Installed a walbro pump and now having issues:

1) car doesnt want to start. it seems like a problem with fuel delivery. The car will only start after 4 attempts of turning the key towards ignition. When turning the key to "on", you can hear the fuel pump working.

2) When the car finally makes it to the highway, I am restricted from accelerating with half throttle position (and the service engine light comes on). Also when I actually get on it, the car falls on its face and jerks as it moves (very similar as to how a car would act if it was running out of gas).

3) MOST IMPORTANT ISSUE:
Three people I know said "your stock fuel regulator is probably having trouble handling the high fuel pressure from the walbro pump". Did I miss something? Do I need to upgrade any fuel regulators when installing a fuel pump? anything else besides regulators?

What is even more confusing is that a mechanic I know at the pontiac service department told me ls1s dont have fuel regulators but instead have purge regulators. The first thing I decided to do is replace the fuel filter and go on from there.

In the meantime, do I have a "bottle kneck" in my fuel system? Im worried because I have nitrous on the car (see mods in sig).

 

You should not use a fuel pump designed for a return type fuel system in a returnless system such as your '02' . If this is the case here, your fuel pressure is way too high causing you to run too rich. Also, the pumps days are numbered.

 

if it's a Walbro then it's not a return style and it's a replacement intank pump....you may have kinked the rubber pump hose when you installed it or maybe the hose is leaking

 

Have you tried checking the fuel pressure you're getting?(not to informed on ls1's.) They have a schrader valve you can get to right? I dunno I'd check fuel pressure first.

Mikey

 

Are all Walbro 255s for returnless systems? But you could be right in this example.

 

fuel pressure will be tested, fuel filter will be replaced.

What needs to be replaced upon walbro 255 install?

 

Sounds like your fuel line is kinked or the fuel pump tube that hooks from the pump to the plastic bucket came off or is loose.

 

Check your fuel pressure!!!!!

 

sounds like the hose clamp could be loose on the pump too.

 

where is the returnless style fuel system in a 2002 Z?

all ls1 f-cars are return systems, but only have 1 line to the rails, there is a T fitting at the back of the car next to the fuel filter, that goes back to the tank. The regulator is mounted in the tank. All fuel upgrades can be treated the same as any other car, with a return line. Just be careful about overpowering the regulator with a high pressure/volume pump.

Ryan

 

everything in my fuel system (regulator, fuel lines..etc) is stock besides the fuel pump.
The pump I now have is a walbro in tank pump.

Am I overpowering the stock regulators with this setup?

 

Thanks slow for correcting me, was thinking Vette.

 

The vette is similar, but instead of an intake regulator, the fuel filter has 3 ports, with a built in regulator.

Ryan

 

Your regulator is fine, I would double check the installation, like the other guys said:

Make sure the hose is not crimped and the hose is not leaking from the outlet of the pump to the outlet of the tank. Check the fuel pressure with a gauge.

Ryan

 

fuel pressure gauge read 20 at idle (and startup). Pressure fell down to extremely low pressures immediately after going almost WOT (manually flipping the throttle plate open). Service engine soon light now lit again.

Having trouble finding the same mechanic that installed the walbro pump to check the fuel pump hoses ... etc.

Another mechanic offered to fix my problem for $100 but required to cut a rectangular piece through the body until he has access to fix the problem (and ofcourse repair back the rectangular piece). He said he's done it before and comes like that factory on certain cars. He said thats the only way to getting access to the fuel pump without needing a lift. Good idea or bad idea, it doesnt matter when it costs $100. He works at the pontiac service department and said they would quote me between $300-400.

It sucks *** when you have no mechanical skills.

My worst case scenario could be needing the other mechanic to fix it by cutting the piece (a.k.a. the ghetto way) .. but can someone tell me what sort of problems i'd run into if i did that?

 

i've been reading a lot on the fuel pump installs lately and noticed a divide between people who cut access doors and those who don't want to cut their car.....my car is a '98 so it's a harder in the first place, but the next time i have to change the pump i'm freaking cutting an access hole......the 98s are more of a pain because of the steel tank/filler tube, not too mention it was my first time doing anything like it, but i'm havng a heck of a time just getting the straps back on now....there's a guy on here who bought a moroso(i think) fuel door and put that over the whole he cut, it looked really sharp........

btw, who needs mechanical skills? hasn't stopped me

 

found out what the problem is. You guys were right. The hose fell off.