99 Ram 1500 Won't Idle

[mdwalker]

99 dodge ram 1500 5.2 liter that won't idle. Motor will idle for a few moments if rpms are increased. While sputtering there is a loud sucking sound at the back of the TB where the IAC is located. I replaced the IAC with no change. There are no codes showing up. There is 102K mile on the truck and as far as I know nothing but the water pump, the speed sensor and the ABS sensor has been changed. I would appericate any ideas.
Thanks

Update: I checked the fuel pressure at the fuel rail and only had 10 PSI. Replaced the fuel pump assembly and rechecked pressure with no change. I test the TPS and the MAP sensor per Haynes manual. TPS checked out fine. The map did not increase in voltage as it should have. Will replace the MAP sensor tomorrow and see if this fixes the problem. If not will probally keep throughing parts at it til its running correctly. If anyone has a better plan feel free to let me know.

[bluetip]

Originally Posted by mdwalker

99 dodge ram 1500 5.2 liter that won't idle. Motor will idle for a few moments if rpms are increased. While sputtering there is a loud sucking sound at the back of the TB where the IAC is located. I replaced the IAC with no change. There are no codes showing up. There is 102K mile on the truck and as far as I know nothing but the water pump, the speed sensor and the ABS sensor has been changed. I would appericate any ideas.
Thanks

Update: I checked the fuel pressure at the fuel rail and only had 10 PSI. Replaced the fuel pump assembly and rechecked pressure with no change. I test the TPS and the MAP sensor per Haynes manual. TPS checked out fine. The map did not increase in voltage as it should have. Will replace the MAP sensor tomorrow and see if this fixes the problem. If not will probally keep throughing parts at it til its running correctly. If anyone has a better plan feel free to let me know.

you replaced fuel pump and got no change in pressure ? 10 is too low you may have restriction in line somewhere

[mtlone]

I have been through this with my 99 Quad Cab, here are a couple suggestions.

1) look down through you throttle body and see if there is oil on the bottom of the intake, if so you will need to replace the pan gasket on the bottom of the intake (very poor design by Dodge) but not a bad job, book calls for 6hrs did it my self in 7.

2) Check you O2 Sensors you have one before the cat and one after. The best way to find it was put a good scanner on your truck and run it watching the voltage on you O2 sensors.

Good luck,
Mtlone

[mtlone]

I have been through this with my 99 Quad Cab, here are a couple suggestions.

1) look down through you throttle body and see if there is oil on the bottom of the intake, if so you will need to replace the pan gasket on the bottom of the intake (very poor design by Dodge) but not a bad job, book calls for 6hrs did it my self in 7.

2) Check you O2 Sensors you have one before the cat and one after. The best way to find it was put a good scanner on your truck and run it watching the voltage on your O2 sensors.

Good luck,
Mtlone