Engine/Transmission (1998.5 - 2002) 2000 ram 4x4 ,5spd lift pump question?

[aviatorman]

Truck has been hard to start. Suspected fuel delivery problem. I click the starter to make the pump run for the 28 seconds or so and that initially worked ok. Further checking revealed that the pump would not come back on if you attempted to click the starter again. So I'm guessing that something is interrupting the power to the pump and it's intermittent. Don't have pressure guages so can't tell if the pump is working when going down the highway. Is there a relay or something that could be causing the intermittent operation? I believe that the lift pump is supposed to run constant any time the engine is operating. Anybody have this problem in their past experience?

 

[SAndreasen]

there are several things that can cause the pump not to run . ive seen it when the lift pump wouldnt always run when bumping the key every time . the first thing to do is get a gauge and see if your getting fuel psi to the injection pump . have you changed the fuel filter lately?

 

[SnoKing]

Key has to be turned off between bumps! Snoking

 

[NIsaacs]

How many miles on the lift pump? Is it the oem type in the oem location? The next time it don't run and you think it should be, thump on the pump with a plastic screw driver handle. If that makes it run then change it.

Nick

 

[aviatorman]

How many miles on the lift pump? Is it the oem type in the oem location? The next time it don't run and you think it should be, thump on the pump with a plastic screw driver handle. If that makes it run then change it.

Nick

Lift pump only a year old. Just relocated it to the driver side frame rail with Geno's kit. Fuel filter changed 3K miles ago. Does the ECM or ACM have any input to the lift pump while engine is running down the highway?

This will close the case of the intermittent lift pump: When troubleshooting, never assume anything, because when you spell "assume", it reads like this " ***-u-me. It makes an *** out of you and me. I assumed that all the battery connections were in good shape and they in fact were not. High resistance on the left battery positive post connections were enough to interupt the power to the lift pump (and other sensitive electronic hardware relays). Cleaned all battery connectors and the problem has gone away. Thanks to all who read my post and responded.

 

[SnoKing]

Lift pump only a year old. Just relocated it to the driver side frame rail with Geno's kit. Fuel filter changed 3K miles ago. Does the ECM or ACM have any input to the lift pump while engine is running down the highway?

The fact that an OEM Carter lift pump is only a year old does not mean that it has not failed. Monitoring fuel pressure with a gauge on the 24V is very important.

 

[BigPapa]

The fact that an OEM Carter lift pump is only a year old does not mean that it has not failed. Monitoring fuel pressure with a gauge on the 24V is very important.

Signature material right there......