Q8y_drifter

Just wanted to know if installing an aftermarket fuel pump (such as a Walbro 255) has any ill effects on the rest of the fuel system. I will of course be retuning for the new pump, but I simply wanted to know if it will damage any other parts in the fuel system since the pressure will increase.

mikelr

iTrader: (1)

May I ask why you think you need to upgrade to an aftermarket pump?

Q8y_drifter

I took my car to get it tuned at an Uprev tuner and from 6K RPM onwards the car kept leaning out (all the way to 15:1). It wouldn't respond to the AFR targets that are being commanded. The tuner said it's the fuel pump, which needs to be replaced with a new one. Personally I think he may be right, especially since my last 3 or so fill ups I was forced to run the car till the low fuel light came on. That probably heated up the pump and weakened it.
Now the reason I wanna go with a Walbro is because it's only $85 (stock pump assembly is over $300) and i can still use it when I get my car FI'ed. However if the Walbro pump will give me issues then I'll buy a new stock pump.

DmfG37sTT

If its only 85 bucks why not get it. Even if it doesnt help at least you will have one when you F/I.

Q8y_drifter

I'm just afraid it might raise the fuel pressure and possibly shorten the life of the injectors.

kyle@stillen

Have you changed injectors or added forced induction?

Q8y_drifter

Nope just intake/hfc/catback. stock injectors

kyle@stillen

I don't think you need to swap the fuel pump. We have done thousands of dyno pulls on these cars and we have never seen the need to go to a larger fuel pump with the modifications that you have.

Your best bet will be to hook up a fuel pressure gauge. If your fuel pressure drops during your dyno run then you may need a pump. However, I would be extremely surprised if you do need one.

Q8y_drifter

what should the stock FP be? I got a new pump assembly from the dealer anyway. I'll replace it and see what happens. I'll keep the old assembly for when I get my SC kit and swap out the pumps

One last question, do I HAVE to relieve the fuel pressure before swapping out the assemblies? I was told to remove the fuse for the fuel pump and start the car till it stalls. I can't seem to find the fuse though?

Thanks for your input!

kyle@stillen

I can't remember exactly what the fuel pressure should be, I would have to pull up the owner's manual to confirm but it's around 51-55 psi.

That will definitely empty the fuel from the lines and will relieve pressure or you could just pull the line off and put a rag around the end of it when you disconnect it. The pressure will release instantaneously and you will only lose a little bit of fuel...not very much at all.

Wish I could help you find the fuse but I really don't want to tell you to look anywhere because the cars vary so much from country to country...chances are I'll tell you to remove a fuse and your windshields will go crazy! LOL

Q8y_drifter

I'll check with my tuner and see if he can monitor the FP during the dyno runs.

I guess i'll just get a bucket and cover the place with shop towels

LOL no problem. Thanks a lot! Really appreciated

Q8y_drifter

This is for future reference I guess.

I replaced my fuel pump and everything worked out perfect. The engine no longer leans out above 6K and I can actually hear the pump now during start up lol.

kyle@stillen

Very interesting! Did you go with a larger fuel pump or just a factory replacement?

Q8y_drifter

Just a factory replacement. I disassembled the original worn out fuel pump assembly to install a walbro pump later on That way I still have a stock unmodified assembly If I ever go back to stock.

kyle@stillen

Oh ok that makse more sense then. So your factory pump was just wearing or worn out...I was going to say, if you've seen something we havent seen I'm concerned! LOL