fuel pressure help!

G'day from Australia everyone,

I've got a 2005 GGN25R toyota hilux, which is nearly identical to the current tacoma's as far as mechanical components are concerned. The fpr/fuel pump assemblies are the same part number, but the hilux has an inline filter in the engine bay, tacomas do not.


I've been having problems with my fuel system over the past 6 months.

It started hesitating until above 2000rpm in every gear, to counter this I installed a URD fuel pump upgrade kit. Problem gone.

Then, the pump would start making a loud whining noise if the car idled for more than a minute, I thought the pressure must be getting to high at the fuel rail and with the regulator not returning fuel to relieve the pressure, the pump would be working against the pressure in the system.

To counter this I installed an adjustable fuel pressure regulator from the back of the fuel rail. I set it to around 38psi, and the pump stopped making noise.

Since then I have noticed that the fuel consumption is up around 15-20%, and am unsure why.

I am thinking about returning all the components (fuel pump assembly/fpr) to stock, my question is, does anyone know the lph rating for the stock tacoma fuel pumps?

Can anyone advise me on other possible problems/solutions to the fixes I've been making?

Any hep would be greatly appreciated!

 

g'day to u too sir.
so, could the filter be clogging up? is there a pinched/kinked line somewhere? maybe bad vacuum from fpr? maybe fpr itself is bad? just guesses. also u might wanna check the relays. ive seen them go bad (but very rare times) where relays were bad n it would starve engine for fuel unless accelerating/higher than idle rpm's.

 

Cheers tacobo670,

I've tried 2 filters, checked and flushed all the lines, and replaced a few feet of bad line, replaced the fuel circuit relay as well. I'm really running out of ideas though, a lot of hours work, but at least I'm not paying toyota!

 

seeing as how its going, u may have to pay them to get it checked out. could the idle air control valve/throttle up be dirty? or MAF?

 

I've had a Walbro fuel pumps on 2 different cars (STi and Evo) both of them whined, its pretty common and not really a problem...whinebros. I'd call URD and ask if there is a specific pressure your regulator should be at or just remove it. Not sure on oem pump lph, sorry.

 

I dare say they would be. I'll head out and give them a clean up.

 

just cleaned the throttle body out, it wasn't too bad.

 

Have you checked your plugs yet? Ensure gap is .039-.043 and check the condition of them.

http://www.tacomaworld.com/forum/technical-chat/30479-how-spark-plug-change-1-gr-fe.html#post469268

Do you have any other engine related mods aside from your fuel system? If not I'd go back to stock in that regards.

 

If you are running 38 PSI I'll assume it's fuel injected. The regulator is part of the system it is factory set to return any fuel to the tank above the set pressure. Now if there is a restriction in the return line (smashed line? or even a faulty regulator) the pressure will increase. The fuel mix relies on an accurate set pressure so if the pressure is beyond the factory set it will run rich ie. will use more fuel. I don't know the volume but any high pressure pump will deliver more fuel then is needed and a good part of it is returned to the tank. I'm not sure your's has a vacuum opperated pressure boast for high demand some do but that can also be suspect.