Fuel problem

[TurboBrian]

So I got my 86 gn running like this. Supposedly with new 42lb injectors aftermarket chip, fuel pump and a bunch of other stuff so the previous guy was definitely trying to fix the problem. My base fuel pressure is around 20lbs and maybe 25 with the vaccumm line disconnected and the pressure falls when I step on the gas, and when I turn it off the pressure on the gauge doeent hold it immediately goes to 0. I thought my bosch 237 regulator was bad so I just bought an accufab adjustable off the for sale section and a brand spanking new fuel filter and it didnt change anything. The problem has gotten worse since ive got it, it idles like junk, light throttle is jumpy and wot feels like the up pipe coupler is busted through ( its not ) ... the turbo spools up but the car falls on its face. Worst thing is I dont have a scan master or even boost gauge and on a really tight budget. I know running the car lean is a no no but can it be driven if babied? Its a daily driver. If It helps one day it was running perfect until I went to fill it up and also put gumout fuel system cleaner in it and it started back again. So my question is whats the next step? Could the sock in the tank be clogged or a fuel line itself be clogged? Any help is greatly appreciated

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[SHADOWII]

You didn't state if you have a hot wire kit installed? Check for proper voltage to the pump. You already changed f/p/regulator, and you are sure the f/p gauge is good?

 

[TurboBrian]

It doesnt look like there is a hotwire kit.. I know theres supposed to be a line with a fuse on the driver wheel well? Dont see one of those. Yes the fp gauge is good I put it on my fathers we4 and worked how it should. Im learning as I go do I need to drop the tank to check the voltage?

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[bison]

Pull the tank and fix the leak

 

[TurboBrian]

What leak are you reffering to bison?

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[SHADOWII]

What leak are you reffering to bison?

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He's referring to the low pressure you are showing, 20#s. It could also be low voltage due to a bad/melted connector or loose grd wire. Dropping the tank will give you opportunity to check it all. Hopefully it's not full.

 

[Nick Micale]

If there is 12 volts at the pump, either the connecting hose at the pump is leaking like Bison said, or the pump is bad?

Of course you could instead have a wiring issue including a bad ground for the pump.

 

[Raeban]

Well with your fuel pressure dropping to 0 immediately with the key off and low fuel pressure all around It sounds like a leak as Bison suggested.

 

[TurboBrian]

Just went and checked my voltage... Mine was 6.0-6.3 and my dad's we4 was showing 11.0 I guess time to order a hotwire kit

 

[TurboBrian]

So how do I determine if that hose is leaking when I drop the tank? Never done it before. Thanks for all of your help!

 

[SHADOWII]

You will have to remove the pump assembly from the tank. Unscrew the retaining ring and try not to damage the gasket. When you pull out the assembly, it will be obvious to you. check for cracks, cut short, or just not placed all the way "on", at both ends. There's usually very limited space to work. You can use the black chemical ties to hold and seal the hose in place. You can check your wiring connections at this time as well.

 

[Chuck Leeper]

Just went and checked my voltage... Mine was 6.0-6.3 and my dad's we4 was showing 11.0 I guess time to order a hotwire kit

Sounds like both cars need a hot wire kit.

 

[TurboBrian]

Yeah I'm gonna check the grounds and check the voltage again later today because my dad's has one and runs very good and that can't be right

 

[TurboBrian]

So the ground in the trunk was awfully dirty and corroded so I cleaned that up correctly and didn't really change anything, so I dropped the tank and all of the wiring and hoses look brand new and correct. The sock had a little fuss on it but pulled that off and tightened the hoses a couple turns each. Got a walboro 255 new and gas tank is new and clean inside but my voltage is still around 6 and the pressure still isn't holding after I turn the car off.

 

[Raeban]

If the leak wasn't at the tank or the connections by the engine and your FP regulator is good there aren't many other reasons why the fuel pressure can drop to zero almost instantly. The things that come to mind is a messed up O-ring at the FPR or even two Orings in the fuel rail cup (I have seen this) and finally leaky injectors. You can pull the plugs to get an idea of the injectors.

 

[TurboBrian]

We'll I also took my fathers kirban billet regulator off and put it on just to make sure regulator is solid and his holds his pressure so I don't think it's the o-ring...

 

[TurboBrian]

I appreciate all the help... It's been a head ache but I love the car. Idk what I'd do without this site!

 

[SHADOWII]

There only remains two things left for options, to check the plugs as previously mentioned for a leaky inj. or the pump is not holding the pressure A leaking inj. will wash down the cylinder wall/s and you know what that will mean. If not the case, first take a vise grip and gently squeeze off the return fuel line to see if the gauge holds the pressure. If it holds it will eliminate a problem w/the pump or inj. If not, the by-pass on the pump.

 

[Chuck Leeper]

Got a walboro 255 new and gas tank is new and clean inside but my voltage is still around 6 and the pressure still isn't holding after I turn the car off.

That pump won't run at 6V..Not at least fast enuf to make psi.

 

[TurboBrian]

So are you saying I need a 340 chuck?