fuel pressure

[PeterH-350LE]

I wonder if one of you 345 owners could check your rig if you have a fuel pressure regulator in your fuel line. It should be located after the mechanical fuel pump on the motor, before the carb.
I bought an electric fuel pump to add to the rear by the tank. I don't have any problems with fuel delivery when driving, just when the MH is sitting for a few days I have to crank the engine for some time to get fuel to the carb. After the initial lack of fuel, it always fires up on the first crank, even the next day.
I am going to wire the pump to a switch, so I can flip it on to start the motor. I do not want to keep it on without a fuel pressure regulator, because I am afraid I am going to get the float needles all upset.
If you have such a regulator, I would be interested in the psi rating.

[PeterH-350LE]

Did it, installed the fuel pump and wired it to a new switch on the dash. Since I did not start it for three days, I turned the pump on, waited a few seconds and it fired up on the first crank without touching the gas pedal. Test driving revealed no difference with the pump on or off.
While I was running new wires, I also installed a new light on the dash which runs to the pressure regulator of the airbag compressor. Now every time the compressor comes on, the light goes on.
Nice early warning feature for airbag/lines leaks.
Alan, while I was running wires, I traced the yellow air compressor wire. It runs straight to 30 amp fuse in the GM fuse panel (ignition on only)

[ALANSD]

I was trying to do that just yesterday- I have 3 different layout charts for the fuse block. I do have the yellow wire plugged in to the block directly, as i recall it was not fused.
I will check it again. I managed to fix the distribution control panel light- easier than I thought.
Also I read somewhere about checking your carb floats as they become saturated after a while and mes up the fuel regulation.

[thenewkid64]

Peter,

I had a problem like the one you describe with a 7.9 Liter Diesel. I quote, "I don't have any problems with fuel delivery when driving, just when the MH is sitting for a few days I have to crank the engine for some time to get fuel to the carb. After the initial lack of fuel, it always fires up on the first crank, even the next day."

What I found was the water sepraration unit was allowing air into the fuel line and fuel was running back to the tank. I bypassed the water sepration unit with a brass barbed connecctor and 2 hose clamps and the "hard start" problems were gone. So my advice to you would be to check for loose hoses or a very small leak that is allowing air into the line. In the mean time it sounds like you have come up with a good fix.