Hesitation On Acceleration

[r33skyhigh]

hey guys picked up my r33 yesterday and has a mad hesitation not only on boost but even down low, when accelerating it hesitates, then power comes in then hesitates once again.

today i changed the fuel filter finding the filter itself inside the housing was rattling around. it made it slightly better.

the car has a large bosch fuel pump in it and the next stage it to replace that.

if anyone has had anything similar in the past i would like to hear about it.

Thanks, Paul

[CGB_R32]

Im having the same problem in the 32, from the research ive done it could be a) the AFM(s) if so give them a clean, b) the spark plugs, if so grab some new ones c) coilpacks, silicone them up or replace them or d) 02 sensor, this is a bitch to check but ive decided to bite the bullet and get them replaced for peace of mind. Im installing new plugs and coils today, well let you know how it goes. In the mean time theres a sticky'd 02 sensor section or go here http://www.skylinesaustralia.com/forums/Mi...sensor+problems for the other ideas ( he had a 33 gtst aswell)

Edited October 14, 2009 by CGB_R32

[blind_elk]

It's not the f#$%^n O2 sensor - its input is totally disregarded by the ECU during acceleration!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! How many F$%^&*N times does it have to be said!!!!!!!!!!!

[/rant]

Now, I know you've only had the car for 1 day, but what mods does it have? Aftermarket ECU? Atmo BOV? Anything else?

[r33skyhigh]

Now, I know you've only had the car for 1 day, but what mods does it have? Aftermarket ECU? Atmo BOV? Anything else?

thanks for the help,

umm its got forged pistons, cams, big garret turbo, full exhaust with extractors, full motec, front mount, bov, upgraded fuel system, upgraded ignition system, rims, all whiteline suspension + more i cant think of.

[mad082]

It's not the f#$%^n O2 sensor - its input is totally disregarded by the ECU during acceleration!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! How many F$%^&*N times does it have to be said!!!!!!!!!!!

[/rant]

Now, I know you've only had the car for 1 day, but what mods does it have? Aftermarket ECU? Atmo BOV? Anything else?

i'm guessing quite a lot more times yet, LOL

i'd start with the simple things like plugs and work your way from there.

[turael]

i had something similar with my SR 180 when i first bought it. tried everything, ended up being the fuel pump.

what plugs are you running, maybe you need something hotter... had some shitty hestitation when i swapped engines in the 180, swap from plat plugs to copper ones fixed that. worth a shot at $3 each

[CGB_R32]

It's not the f#$%^n O2 sensor - its input is totally disregarded by the ECU during acceleration!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! How many F$%^&*N times does it have to be said!!!!!!!!!!!

[/rant]

Now, I know you've only had the car for 1 day, but what mods does it have? Aftermarket ECU? Atmo BOV? Anything else?

I stand corrected.........................wacked in the new spitfires and plugs and yay no hesitation any more!

[r33skyhigh]

im running iridium plugs, and they look near new. coils are good too not arcing around edges.

im a mechanic so i have run fuel pressure tests to eliminate the fuel system.

i have also quenched the cam sensor and that made no difference

took out plugs and coils today to check them, put it back in and didnt seem as bad, took longer then usual for it to start stuffing up i think i might fill the plugs with a grease to see if that fixes it.

[GTR-N1]

Can you swap the ECU then, with a mate? You know what I mean with your mechanical knowhow.

blind_elk may have nailed it 4 U

[r33skyhigh]

yea the thing is its running full motec and i highly doubt that will shit itself. i have to get a cable for the motec to plug a laptop in and see hte problem,

again this avro will b more diagnosing and ill see how i go, thanks for the help so far guys

[Birds]

I thought oxygen sensors remained in use (closed loop) until wide open throttle, i.e. until the throttle position sensor is maxed out it's still going to be used?

[r33skyhigh]

did abit more work today, tomorrow i am putting my mates r33 coils in my car and seeing how it runs. hopefully better.

gota do a few little things like change belts, service, brake fluid flush ect, and polish it too so its a big weekend for me!

[turael]

I wanna see what happens if you change to a hotter plug

[r33skyhigh]

looks like im doing the coil swap tomorrow spent all day polishing it haha

[PRIMRK]

Coils...just got some new ones today, makes a hell of a diferance...3 of mine where stuffed...all new now...sigh the things you do to get a car ready to sell...

[Dorifta]

if ur prob is as described, $20 its ur afm, it the only componet on the car to cause hesitation on off on, nothing else will do it