^ I'll have to see about taking pictures when I do mine...

I was just told by someone that it was possible to access the fuel pump without removing the tank by removing the rear seat bottom and going through an access door. I know this door is there because I saw it when I made my fuel pump rewire.

Plate labeled 'J' in my pic below. I'm not sure if it's big enough to take out the pump and remove the ball and spring from the regulator however. If so, that would make this job muchhhhh easier. Anyone know for certain if you can do a fuel pump this way..?

 

No that wont work. Tank definately needs dropped.

 

Ahhh man. coopercharge on here claims he did his friends pump through there and they were able to remove the entire pump and sending unit from inside the car. Once the whole thing is out, the ball and spring should come out no?

If the tank needs dropped, can you explain a quick high level howto?

I need an EVAP fitting too

 

the tank is easy to drop. four bolts and then disconnecting the fuel lines and junk. Make sure to have as little as possible gas in it when you do it.

 

Ya that doesn't sound bad, I just don't want to drop the tank if everything can be pulled out of the top from inside the car.

 

I don't see how the sending unit and everything can be pulled through that hole. The harness, feed, return, etc all on canister too.

I could be wrong. Easy way to empty tank is disconnect the feed from filter and put it in a container under car then use hpt to kick pump on.

 

Doesn't seem too bad then.

I believe there is some sort of special tool needed to unscrew the top of canister from the tank? Or can it easily be twisted off by hand or another method?

 

OK I just had my back seat out, and there is definitely no way to access the fuel pump or tank... The fuel pump wiring is under there, but nothing else. Unless there is a major year difference or it was a Redline difference or something, there is no way to get to the pump... So not sure why someone else stated it could be done. Typical css fail lol.

 

There is a special tool, but I just used a hammer and extension or something and bang at each clip until it slid apart.

 

My BRFPS kit is turning into a nightmare...

If anyone can help, I'd realllllly appreciate it!

https://www.cobaltss.net/forums/zz-p...roblem-227008/

http://www. gm sportcompact .net/forums/showthread.php/2177-Boost-Referenced-Fuel-System-(BRFPS)-Problem

 

use a hole saw to get to the tank = win

 

LOL, that might just work...

 

Hey Wes, did you have to mod your Walbro pump to flow at higher fuel pressure?

skatinboardin is having problems with his, and USMCfieldMP linked to a post about modding a ball and spring in the Walbro pump so that it would still flow over 75psi. Supposedly the pumps have a pressure relief valve in them and won't go flow at that high of a pressure.

 

This is true and why we don't recommend adjusting pressure normally. Besides that the volume of the Walbro is so low above 75psi, there would be no point unless you were trying to run 42# injectors still.

 

Which pumps do you guys at zzp recommend?

 

We have some prototype drop-in pumps that outflow the stock pumps pretty significantly. We are still in testing phases with them, but hopefully they will be available soon.

 

You guys at ZZP may not like the Walbro pumps, but it is a cheap solution to the 2004/2005 pumps that are terrible.

It fixed all my fueling issues, and I am still running mine unmodified.

And Corey, I am the one that gave USMC the link But I haven't done it yet as I didn't need to.

 

Haha good. I was just trying to help out skatin a bit. I wonder why yours handles the pressure properly and his doesn't? He'll have to do some digging to see why it's not working.

 

I am about to go see whats going on with it. Life has been busy this summer. I havent even drove my car hard for almost 3 months now. Time to get on top of this.

After reviewing some logs this 75psi makes sense because its about when I get 17lbs of boost which would theoretically be about 75psi fp. I can trouble shoot it with messing with the base pressure.

 

Yeah, I don't know.

I'm running a 58 base and now wrapping/resetting the stock boost gauge since the pulley drop. So I am going a good bit past 75.

My stock Walbro is keeping up just fine.

 

Im going to bump this thread-

Im still having fuel problems. I run out of fuel at 6500 (fuel isnt cutting just going lean). BRFPS/80lb/E85/TVS/2.85/Walbro342.

I modded the pump by precharging the spring so it does not let off fuel pressure above 75lbs, this helped a lot but didnt fix the problem. I think I got a weak or bad if you would, fuel pump.

So whats next- Take my chances on another walbro and cross my fingers or try something different. With a little reading it seems like the bosch 044 flows really well but at a little higher price. Which I could care less about, I just want my fuel to be correct.

WSFrazier do you start running into problems below half a tank? Once I hit half a tank wot pulls will go lean very fast and if I hit a quarter tank its hard to drive the car to the gas station. Which also tells me I got a bad pump.

 

Nope, I've ran the car down to below E with no problems. My Walbro is holding out fine, and I'm running smaller pullies than you.

Around 7300ish my IDC's are in low 90s. AFR holds perfectly what I command.