Rb25 Misfire Pleasssse Help

[honan]

Quick info on the back ground

Have just installed greddy style plenum onto r33, has hiflowed injectors, splitfire coils etc

Took it too a mech to get it running a touch smoother and maybe fix the misfire. The car is idling better etc but the misfire is still there.

He has replaced the plugs and all 6 ARE firing

All injectors are squirting but number 6 he was suspect of.

He has checked all vac lines, cooler pipes etc..

The car is acting like it is a vac leak and before the manifold the car was tuned and running fine at 260rwkw.

Now is is possible that the manifold has not quite sealed right back at the last cylinder

OR

the injector o-ring where the injector presses against in the rail.

The mech/tuner is good at most things..but nistune is something he does not do.

Any other ideas...

I'm dying to be back on the road...please help

Thanks guys

[GTSBoy]

These are famous for not having straight flanges.....

[honan]

Sorry forgot to mention

Chris Milton engineering machined the face for me 3 days before it was fitted!

[DVS JEZ]

Is it a constant missfire?

Check the spark plugs. They can tell u alot

[honan]

Yeah plugs have been checked...the car is running a rich as I need the afm settings changed again.

It's a constant miss on the 6th cylinder only and everything points to a vac leak

It struggles to drive around town but feed it some revs and it drives alot better.

[KiwiRS4T]

Also look for pinholes in the casting of the Greddy copy - some are fine some are not.

[honan]

Had the plenum pressure tested also

Now today I started the car...white smoke which is generally oil, as last night was its first drive, I'm assuming built up oil in the intercooler from the rocker vent has found its way back to the plenum?

So I though stuff it, pulled out cyl6 injector...o-ring has had it-I would say this is flooding and not igniting as its to wet, causing misfire and rich conditions.

Checked another injector. This one was not as bad but is not at all good.

So I pulled the pulled the plugs, cyl 4 and 6...both wet with fuel but have fired since being replaced yesterday...have splitfire coil packs and theyre fine.

So I'm selling some parts on here I don't need, wondering whether I buy new o-rings OR when the stuff sells buy new JECS 650cc injectors rather than my hi flowed factory items?

Ahhhhh joys

Also no water in oil and vice versa-compression is fine