Priming fuel filter

[Alex Macias]

I have always done the crank it till it starts method after a filter change. Well today that hasn't worked yet. I emptied the filter bowl and can't get it primed now. Any other way to prime? I've searched the board to no avail.
1997 6.5 TD
Tahoe

[Hubert]

What are you talking about priming the IP or the fuel system and purging air at filter top?

If I understand you correctly you have never burbed the fuel filter of air at reinstall and just cranked it up???? While that may be possible with a 97 that the lift pump works while wait to start it is not OK. In fact that should be warned against.

Is your lift pump working? You might have air locked the IP or damaged it is it original at 200K miles? It must have diesel fuel to lubricate it at all times.

[diesel65]

Most likely the lift pump has failed, it is located on the inside of the frame rail under the drivers seat.
When you first turn the ignition key on and the glow plugs are cycling the lift pump should be running.
There is a priming wire between the firewall and the engine compartment fuse box, it is a red wire with a brown terminal shield on the end, it is bundled with the other wires. Apply 12 volt to this wire and the pump should run, open the filter bleeder and fuel should squirt out.

[Alex Macias]

I think that the lift pump is the culprit. I do not hear it when the glow plugs are cycling. Does Autozone carry them?

It is not the original IP--It was replaced at 100K. I changed the lift pump about 8 months ago--I guess it's time for a new one.

I was not able to find the wire to fire the lift pump. Any more details for next time? I did find a red wire with a black connector labeled P.E.D.--could that be it?

In past filter changes I would purge the air by opening the air bleed on top of the filter and cranking until I saw fuel come out. Is this the wrong method?

I don't think the lift pump will fire by trying to crank in a drive gear.

[Hubert]

On a 97 the lift pump should run with key on run for approximately 5-15 seconds (while wait to start). You should not need to crank it.

You should purge air at filter and make sure IP has good fuel supply before cranking (key on start) the engine.

Do a search you can also jump some pins under the hood in the fuse block its been posted several times. I just turn key and run around and shut air bleed or get someone to turn key for me.

After you get the lift pump fixed post back if it does not crank.

[Buckle]

I usally just pulled my old one out and plunked a new one in...am i doing this wrong then?

[Hubert]

I usally just pulled my old one out and plunked a new one in...am i doing this wrong then?

That is not a good practice. It allows all the dirty diesel fuel to come into contact with the pickup going to the IP. Dirt or contamination could stick to the center pipe. Also installing new filter some dirty fuel might get on the filtered side of the element and can get to the IP. The fuel in the filter bowl is a concentration of the crap that the filter trapped out of the fuel system. No since in keeping a cup or 2 of at a bare minimum is suspect fuel.

Read a few threads on filter change for more opinions and tips. I learned these from reading the page.

Basics:
Open fuel cap, purge some fuel out by opening water drain and air vent and blowing fuel out with very low air pressure. Then remove old filter. Turkey baster/vaccum old fuel out. Clean bowl out with rag. Install new filter. air purge.

[ff43sc]

I have a 95 6.5L, and I found that if you put the shifter in Drive and turn the key to the crank position, this will also cause the lift pump to come on without cranking the engine over, you can slightly hear the lift pump from inside the cab with no other noise, if this works on your truck, open the bleeder and hold the key on until you get a steady stream of fuel, this will get rid of the air and hopefully "flush" any floating debris out too.... and will save wear and tear on starter or overheat it...

[DmaxMaverick]

I have a 95 6.5L, and I found that if you put the shifter in Drive and turn the key to the crank position, this will also cause the lift pump to come on without cranking the engine over, you can slightly hear the lift pump from inside the cab with no other noise, if this works on your truck, open the bleeder and hold the key on until you get a steady stream of fuel, this will get rid of the air and hopefully "flush" any floating debris out too.... and will save wear and tear on starter or overheat it...

That's a neat trick, and many of us have been doing it for years. Problem is, it's unique to 1995 models.

[Warren96]

I wonder what the General was thinking when he changed this wiring to the lift pump so many times over the years.......I can think of at least 3......1993 1994 1995 96?

[Alex Macias]

I plunked in a new fuel lift pump and got it going in no time. Thanks for the help, all. This is an invaluable resource.

[seth_95]

When I change a filter I take the old one out, open the air purge valve ( the one used to drain out water). Close that valve, then I install a new filter and then use a vacumm line hose to put on top of the air purge valve (on top of the fuek filter) then I open the relay box under the hood and remove the fuel pump relay. Then I jumper the bottom left and the top right connectors and that runs the fuel lift pump, I wait for fuel to start comming out of the hose then I shut air bleed valve and remove jumper. Install the relay and then start the truck. I let it idle for 5 mins and thats it. Never had a problem and using the vacumm lines keeps the engine from getting fuel all over it!