so i had a cel, the ECU Code was # P0302.
which was cylinder 2 misfire, it turned out to be a bad coil, they cleaned my spark plugs and replaced a coil, now check engine light is gone. my mechanic did a compression test while doing that and they are all good, all the cylinders are at about 150psi. however, my mechanic told me cylinder 5 is running extra lean. my car has around 8k miles since my new stage 1 motor from dynosty and is completely broken in, all my pistons are black exept cylidner 5 is pretty clean. he said that cylinder is running lean. i am running osirius and my tuner said you cant jus give that cylinder more fuel. so something must be wrong with my fuel system? he says i should replace my injectors. I am running 600cc DW injectors right now, is that what i should do at this point? what injectors should i get? i am only running the stock wastegate boost rite now on my greddy 18g kit, i dont have my boost gauge hooked up yet so im not sure how much psi im hitting. i havent gotten a boost controller yet to turn up the boost but i planed to after i got a fuel return. so now im gonna do it all at once. my goal for my car is 550 whp. should i get bigger injectors than 600cc so i dont max them out? what size injectors can the osirius handle while still idling good.. any suggestions?? do you think its the fuel injectors causing that problem? thankss

 

You can adjust individual cylinder injector trim with Osirus. You can get your injectors flow tested by DW if you would like to rule that out as a possible cause.

 

you could try swaping that injector to a different cylinder. that way you'll know its an injector problem for certain. id swap it to the other bank.

I cant speak from experience with osiris but if you plan on making 550 whp, you'll most likely need/want larger injectors anyways. I had a problem with my last set of dw 600's just fyi.

 

Cyl's 5/6 are the leanest on a VQ by design. Your tuner is a tard if he said osiris can't do cylinder trim, so you might wanna find another tuner to add few % extra to the rear cylinders.

 

How'd the mechanic know it was running lean? Also are you sure that cyl 5 was firing? post up pics of the spark plugs if you can... might help get some advise. I've seen instances where there was a "clean" piston because the cylinder was dead and just getting washed with the gas.. idk have you talked to the guy that tuned it?

 

if its just only cylinder number 5 , i say flow test the injector...

 

the tuner is good he tuned my car, and was one of the few shops uprev invited down to theyre shop to train to tune GTR's with their software. i think you may have missunderstood him or presented the question differently. he's kind of critical when trying to verbally trouble shoot at times xD.

sounds like an injector issue to me. or if the coil has been bad all this time wouldnt that cause it to have not been firing?

 

I'll bet you it's not a bad injector. I had a similar issue where #4 plug looked lean but an injector test was perfect. I assume he's reading the plugs... which is in effect reading idle trims, not cruize/power trims which may be normal.

 

i dont think hes had it back to the tuner, his mechanic and tuner are two separate people