I've been having some on and off fuel pressure/lean issues. The truck was parked, and would not start back up; I have no fuel pressure according to my guage. I checked the fuel fues, the fuel pump relay has been changed, I checked the fuel cut off switch under the kick pannel. I figured it was the pumps going out/went out. So, tonight I swapped the pumps out for some Walbro 255's The truck still won't start, and still has no fuel pressure

The fuel filter has probably got 500 miles on it. Could the fuel pressure regulator have failed? I am lost; I was going to check the voltage at the fuel pumps, but ran out of time tonight.

 

Casey, here is some thing to try. Go under the truck and disconect the fuel line that goes into the fillter. Have some one get in the truck and just turn the key on but don't try to start. If fuel comes out then you know you have fuel that far. work your way to the fuel rail take the little valve out on the passenger side have someone turn the key on again fuel should come out if not then back track.


Suavy

 

Maybe JDM will chime in and fix you right up

Sorry I could not resist !!!!

Bob

 

Well; just went and double checked. I can hear/feel the fuel pumps come on, and cut off in about 5~10 seconds with turning the key on. So, the pumps are getting power. I see no way the the filter stopped up 100%

Tommorow I'll do like Sauvy said and take the fuel filter lose, but I have a guage on the rail and it says "0" so I know no fuel is getting there.

I didn't look, but is the regulator on the incoming or the return side? Which I guess even if it was on the return side it could cause a air bubble problem.

 

Sorry; double post.

 

Maybe it's your TOON..hehe.

Suavy's idea is a good one. Start at the filter. If you are getting fuel there.......start heading north. Good luck

 

Casey, you might want to check your fuel pressure regulator, it might be stuck open returning fuel to the tank.

Charles

 

When I change my fuel pumps out the truck started then died. I checked every thing and nothing! I called JDM who supplied the pumps and they said to check the fuel lines in the tank. I B and moaned but did it and low and behold one of the lines had poped off. I used a screw driver to tighten them however the second time I replaced the clamps and used a small socket wrench. Problem solved.


Suavy

 

I used a stocket, and got them pretty tight.

If it was stuck open wouldn't I see some pressure?

 

I would think that you would see some pressure. Lets make sure you are not vapor locked.

If the pump turns on and shuts off it seem that it may think it's up to pressure. If it was hung open it would keep on pumping until it senced resistance. I would think, I'll check the service CD real quick.

Suavy

 

Casey our fuel pressure regulator is on the fuel rail it self. you could always pop it of and turn the key on to see if you get fuel of here is the procedure for that.

Removal and Installation

WARNING:
Do not smoke or carry lighted tobacco or open flame of any type when working on or near any fuel related components. Highly flammable mixtures are always present and may be ignited. Failure to follow these instructions may result in personal injury.

WARNING:
Fuel in the fuel system remains under high pressure even when the engine is not running. Before working on or disconnecting any of the fuel lines or fuel system components, the fuel system pressure must be relieved. Failure to follow these instructions may result in personal injury.

1. Relieve the fuel pressure. For additional information, refer to «Section 310-00A».

µ 2. Remove the fuel pressure regulator (9C968).

1 Disconnect the vacuum hose.

2 Remove the snap ring.

3 Remove the fuel pressure regulator.

µ 3. Remove and discard the fuel pressure regulator O-rings.

4. CAUTION:
Use O-rings that are made of special fuel-resistant material. Use of ordinary O-rings can cause the fuel system to leak. Do not reuse O-rings.

Note:
Lubricate the new O-rings with clean engine oil to aid installation.

To install, reverse the removal procedure.

Here is the procedure for pre pressure relieve...

Fuel in the fuel system remains under high pressure even when the engine is not running. Before servicing or disconnecting any of the fuel lines or fuel system components, the fuel system pressure must be relieved to prevent accidental spraying of fuel, causing personal injury or a fire hazard.

µ 1. Remove the Schrader valve cap and install the Fuel Pressure Gauge.

µ 2. Open the manual valve slowly on the Fuel Pressure Gauge and relieve the fuel pressure.

l This will drain some fuel out of the system. Place the fuel in a suitable container.

 

I would also check the fuel pump relay. I have seen this many times.

 

How did you make out Casey?


Suavy

 

Ready to burn this truck!

I am lost now. Tonight I started out by pulling the fuel filter, and I had no gas flow there. So, I back up to the tank. I unplug the power supply harness and check for voltage. I found 3 hot wires. There were two rows; one row had 2 wires and both were hot about 6.6 volts each. The other row had 4 wires and one wire on the end was 11.6 volts I beleive. So, I plugged it back in, and suddenly had a fuel going everywhere! I unplug it quickly, and switch the key off. Plug it back in, and the truck start right up. At this point I figure I had a bad connection. Let the truck run; Fuel Pressure looks good. Ran it for about 3 mins, but never drove it. Shut it off, decided to restart it.............It wouldn't start! But, the Fuel Pressure now wanted to inch up pound by pound to about 20 pounds. Tried cranking, but wouldn't. With the cranking the fuel pressure dropped, but still wanted to inch up??? I cycled the key about 10 times, and it suddenly primed up and started fine. Started/stopped it about 10 times and it was all good. I started cleaning up, and about 10 mins later I tried to start the truck. Again it wouldn't start. No fuel pressure again. After about 20 key cycles it primed and started again like before.

I am lost; it has to be something electrical, but I am not really sure where to look.

 

Something to add; I had one code in the computer. It was P0230 which was:

P0230 Fuel Pump Primary Circuit Malfunction

What does that mean?