I have just recently installed a bosch 044 external and now Im seeing 60psi on my pressure regulator and when I try to adjust to make it lower it dosent do jack.. was previously on 44psi base pressure.

I have not upgraded the return line to the tank as I was told it should b ok. Could there be a back pressure issue?

 

are you running the stock Fuel pressure reg?
Sounds like it can't flow enough, and/or the pump is flowing too much at idle. (i'm assuming you're talking about idle).
But then people run double pumpers full time and dont have overrun problems...

Where abouts did you mount the pump? with a separate surge tank? i've just picked up my Bosch 044 and i'm going to install it once i get my run-in tune done.

 

hey mike

I have a turbosmart FPR800 and yes this is at Idle. It is mounted with a surge tank. and its mounted next to the fuel tank under the car. I run a walbro as a pick up and the bosch as the feed. the car is going to get the final tune on thursday at speedtech... and I need this sorted before then.

 

can you try another regulator?
A stock one?
Another one with a fuel pressure gauge?

You might have to run a relayed circuit with a 9v/12v switched setup at a certain boost.
I'm sure Andre and the boys could sort it out, but it'll cost you!

 

considering this regulator is only a couple of months old I doubt it would be that?? and as for costing, thats the reason I posted because I dont want to spend a small fortune..

 

I apologize, I wasnt payin much attention to the post, I was under the presumption you were referring to an FPR not pump

 

well it is part of the equation

 

I just got through putting a newer fuel system on a VW corrado. The previous owner decided to make it a returnless system, w/o having the chip tuned for the higher fuel pressure. I was able to correct this and got it running fine it was just a PITA(pain in the ***) just in case

 

By the way, have you upgraded the fuel feed and return lines? A larger inside diameter will drop the pressure in the fuel rail as well as the lines and still give you the volume of fuel you need for higher power applications

 

Fuel feed line size shouldn't matter if he's over pressurising at idle.
It's either the Fuel Pressure regulator or the Return line, or he's just flowing too much fuel at low load (bosch 044 flows less than double pumper walbro).

Are you 100% sure the aftermarket Fuel Pressure reg flows more than the stock regulator? You might be surprised.

 

The problem shouldn't be the regulator. The problem is almost certainly the plastic siphon tube in the return line (in the tank), whose orifice is too small to handle the increased volume at idle. It creates a backlog of pressure that is manifested as excessive rail pressure, which cannot be lowered via the FPR. This is definitely an issue when dual pumps are run in parallel, and apparently when they are run in series as well. Obviously, with the bottleneck further down the line, FPR adjustments cannot fix the issue.

So long as you have a 9/64" (3.5mm) drill bit available, you should be able to resolve this easily:

https://www.evolutionm.net/forums/ev...ould-know.html


FYI

 

I had this pressure reg on before the bosch was installed and I was running a single walbro and up'd the pressure to 44psi base. then switched to bosch and BAM 60psi when cold.. I just drove it down to my local shop and checked it again and it was at 70psi on idle (when warm)

they are going to look at the return lines and also check out what TedB suggested so I hope to have it fixed today.

 

any luck with this?

 

yup yup sorry mike.... I took it back to the shop who made and installed the surge tank etc... they re-checked the lines and found that a return line was twisted on the install and had a big kink which blocked the fuel... Once that was fixed the pressure went back to 40psi on idle. Needless to say I was pretty happy. I also got them to take the little plastic return line out and re-drill it as TedB suggested to be sure.

Right now Andre at Speedtech has the car and is attempting to convert it to Speed Density. It'll be his first so it'll be interesting to see what happens...

 

hows the tune and SD conversion going mate?