boost problem

[PashaK]

i have the following mods:

fmic, turbosmart dual stage boost controller, apexi s-afc 2, k and n pod filter.

before i got the safc2 installed i tried boosting it too 12-13 psi and i was getting this hiccup in the engine when i put my foot to the floor, and i thought it would have to be the a/f ratios, so i decided to get the safc 2 as the power fc was way out of my budget, for $900 i got the safc 2, had it installed and dynoed.

as it was being dynoed on high boost of just under 13 psi it was doing that hiccup thing again, and eventually the guy must have tuned them out cos it wasnt doing it anymore. so i was happy. took the car home and for a few days it was fine, but then it started doing the hiccup thing again, not as often as before but still there and very embarassing when wanting to drag sumone, the whole car would shudder for a second or 2, and keep going, it would literally jerk.

does anyone have any idea what this could be and how to fix it???

sumone said that the boost level was too high and was blowing out the spark in the plugs, so i bought new ones, ngk platinums and regapped them to 0.8 mm, but no improvement, the only way to avoid it is by using a maximum of 75% throttle.

any help would be appreciated...

[GTS-t VSPEC]

Are you sure it's not just hitting the boost cut?

See'ya:burnout:

[Lozza150]

Fuel pump.... maybe not pushing enough juice....

the mapping might be adjusting the mixture's too lean....

just a guess.....

Loz

[2fardown]

Try turning your boost down a fraction.

[predator]

Sounds similar to what mine is doing.. stuttering at above 70% or so throttle, and worse on boost. Get it back on the dyno and see whether they can sort it out.

[PashaK]

thanx for the replies.

the safc 2 takes care of the boost cut, could be fuel pump,

i did turn my boost down a bit, but no help, if i turn it down anymore there wont be any point boosting it

i think the best bet is to get it redynoed but i thought there might be a simpler solution

[TTT]

if this hiccup is around 5000rpm, then it is most likely the same spark problem that all the R33 owners get after boosting their cars.

Have a search in here for "misfire" or "5000rpm" and you'll see other peoples replies.

I think they were saying to gat the plugs to 0.7 (I think)

good luck.

[PashaK]

thanx, i'll check it out

[PashaK]

does the safc 2 remove boost cut/fuel cut???

cos this mite b the prob

[GTS-t VSPEC]

I wouldn't think so. I think the AVC-R removes the boost cut.

See'ya:burnout:

[HoeTrain]

I'd say spark plugs. If the gap is too big the turbo blows the spark out. I bought a six pack of NGK Iridiums and gaped them down to .8mm. Worked a treat.

[PashaK]

thats wat i did already

[rev210]

Change your fuel filter, you should do this regularly anyhow.

The fuel pump issue, will play out like this;

* try getting up to 5000rpm in 1st using light throttle, then at 5000rpm cruise put your foot flat to the floor. If the same issue occurs straight away it's probably not your fuel pump. If it allows you to gun it through first and then starts doing its thing in 2nd or 3rd then the fuel pump might be at fault.

The spark plugs maybe too hot for the load. Try a range or two colder. Buy cheap copper ones.

Check your base timing.

[PashaK]

ive just changed the fuel filter so its not that, it was doing it before and after the change.

i dont think it happens in 1st at all, but in 2nd and 3rd it does only when i put my foot to the floor on high boost.

i think the heat range for my plugs are a 6, could b 7, cant remember

[MRK25T]

My car is doing the exact same thing, I got new spark plugs put in today gapped .8mm. Its been on the dyno yesturday and today and turning the boost down from 1bar isn't helping. I have a standard ECU which will be replaced by a powerFC as soon as I get around to ordering one.

Yesturday I only managed 175.1hp on the dyno.

Tommorow I might have another go.

Mark

[PashaK]

i was told 1 bar of boost is too high for the stock turbo, im running a max of 0.85 bar

[Xeron]

To check the heat range of ur plugs pull one out. If it looks burnt, corroded etc, go one level colder, but i high doubt its that. Just gap to either .7 or .6mm and it could fix the problem.

[MRK25T]

pashak: i've got a high flowed turbo so it isn't really stock, it can handle 1bar+

[rev210]

If it happens when you hit 2nd or 3rd from a standing start test and doesn't act up at all through 1st gear then the fuel pump is perhaps at fault.

When I say standing start or rolling start run at 5000rpm I mean going from 1st through all the gears to 4th as if racing. You might only get to 2nd when it occurs. If it occurs in the later gears and not the 1st fueling is the issue.

It could be ecu 'fuel cut' also.

[PashaK]

i was told the safc 2 removed fuel cut?

becos i had a fuel cut defender in there before i got the safc 2 and when i got the safc 2 installed he said i dont need the fuel cut defender anymor

i'll take the car for a thrash and see if it does it in 1st or not...

i was actually driving it pretty hard yesterday on high boost and it didnt do it once, seems to do it when ever it feels like it