Fuel check valve?

I was told to install a fuel check valve in fuel line before I change my fuel pump.Its a 96 2.7liter.I ordered a fuel pressure regulator if this dont fix it I was gonna install the fuel check valve.Do I install it before the fuel filter or after it?

 

What’s the truck doing?

 

Missing a LOT of context here... why are you being told to install a check vavle or a pressure regulator?

But I would venture a guess that none of that stuff is actually necessary to fix any issues you’re having. Maybe only mask problems you’re having...

 

Well it started running rough going down the road first.So I thought I maybe had some bad fuel,so I put some 93 octane BP fuel in it and changed the fuel filter,,in which it needed.The one under the intake manifold.When I took it off and drained it in a bowl,brown fuel came out of it.Next it ran decent for a couple weeks,then started a rough idle on start up till it warmed up (20) sec it would smooth out.Then it started running rough at stoplights,like it was flooded out.New plugs,cap,rotor,wires,and just changed fuel pump 10,000 miles ago.This is my daily driver,been doing a lot of reading and research on this problem.Ive come to the conclusion it's the fuel pressure regulator or a bad check valve in fuel pump.Anymore suggestions are appreciated.

 

Have you replaced the fuel pump relay? That was the problem on my old truck. They seem to call it a circuit opening relay under the dash at the fuse block. Photo courtesy of our friends at ttora

 

Unless you are replacing a malfunctioning part, adding a check valve or whatever to a system that wasn’t designed with one isn’t going to do anything, except temporarily mask the problem (if it does anything at all).

You need to figure out where that brown fuel is coming from.

Rusty tank?

 

I changed the filter under the door last year.I took it off to verify my fuel pump wasnt bad,and its pumping clean fuel.The fuel pump is pumping fuel in a bucket as I turn the motor over.The motor is turning over,but flooding out and not starting,then I start smelling fuel like its flooding.

 

Leaking injectors, maybe

 

Or an EVAP issue

 

I'd venture to guess that too they made a world of difference ony truck

 

Black Dog please explain the EVAP issue

 

I seen the EFI relay in the fuse box under the hood,could this be causing this issue?I know I need a volt meter to check it.

 

CEL on?
P0440, P0442, P0446. ?
If No please allow me to pass on explaining EVAP.
TYIA

 

Check every vacuum rubber hose for dry rot and replace (if you wipe the outside of a hose and black shit comes off... it’s toast)

 

I have to agree. A check valve just keeps fluid going in only one direction. It shouldn't be necessary.

 

I have no engine light on so I cant get a code.

 

Do have a code reader? Whats the coolant temp on startup?

 

Does the light come on with key in on position and go off on start up?

 

Yes Black Dog

 

I'm about to try and start my truck,got new fuel pressure regulator installed,cleaned throttle body,new plugs,,(incase I fouled one out when trying to start last time and MAF sensor cleaned.What do you guys use to spray in throttle body to start it? I've use wd40 in a generator which is flammable.