99 7.3 f350 oil pump/ ICP pressure

[maxsams9]

Hello, I have a 99 f350 7.3 320,000 miles. Bought it at 315,00. It has banks cold air, banks power elbow 4 inch exhaust, power hungry 6 position chip and a edge insight.

Couple things. Just off idle it wants to stumble or die. I can catch it. Once it is past 1200 rpm's it does fine. Also, backing up, when I let off throttle it wants to die. Changing the fuel filter seems to help this, but only for a short time.

Wondering if this would have anything to do with low oil pressure for the injectors at idle. The insight shows low ICP pressure until the rpm's come up. 400 to 600 psi. After 1200 rpm it goes up to 1200 or so psi.

Am I in need of a new oil pump? I'm not aware of any maintenance done on the engine other than what I have done. I'm sure the pump and injectors are worn out. I have replaced water pump, belts, hoses, cleaned intercooler hoses, new clamps, etc.... Has good boost.

I have taken the tank off and cleaned it out. All looks well with the tank.

I have a few other questions about the truck, but would like to explore this one first.

Thanks for all help!

[cleatus12r]

Couple things. Just off idle it wants to stumble or die. I can catch it. Once it is past 1200 rpm's it does fine.

Don't have any idea about that one....

Also, backing up, when I let off throttle it wants to die. Changing the fuel filter seems to help this, but only for a short time. Usually this is caused by a torque converter clutch that is trying to apply due to low transmission pressure. Reverse is a very "fluid hungry" range from a transmission pump's point of view. 95-97 truck guys fight this one all the time because of the way the torque converter is controlled. It's possible on a 99-03 truck though.

Wondering if this would have anything to do with low oil pressure for the injectors at idle. The insight shows low ICP pressure until the rpm's come up. 400 to 600 psi. After 1200 rpm it goes up to 1200 or so psi. Normal injection pressure at an idle IS 400-600 RPM and it will fluctuate. The more load and RPM, the higher the pressure. It should hit 2500 PSI pretty easily on stock tuning.


Good luck!

[maxsams9]

Thank you for your help.