on going missfire issue *help*

[huu-raa]

right ever since i have had this GTiR ive had a missfire problem the missfire can be heard at idle and is promiant @ 1400rpm you can hear it more if you lift the revs slightly.

i have changed the plugd and gapped them
i have changed the leads for new ones
i have changed the dizzy cap for a new one
i have changed the rotor arm for a new one
i have fitted a new walbro fuel pump
i have fitted a new fuel filter

might not seem like a bad missfire as its at idle and 14000rpm but when driving its very noticable like its struggling . ive also replace the DET sensor and fault code 34 was up i have since cleared the code and its showing code 55 (all clear)

im really stuck on how to cure this to be honest so any help would be great, i am going to re earth my MAF but doubt if its goona solve this issue as this is a nightmare to me now lol

 

[Davie Houston]

Has the timing been messed about with? maybe timing is a tooth out matey?

 

[huu-raa]

ive never messed with it but hte DET sensor was away when i bought it so maybe timming was advanced to suit???

 

[Davie Houston]

Maybe worth pulling the rocker cover off matey and check the timing is all spot on, and the timing marks on the pully`s are spot on.
As you have changed everything else, and still ahve the same problem.
Have you done a compression check? as this will show if theirs any compression differences between the cylinders, should roughly get about 150psi across all 4.

 

[huu-raa]

will get to a compression test but didnt wana think the worst as its just a missfire lol

any other things to try?

also any advice on checking the timming? how to ect? just marks ok pullys

 

[donpulsar]

Could it be a lack of fuel ? May be worth getting your injectors cleaned and tested cos if one's blocked/stuck/dribbling etc then that could give the same problems ?

 

[huu-raa]

whats the best injector cleaner to use?

 

[GTIR-LOZ]

its best to remove them then send them to a proper place that can clean them, that fuel additive stuff takes a while to work (if it works atall)