Fuel Pump woes, what to do?

[gogg]

Ok, I'm like %90 sure my car is running on the rich side (worsened by summer weather) because I have a walbro fuel pump ... on my stock KA motor. I haven't gotten my hands on a fuel pressure gauge but for this thread lets just say thats the reason (I already did the thing where you squeeze the return line to see if it revs, and yea it did). So anyway I was wondering what would be my best bet, either get an aftermarket adjustable FPR or just go back to the stock pump (which I would have to buy). I'd to like to have adjustability, for the track and weather, but if my car runs fine with a stock pump then I guess its not all that important. It's more of a question can I find a reliable adjustable (non rising rate; 200KpA or less min rate) regulator for under $120 or so. Thanks.

[gogg]

Bump, no help? NISTECH doesnt think its the regulator.....

[Silvia007]

Well, how do you know you're running rich? If you think about it, getting a 255lph fuel pump will not increase pressure, it can flow more fuel when it's needed and flow more at higher pressures. But what controls the pressure? The FPR, so what does that tell you, your FPR may be defective or the vac line to the FPR is either cracked and haveing vac leak or your FPR is busted.

[jared]

IF I WERE YOU I WOULD ALSO SEE IF YOU HAVE ANY SENSOR PROBLEMS, A BAD O2 SENSOR MAF, YOU MIGHT EVEN WANT TO TEST YOUR FUEL PRESSURE TO SEE IT YOU INJECTORS ARE LEAKING CUZ THAT COULD CAUSE YOU TO RUN RICH, MAKE YOURE RINGS STICK WITH CARBON BUILD UP

[SeVa-S13]

The Walbro is indeed a higher pressure, not just higher flow pump. Spend the $100 on a regular Nismo FPR, tune it to 43psi with the vacuum line off I think. Once the vacuum line is reattached it should drop to 35psi.

[:: orion ::]

I'd to like to have adjustability, for the track and weather...

The beauty of the MAF based engine management system is that you DO NOT need to adjust anything for weather.

Your MAF reads the MASS of air entering the motor...so if the air is hotter, and less dense, then less mass is read by the MAF and less fuel is injected. Very simple, and VERY effective.

...

And a Walbro won't typically overun your stock FPR...even though it can flow more volume and higher pressure, the extra fuel is returned to the tank...and the pressure should not increase unless you FPR is bad.

FYI...

If you're running rich, Id look at the coolant temp sensor and TPS first.

- Brian

[gogg]

The Walbro is indeed a higher pressure, not just higher flow pump. Spend the $100 on a regular Nismo FPR, tune it to 43psi with the vacuum line off I think. Once the vacuum line is reattached it should drop to 35psi.

You have a walbro on a stock KA?

[Silvia007]

The Walbro is indeed a higher pressure, not just higher flow pump. Spend the $100 on a regular Nismo FPR, tune it to 43psi with the vacuum line off I think. Once the vacuum line is reattached it should drop to 35psi.

In this case, I was refering to his stock FPR setup, the pressure wouldn't be much if any more then if he was to still have his stock pump.

Before I got my SR, I was running a Walbro 255lph with my stock KA engine and it ran fine.

[SeVa-S13]

You have a walbro on a stock KA?

No, but the pressure is universal for all Nissans. With just the Walbro and no FPR on my RB I ran rich at idle and a little lean under higher demands. $100 is cheap insurance.