Engine/Transmission (1998.5 - 2002) Fuel System Problems ??

[Turbo Terry]

99 with rasp and stock lift pump in stock position and fuel gauge . Pressure ran at 12 idle and 14 - 15 on the throttle steady . Now all of a sudden at idle pressure goes below 7-8 lbs and makes the hobbs switch over to the the lp but the pressure stays low even when running on the stock lift pump but when you rev it up it goes up to 15 lbs. Checked belt tension ok pulled regulator and rinsed out( thought it had some junk on the regulator nozzle) and changed fuel filter . Still the same. No codes or engine lights. Seems like the last time this happened it was the lift pump. When I bump the key the lp sounds solid and not weak or sporadic. Double HELP thanks

 

[blacksheepdiesel]

Check for air in hose to sending unit.

Godspeed,
Trent

 

[Turbo Terry]

Sending unit is hard mounted to top of fuel canister. If it was the sending unit the hobbs would not kick in at low pressure(7-8) lbs the gauge just would not work. New lift pump time. Will post results.

 

[Turbo Terry]

Well the results are in. It was not the lift pump as I still had low pressure. So i removed the regulator again and started playing the washer game. Started with two washers pressure to high -went to one pressure still to high so i went back to no washers. But in the mean time I had taken the time to really clean and scrub out the nozzle and the seat and now i once more had my nice steady 12 at idle to 14. 5 at wot. The first time I cleaned the the regulator by taking it apart for a quick rinse but I think the new ulsd fuel left a deposit in the seat that would not come off without a good scrubbing. So i hope this post will help someone in the future and not blow a great Sat fall afternoon in the diesel fuel.