After fuel filter change, should I hear the lift pump?

[Old Account - 243]

I changed the fuel filter tonight just the same as the previous three.

The first time I cranked the engine, it fired right up and I know this was fuel already in the lines.

I cycled the key off and on about five times but never heard the lift pump. Cranked the starter three or four times and then cycled the key off and on again. No lift pump buzz. Cranked the starter again and the engine fired up the third time and ran fine.

It is odd that I did not hear the lift pump; and, I would have thought that the engine would not start if the lift pump did not prime the fuel pump.

What's up? bad lift pump, really quiet lift pump or bad hearing...

243

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99 QC 2500 ST 4X4 SB 24V/5speed 3. 54/LSD Driftwood/Agate
Walker 21468, VDO, Bridgestone 285/75/16 MT's, RS9000's, Hella 500's

-- email address removed --

 

[Vaughn MacKenzie]

243, that is odd, my lift pump runs almost every time I bump the starter, without starting the engine. Is that what you did? You may want to check your wire going to the lift pump to make sure it isn't loose, and that it's getting 12V. It is a pain to get to the wire though.

But before you start disconnecting your lift pump wire and checking the voltage, try this: Raise your hood, then get in and bump the starter. Then jump out and listen under the hood. The pump runs about 10-15 seconds so you should have time to hop out and listen for it.

Any time I've changed my filter I bump the starter and let the lift pump run for 2 cycles. Then my engine starts instantly and runs smooth.

Vaughn
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'01 2500, QC SB 2wd

 

[HVAC]

My experience is that while I may not hear the lift pump when I turn the key to on, I always hear the pump when I bump the starter.

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Nowel/Performance Diesel

 

[Royal]

The lift pump will not run if you just turn the key to ON. You have to energise the start circuit by bumping the starter,without starting the engine,and the pump should run for approx. 20 seconds.

 

[Alan Reagan]

Mine runs without bumping the starter. If I turn the ignition switch to the on position and the "Wait to Start" light illuminates, my pump will run. It only runs for about 3 seconds. However, it either has pressure sensing capability or timeout capability because if it runs and the switch is turned off and back on, the pump does not operate a second time unless there is significant times between putting the switch to the on position. I haven't tried bumping the starter at that point to see if it will turn on the pump.

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2001 HO 6 spd 2500, 4. 10 LSD, Towing Package, Electric Brakes, SPA EGT/Boost Gauges, Running Boards, Fog Lights, Real Backup Lights, Running Boards

[This message has been edited by Alan Reagan (edited 01-02-2001). ]

 

[Old Account - 243]

Last night, TXRam reminded me that the lift pump did the same thing when we put my injectors in. He shook the wire on top of the fuel filter canister and the lift pump began to work again. (possible short)?

This morning, it was pretty cool so I turned the key on planning to let the "wait to start" light go out. The lift pump started buzzing as usual.

I have no idea why it's acting up but I'll check the connections at the lift pump first.

What are the wires at the top of the fuel filter canister for?

243

 

[Archive]

Originally posted by 243:
What are the wires at the top of the fuel filter canister for?

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Those wires on top of the Fuel Canister go into the Fuel Heater. The Water in Fuel sensor wires are towards the bottom.

This is on my 2001 tho.

 

[highland]

Just changed my fuel filter three weeks ago and my transfer pump would buzz - but it would not refill my fuel filter canister. Still got the truck running but I had the dealer check fuel pressure off the tranfer pump. They said "you were right. It was bad. " and replaced it under the 100K engine warranty. I would get it checked if you suspect it may be bad. Also, as noted above, you have to "click" the starter slightly to get the lift pump to activate.

 

[TowPro]

Like everyone says, you have to hit "start" then let the key in run and you will have the lift pump running.

Now mine will make very little noise when the filter bowl is empty. And it takes about 20 cycles of the pump to get it started again, guess I need a lift pump!
once its primed, you can here the lift pump

 

[Royal]

I think a lift pump pressure gauge should be standard equipment on all diesel RAMs. I would not be without my gauge. Don't cost much
and you won't be guessing if your pump is OK.