Realy need some help now guys

[Decender]

So, as I posted recently I have had a problem with hesitation and not boosting properly (max I could get was 12-14psi and car is remapped and apparantly should be 1.3bar). After taking it to my local specialist who took readings from logs, did a smoke test and looked at various bits and pieces he diagnosed it to being a faulty MAF and an extremely weak actuator.

So i replaced the MAF which saw a very slight improvement and I have today had someone change the actuator for a brand new Forge one. Just picked the car up and the hesitation is still there and it is still not boosting about 12-14psi.

I just dont know what the hell is wrong with it now. The only error message I have been getting is: 17536/P1128/004382 - Fuel Trim; Bank 1 (Mult): System too lean.

So far ive spent in the region of £400 on bits and labour in the last week and it appears that im know where nearer to sorting it.

Other things that have been ruled out are: plugs, coil packs, dump valve, frp and pipe and breather leaks.

Can anyone shed any light at all on this?

Cheers

Dazz

[@Lee]

just so people reading this know; 14psi = 0.96bar.

[Decender]

Thanks Lee. And thats the max it peaks at. Mostly its around 12psi which i believe is around 0.82bar.

[sammyhale30]

Might you have a boost leak somewhere in the piping?

[BrownBarge]

I got that code when the breather under the inlet manifold was split

Sent from my iPhone 4s

[Decender]

This was my initial thought. Smoke test revealed no leaks.

[dewaryboy]

I got that code when the breather under the inlet manifold was split

Sent from my iPhone 4s

Everytime at work when I've had that code come up its been a burst hose under the inlet manifold,the way they burst they remain closed when no pressure is on them,but once under boost they open up,I would have a feel about at the pipes under the inlet manifold when the engine is running,if one is burst you will hear it sucking air,1.8t engine is notorious for burst pipes under the inlet manifold,if it were me I would rip out all the pipes and sai system and fit an oil catch can,I did this with mine and shark performance mapped out the sai system etc.

[Chris Coates]

System too lean is due to a lambda sensor I would heavily suspect.

If the lambda is good? Suspect dodgy fuel pump/fuel filter blockage.

[BrownBarge]

This was my initial thought. Smoke test revealed no leaks.

On mine theres two hoses under the manifold and to keep things neet they both run threw a rubber sleeve. Mine was split inside the sleeve so was harder to spot. Get some carb cleaner and blast that full area with it with the engine running. If the engine starts to run pants, theres your problem

Sent from my iPhone 4s

[Decender]

Lambda readings have been checked, fuel filters been changed too. All seems boost related as if I accelerate gently and keep the boost at around 8-10psi it doesnt hesitate if I accelerate hard it only boosts to 14psi max and hesitates intimitantly. Im down the garage now and just tried an n75 but that made no difference. Really am starting to pull my hair out now. Will look again for boost leaks.

[missingmyvrs]

You sure its mapped ??

What was your boost actual and boost requested ?

[Decender]

Yeh 100% its mapped. Actual boost is 0.8bar and requested is 1.3bar.

Just been out with the guy from the garage looking at a few more logs etc. At part throttle its fueling sweet as a nut now (it wasnt b4 the MAF was changed). But at wide open throttle its running lean as ****. FPR has been ruled out, fuel filter has been changed, injectors are ok. So its has been suggested that my fuel pump is fubared. Off to pick one up now and will fit this evening.

[Decender]

Well, new fuel pump in and hey presto no more hesitation and car pulls very well all the way through the rev range.

It took a while to find and the other things ive replaced did need replacing so at least no money was wasted I guess. Just glad its sorted

[Chris Coates]

Well, new fuel pump in and hey presto no more hesitation and car pulls very well all the way through the rev range.

It took a while to find and the other things ive replaced did need replacing so at least no money was wasted I guess. Just glad its sorted

I'll refer you to my earlier post - What do I get for winning? Lol