misfire diagnosis help

[thelegend]

Hello bit of an introduction

I am a bit of a newbie in the world of the GTIR and have recently bought myself an import on a L plate that someone was selling for a very sensible price due to an unknown misfire, being quite handy around engines I decided to take it on as the rest of the car was in very good condition.

I have browsed around the common faults section and so for between me and the guy i bought it off tried the following

new plugs
new leads
new dizzy cap
re-earth the MAF
rewire and earth fuel pump
new fuel filter

Still no joy around 3.5k as the boost kicks in it hesitates then misfires all the way to 7k although sometimes better than others. One thing i have noticed is on the pipe that connects to the turbo (3 bolt flange) one of the bolts has been sheared, this looks as if it could be leaking do you think this could cause the misfire problems mentioned?

If not please throw some more ideas at me so i can get this sorted, the engine isn't throwing any error codes so its probably something stupid.

cheers

paul

 

[Rishi]

Coil

 

[Rishi]

Injector Resistor Pack..

 

[gtirneil]

Mine was doing this for 6 months before i spotted the problem, on mine it was a little grey clip that had come undone so would misfire when boosting, or going over bumps, i have no idea what its called tho

Its just infront or the factory oil catch tank on mine

 

[powerfreack]

it could be down to the pipe with the 3 nuts in as that will be the intecooler and that would cause misfire if its not tightend up propley

olso check your manifold

and what plugs did you fit and what is the gap on them

 

[daz]

i sheared a bolt off the compressor outlet (ie 3 bolt flange) ages ago on one of my old turbos and it made no difference at all and no mis fire. i like rishi would point the finger at the coil inj resistor pack or too big a spark plug gap. ie when it comes on boost it blows the spark out

 

[thelegend]

thanks for the replies so far

the plugs are some grade 7 NGK from nissan can't remember the exact code but could find it out if need be they are gapped to 0.8mm running standard boost this should not be an issue.

I'll fix the sheared bolt on the intercooler/turbo pipe see if that helps then replace the coil, maybe its just getting old

any suggestions on a coil? stick with stock or is there something better out there?


cheers

paul.

 

[daz]

if running standard boost and ignition then stick with stock nissan they are good enough for what you need

 

[Fast Guy]

Try a fault code check incase something turns up.
It could be a boost leak from somewhere tho. Check for loose or split boost hoses.

 

[thelegend]

Try a fault code check incase something turns up.
It could be a boost leak from somewhere tho. Check for loose or split boost hoses.

I am pretty sure the pipe i mentioned earlier is leaking under boost, going to fix that first see if it helps. Tried a fault code check and shows up nothing

should have made it clear earlier, this car is going to be my run around so i am not looking any further than the following (if i can cure this misfire)

boost upgrade
fuel pump
front mount intercooler
possibly a unichip to keep fuelling in check

so i think a standard coil etc should be up to the job if anyone knows different or knows of a cheaper suitable alternative please let me know


cheers

paul

 

[Fast Guy]

Oops, I missed that bit. I had the factory dump valve hose just come off and the car ran like a pig, so I guess if you're leaking from there then it could have a similar affect. Only one way to find out;-)

 

[thelegend]

Oops, I missed that bit. I had the factory dump valve hose just come off and the car ran like a pig, so I guess if you're leaking from there then it could have a similar affect. Only one way to find out;-)

I know its just gonna be a PITA to do


paul

 

[stevepudney]

Ask around and see if anyone has a spare standard coil they will lend you so you can illiminate that. Try PM'ing Jimmy.

Welcome to the club by the way.

Steve

 

[thelegend]

thanks for all the replies,

i'll have a look around see if i can find someone to borrow a coil off before i go try one

cheers

paul

 

[thelegend]

Thanks to thunder god and his mate (sorry didn't catch your name) the problem has been diagnosed to be a faulty MAF.

just need to find one now so if anyone has one lying around in their garage please let me know


cheers

paul

 

[kirko]

pm sent