[yogi bear]

I'm a bit confused. I've just finished hard wiring a 044 in the tank.

Cranked it over, fired it up. And the damn thing is so rich it looks like a john dere tractor!
And is struggling to run smoothly.

The car was a r34 rb25de. But it's had a rb26 conversion.
When I got it, it was still on the stock non turbo pump. So I've thrown a bosch in the tank and now I have this problem.

Have you encountered this before? Has anyone ever had to change faulty fpr?

 

[Fuzzy]

You need a adjustable FPR. The OEM FPR can`t drop the Pressure

 

[yogi bear]

But the pressure *should stay the same. It should just return more fuel to the tank

 

[Fuzzy]

Stock one are to small for big fuelpumps

 

[Barros777]

Fuzzy is right, the new pump is "stronger" that the old one. So you need a remap.

 

[geoffree]

Surely posters aren't suggesting an 044 is a problem for an Rb26?

 

[yogi bear]

My thoughts exactly!
Maybe I've touched something else and that has caused the issue

 

[geoffree]

May have to remove the engine bay pulse damper from the return line.
Also check your Bosch install to ensure there's no squashed return hose or something simple.

 

[Rain]

Fuzzy is right, the new pump is "stronger" that the old one. So you need a remap.

Reeeeealllyy?

The pumps only job is to send fuel to the rails/fuel system. What ever isnt used gets sent back to the tank via the return.

A tune will not help him.

by process of elimination : Check the obvious as people have said, You might be causing the FPR issues it wouldn't hurt to check it also.

Edit: Clarification, why did you go for that pump ?

 

[jabran200]

The fuel pump will not affect the fueling on its own i.e if your old pump could supply enough fuel at max rpm and boost then the new larger pump woudn't make a difference especially at idle.

The fuel pressure regulator is the only thing that will affect fueling so if for example your old pump was weak and someone had adjusted the fpr to correct the afrs than it could be richer now compared to before.

if that isn't the case and you have a stock fpr than you have faulty fuel pressure regultor or something else is wrong.

I am running an 044 on the stock regulator at 600+bhp without issues.

 

[Dan ep3 turbo]

Fuel pump will not effect afr it's just a supply like rain says. I have 2 044 pumping to standard rail and reg works perfectlt

 

[yogi bear]

Looks like I've sorted this now guys. Not entirely sure how. But Thanks for the input.