Misfiring RB25det

[Black R-33 4Dr]

Gday guys

I was wonderig if anyone out there had]s experienced the problems i am having with my misfiring engine. Currently the engine accelerates up to 3000-3500 ok. The problems then start. If I try to accelerate using full throttle the engie misfires and pops out the exhaust. It feels really flat and hesitant. Once the engine finally reaches approx 5500-5800 it takes off like a rocket all the way to the limiter. I am having thoughts on the coils and perhaps exhaust cam timing.

Mods are:

Hi flow turbo, 3" inch mandrel turbo back, plug gap 0.7, boost set at minimal 12psi,

checked A/F ratios , are fine,

If anyone has any thoughts could you please assist before i need to start spending big bucks, Knowledge in Tassie is minimal as the low volume of these vehicles.

Cheers

Nick

[rb25]

hey nick, i'm pretty sure its your plugs. Have a bit of a search, heaps of info to enlighten yourself with.

-rb25

[OMRAN]

i have the same problem .. i posted 2threads ... (IS IT THE COILS) AND (SICK..!) SEARCH for those threads .. and read .. u may have some ideas ..

[rb25]

ok, i overlooked the 0.7 plug gap. sounds like coils. i have just been through this tonight with my car, 0.7 gap and still a misfire - coil packs....

-rb25

[EFI_fixer]

Hi Nick,

Am interested to know what kind of boost you are running. Is the amount of boost dropping off at high rpm? I ask this because it is harder for a spark to jump the same gap in a higher density atmosphere. Reducing the gap or cutting back boost may prevent the car misfiring, but will put a dent in your performance as well.

I'd be inclined to try out a set of Bosch Super 4 spark plugs if you can get a set to suit, as they do provide superior ignition. Otherwise you may need to get a set of coils or an ignition module with a stronger output depending on which is holding it back.