell

[xCalliba]

injectors and fuel rail? though i guess if it was them it would be choking under any throttle load...

[wortus]

sorry made a spelling error. it does miss. it splutters when accelerating then picks up.. i went to check the resistance but ive got the new fluke metre and it only goes up to 1k ohms bloody hell

No worries. I'd be checking the throttle position sensor and its wires. Disconnect it and try reving the engine and see if it's worse.
It's just a variable resistor so you need to check that it is within range and linear I'd guess.

[mistergTRx]

have you cleaned the I.A.C valve?
i had a similar issue on my bluebird (it had the ca18) and i replaced plugs, leads coil pack etc) and no joy, so cleaned the I.A.C and was much happier after that

[NV-VN]

ok thanks wartus il do that. sorry for being noob. but not sure on where abouts it is. if you could explain as ive never looked for one before
and mistergTRx cheers for that however what and where is the IAC valve?

cheers fellas

[mistergTRx]

ok thanks wartus il do that. sorry for being noob. but not sure on where abouts it is. if you could explain as ive never looked for one before
and mistergTRx cheers for that however what and where is the IAC valve?

cheers fellas

VP Commodore Idle Prolems

theres a picture of one and where it is on this thread

[wortus]

ok thanks wartus il do that. sorry for being noob. but not sure on where abouts it is. if you could explain as ive never looked for one before
and mistergTRx cheers for that however what and where is the IAC valve?

cheers fellas

It's located on the throttle body. It is a variablke resistor and it's wiper arm moves with the throttle hence sending back a voltage output to the ECU which is read as throttle position. It needs to be within a certain resistance range and the rate of change shoudl probably be linear.