Before i go into issues heres a little run down on the ute so people understand,
2003 Mazda Bravo G6 12valve
Turbosmart 1200 fpr
turbosmart 40mm wastegate
28/76 turbo - 0.76 rear housing
runs 8psi
walbro 460 fuel pump
GFB g-force3 with wideband o2
stock ecu
engine is stock minus a bit of head work

so that being said ive noticed its breathing heavily out the catch can and has a miss once it gets up on boost just past 5psi and uses alot of fuel, im trying to get an understanding on these engines as ive only bought the ute not built it,
its getting a fair amount of blowby im guessing possibly a ring?
the fuel consumption is real bad ( fpr is at 55 pound )
other then these two issues the ute drives fine just wondering if anyones had anything similair,
is there something that could be done to the factory ecu maybe to help the fuel issue?
new rings?

any information would be greatly appreciated, im new to owning a b2600 ive always owned holden rodeos (isuzi) and mitsubishi tritons (mighty max)

 

 

Whats your A/F ratio cruising, and what is it under boost?

 

The AFR is sitting on 14.3 to 14.5 idle then on 5 pound it goes to 16 on 8 pound its highest it spikes form 16 to 17,
im guessing its maybe run out of injectors i could be wrong

 

When it goes into boost your A/F ratio should go down to between 11 and 12. Higher than 12 and you asking for trouble.

You are way too lean under boost. Fix that immediately or you will kill that engine very quickly. When it goes lean under boost, cylinder pressure goes way up as does combustion temp. You can melt pistons and blow that thing into pieces like a grenade.

If you don’t know how to tune it, get it to someone who does. Hopefully there has not already been damage done to the engine. Don’t put it into boost until this is fixed.

 

Thanks mate appreciate the comment, all the work is getting done at a highly recommended workshop just wanted to clarify some issues before i take it there.

 

Sounds good.

Generally speaking, an engine under boost is having additional air being forced into it. Any boosted setup needs components that reference boost, and or reference the amount of air being ingested. The system then adds additional fuel match the additional air going into the combustion chamber.

When you get it fixed, I strongly recommend you pay attention to the wideband when pushing into boost. If there’s one gauge you watch, it needs to be that one. If it goes lean, back off the throttle or else, KABOOM!!!