Miss Fire at 5000 rpm

[chiefpulsar]

I've just fitted a fmic to my pulsar and the boost has increased without the use of my greddy boost controler to about 1.2-1.3 bar, the car starts runs and goes fine but at about 5500 rpm the car starts misfiring, not bad but you can certainly fell it.

When i had my tmic i had the same problem at the same rpm so i changed my spark plugs to HKS superfire (s40i) this solved the problem.

This time i changed my spark plug to the NGK iridiums XI, the chap who i bought them off asked me about my bhp (which is about 310-320) but i'm still getting a misfire.

The modifications i'v got on the car is a follows=

induction kit
turbo back exhaust
uprated fuel pump
front mount intercooler
organic clutch
apexi fuel controller
greddy profec B boost controller
NGK iridiums

Can anyone offer any help on this please if so i would be grateful

thankyou

 

[m34ts_pulsar]

lol funny you should say that.. last nite mine did the same!! i left from my house to go to my girl friends and its only about 2mins away in the car, there was nobody on the long straight hill so i put my foot down in 3rd gear to 4th at around 5k revs it started mis fireing... mine was due to not letting my car warm up enough before boosting.

5mins later of normal driving it was pulling like a train again :-D

( ive just fitted the straight thru ss mongoose exhaust with the 5" tail) im sure this makes a differance in doing the odd popping at high revs but im unsure.

 

[chiefpulsar]

the thing is my car is warmed up everytime before i use it after about 6000 rpm it still misfires but not quite as bad, i'm thinking its down to plugs and leads, i've read that everyone likes the magnacor leads but where do i get them from?

 

[Braveheart]

I had a similar problem.
I picked up a GTIR last month and felt it was running a bit funky. It seemed to pick up ok at low revs but stuttered and hesitated badly between 4.5 - 5k rpm. When I layed off the gas the damned thing wanted to go. Not good when you are entering a corner looking for engine breaking. It was also idling high (1100rpm) and just felt a bit unwell.
The car it's self is bulk standard except for a mongoose exhaust (without cat) and sump guard but with a poor service history (jap 18k service). I bought it off a farmer who had owned it for 4 years and done 2k miles in that time. It has 60k on the clock, it was imported in 2002.
Anyway, given the service history and poor performance, I booked it in for the full boona.
Falkland performace changed all the fluids, plugs, point, air filter (now K&N) front disks and pads and rear pads. (disks and pads were well shot.... it was grinding along)
I was full of hope but the car was still running poorly.
It turned out to be the knock sensor (error code 34) This sensor they explained was there to pick up pinking etc and when triggered would retard the ignition timming by 6deg. It's meant to reset it's self but did not and I thing I will source a new sensor.
They reset the ECU and the error was gone. The car is now running fine. Much smoother, pulls all the way through the rev band and thankfully enters engine breaking now when I gas off. I did refrain from taking it out on the track at knock hill last sunday however as I have a sneaky suspition the problem would return plus I did not want to buy another set of brake pads so soon.

Hope this information helps and I may post it in a couple of other places on this web site.

Lang may your lumb reek... all the best Braveheat (Scott)

 

[chiefpulsar]

well i just came back from poole with my girlfriend and along the duel carriage way i applied about 3/4 of throttle and she accelerated good as gold all through the rev range without any problems.

However if you put ur foot hard down on the throttle she will still missfire and the hesitate at 5500 rpm, but after that she runs fine........

 

[Mr GTiR]

i've read that everyone likes the magnacor leads but where do i get them from?

Don't waste your money on them, get standard Nissan leads which are the best IMO.

Take your dizzy cap off and check all contacts are ok and not worn. While your at it, check the rotor arm and plugs. If the plugs look ok then give them a clean before refitting.

 

[the chief]

check to make shore theres no water in the spark plug hole

 

[chiefpulsar]

there is no water in the spark plug hole as i've taken them all out and checked, i've also bought the nissan leads as everyone says there good for 400 bhp (which i'm no where near running) but the problem still persists, but i havent checked the dizzy or arm or points.

wat about ignition timing?