Hi guys...

A friend of mine has been having misfiring of his spark plugs...

He has a 2.3L block, ported & polished the top, 270 cams, walbro & a paxton external fuel pump, after-market intercooler, fuel reg, bigger fuel rail, aquamist, GT35r .82 & AEM on his evo.

He is boosting at 2bar....

But after a couple of pulls on the road, the mis-firing came in. ..the boost just flutters & the engine stutters....

He put in a HKS twin power & changes his plugs to a set of NGK which is a range colder than stock. Still happen after a couple of runs.

Than he decided to change to NGK racing which is number 9. Regapped it slightly. Same cycle repeats...

Wat could this be?

Thanks...

 

What are the plugs gapped @? I had the misfire problem and i took the gap down to .20 and problem solved. Im on stock turbo though running like 21pSI.

 

will your gapping cause the spark to be less bright since u gapped it til so low?

i tink he gapped it to 0.3

 

Because your saying its occurring after a few runs, it could be the coils overheating.. Although I haven't experienced what your describing, you might want to swap on a new set of coils and see if that helps..

 

That is a idea, i will let him know.....thanks MalibuJack...your HKS DLI write-up on your ride is helpful.. ;>

Coil overheats when they are old ixit?

 

gap should be around, .24-.28..

 

Just check timing light.

 

may i know wat is a timing light?

 

Malibu has a good point. Also have him pickup a set of NGK BPR8ES (colder plug) and some BPR7ES and gapped them down to .25 jsut to see if you have any issues. If you don't then open up the gap little by little.

 

It sounds like he is either fouling the plugs or the car is leaning out.
Everytime he puts plugs in it runs fine until he does a couple pulls then the plugs crap out.

What do the plugs look like? Black, Brown, white?

 

Both of us took out the plugs, & it is sorta of blackish brown....

What are the data from AEM EMS that u guys need so that u can advise wat's wrong with it? Let me know & i get him to pass it to me.

 

i have the same set up with utec and stock ignition and have the same problem, i just had to turn the boost down to like 22-23 PSI and it runs fine. Im waiting for my AMS ignition to get back.

 

But tot for the GT35r to kick in, u have to boost around 28psi & above?

With your 22-23psi boost, wat r the figures u r hitting? wat rpm than u see your powerband coming in?

I am so worried that i will face the same set of problems too..if not i will have to opt for the 3071r kit instead of the GT35r...