Greguw

Hey guys ,
The old 12 valve is pushing 200k with the original lift pump . I have been noticing its been taking more than one crank from time to time to get the old girl fired up ... Are there any signs when a lift pump is on its way out ...
Once she is fired up she is running fine except I did notice today after a good 180 mile run she was idling around 650 and a little ruff at idle but not bad but I think something is on its way out .
I did the overflow check about 40k ago ... Fuel filter is fairly new . I'm going to get a new fuel filter and do the lift pump , I would figure its on a limited life time right now .
Any thoughts on this ?

Thanks

greg

9812vram

I'd say at 200k, the lift pump has done well. Harder starts from time to time could be air in the lines, shutoff solenoid sticking, or fuel draining back through the check valves in the lift pump. Does it make a ticking sound? A sure way to tell if the pump is good is to plumb in a fuel pressure gauge, but at this point I don't think you'd go wrong to replace the pump regardless. If you have the ball and spring style Over Flow Valve, I'd replace it at the same time.

Greguw

It did have a tick about 10k ago and I did the fuel filter and seemed to quite it up ... I'll do the lift pump , filter and check valve and go from there .
Thanks buddy !

Tate

Whats your idle at when cold and hot? Low idle will make it hard to start, and it sounds like yours is low.

The ticking doesn't necessarily mean its going to die. Mine had that ticking noise for 3 years. I just replaced it a couple weeks ago, even though it was running fine. I had the replacement on a shelf about a month after I bought the truck, back in '08.

cj360trider

is it still ticking even after you replaced the pump or did that take care of the ticking??

schoust

Just change it out. That is if you don't want to be stuck on the side of a Highway in 15 degree weather!
Ask me how I know Lol! Seriously mine quite on my with no warning at all at 175k......Then again if you feel lucky I have seen them last way longer.......

Greguw

I parked the truck til I get the parts this week ... It did have a tic but did go away once I put a new fuel filter on ... I'll just do the pump , valve and filter and hope that fixes ... Broken down on the side of the road sucks ...LOL

Thanks guys

greg

ohanahorse

Think the best price on a lift pump is at Cummins dealership (when I bought mine, it was about half o f what everybody else wanted). Also, to some searching as it's way easier to install studs when you replace it rather than using the bolts-don't remember the size)...
p

Tate

The metallic tick that I got between 1000-1300 rpm went away. The soft ticking sound by the fuel tank is present, but I don't think that will ever go away. Thats the nature of the beast. Need a smoother delivery system to eliminate that, piston pumps aren't that smooth.


The bolt size is M8x1.25mm.

Greguw

I just checked Flea-bay and guy had a Factory Cummins pump for 100 bucks with free ship so for me with my time I was ok with that , I also bought 2 of the overflow valves from Larry B ... I have a cummins powered suburban with 100k on the motor I figured I would pick on up for the beast .
I'll drop the starter when I go and do the pump makes a little more room ...With the motor out fuel pump goes in really fast ...LOL
I'll tackle that pump on saturday morning .

infidel

Cummins and Geno's both sell OEM pumps for about $100.
Auto parts stores sell inferior generic pumps for way more.

I don't know about a failed pump forcing you to walk.
When mine went at 275k miles the engine ran fine except at over 2000 rpm or under heavy load.
The P-pump will suck fuel on it's own.

What helps immensely when replacing the pump is to toss the stock pump bolts and replace with a pair of 8mm x 30mm x 1.25 pitch studs with nuts.

9812vram

When I did mine, I just rolled the engine over so the pump cam lobe had the low side facing the plunger - waaaay easier to put the pump in (which I did from the top), no studs needed....

My lift pump had the ticky tick too. It started just after I bought it. Under load the truck smoked gray and was definitely under powered. I was scared I would get left on the road, so I replaced it when I did all the other stuff. No more tick or gray smoke and lots of peace of mind!

Tate

I will say my smoke output went way up with the new lift pump. I did 520rwhp on a bad dyno with my current setup and the old ticking lift pump, cleaned up very well on the top end on the street. Now its a heavy black smoke. Haven't experimented too much with it since I'm out of town and don't need to chance grenading my G56. The old pump did do 550rwhp with SDX delivery valves. I was down 20 psi of boost on the dyno, I'm sure it had 600 in it if it had a proper brake.

Greguw

Did the pump , fuel filter and check valve ... made a big difference , Idle came up atleast 100 rpm , more smoke and have not seen any hard starting issues like it had ... It actually seems to fire even faster than before .
Turns out someone did replace the pump before and it was a carter ... not sure there track record but I was pretty happy with my choice .
After I installed the fuel pump I found the squeeze clamps that are on the fat hose that feeds the fuel heater housing were getting weak .
I had a hard time priming the motor at first and did a second glance and noticed a slight drip .
So I replaced the crappy squeeze clamps with a a couple of smooth band clamps and primed up right away .
Had the truck out all day saturday and the old girl ran like she was new .

9812vram

Good to hear! Glad you got 'er fixed!