Fuel pressure questions

[mabru]

My RB25DET has an adjustable FPR on it and a walbro fuel pump. I've noticed a loss of power throughout the rev range lately. I checked all the sensors, checked base timing, put brand new iridiums in it, and I'm running splitfire coilpacks. I checked the fuel pressure at idle with and without vacuum and they seem ok.

Sometimes while I'm watching the fuel pressure gauge I'll see it dip a few PSI slowly but surely and occasionally I have to readjust the FPR to compensate. I've done a few of these adjustments in the last few days. Basically what I'm wondering is if my fuel pump is on it's way out?

-Matt

[danieltangtc]

Sure looks like it man...really sound like a fuel pump problem to me. The walbro pumps also do not function at very high pressure unlike the bosch 040/044 and GTR pumps. Go get yourself a new pump!!!

[mabru]

I've got a spare HKS pump, guess it's good I still have it

[paulr33]

i recall seeing a few threads covering the walbro pressure levels and how much they pump. on skyline wiring it only gets 12volts, and its pressure levels and pump per/hour levels etc are based on 15volts (such as in supra im pretty sure). do a search on walbro 15volts and you should find it, may be causing your problem

[mabru]

This pump was fine for quite a while, it's only recently that it started dropping pressure, and it's intermittant. I'll swap them out and see if my problems fade.

[R31Nismoid]

Get rid of the walbro.

They are a lard of junk once you push on them. Ok if you running it as a lifter pump for a surge tank, with a big bosch after that... then you wont notice the problem like i will be doing.

I was far from happy with my walbro, so it was more cost efffective to do a surge tank/bosch/walbro as a lifter setup than throw away some $$$

As for an FPR, you shouldnt really be using one anyway. There is no need

[Abo Bob]

Why do you say there is no need?

I installed a Walbro and it ran rediculously rich because the fuel pressure was too high. I'm looking for a regulator to bring the pressure down.

[R31Nismoid]

for the answer to your Q. see your own thread