Help! Engine running way too lean...

[A31_Cefiro]

Hi Forum goers!

I'm hoping to get some help on an issue I am having with my RB20DET.

When it was on the dyno it was found that the car is running dangerously lean when on boost. The A/F mixtures are not smooth either.

I have recently had the fuel pump changed to a higher flowing unit and the fuel lines, injector rail, injectors have all been cleaned. The people who did the fuel pump said that it was running lean so checked the fuel pressure and found that the fuel pressure was ok. They also said they checked the main sensors and found them to be in working order.

On the dyno I was lucky enough to be able to borrow a chipped ECU (thanks!). This ECU improved the mixtures and smoothed them out but the car was still running very lean.

I'm hoping someone can help give me a few suggestions on what to try or what to change.

Any help appreciated.

Thanks for reading!

Will...

[meggala]

have you had the injecotrs cleaned this could be the cause

cause some times they get clogged up kabab found his were block 60% got them cleaned and all was good

might be $25 each injector

hope this helps

meggala

[Jay95R33]

Did you check the fuel filter when you did all the rest? Might be worth a look. Check the vacume/boost pipe going to the fuel reg, if it's blocked the fuel reg won't increase preasure while on boost.

Ummm..... You've checked everything else that I can think of.

Good luck

J

[Mick Trainer]

Check your Air Flow Meters if you have them, especially if you have pod filters. The oil from the pods can bake onto the Air Flow Meters which makes the car lean right out. Take the Air Flow Meter off and hit it with some Carby Cleaner then some contact cleaners. Refit and test again. It worked for me.

Mick.

[A31_Cefiro]

The injectors have been cleaned (that's what I was told and have no reason to believe otherwise...)

Another AF meter was fitted and whilst this gave a slightly better mixture the car was still running lean so I'm guessing it's not the AF but a clean never hurt anything.

I haven't checked the pipe of the fuel reg. Can youpoint me in the right direction to this pipe?

Thanks for all the help at least things checked have been on the right track.

[Guest Nismo_Freak]

Why not replace the fuel pressure regulator with an adjustable unit?

[A31_Cefiro]

Thanks. I'll investigate that too.