Is my NEW lift pump failing on me?!
 

Disclaimer: I have my fuel gauge "Snubber" in the mail in transit right now from Tork Tek. Only a matter of days until I have my fuel pressure gauge in. I'm so frustrated with this "guess-work."

Ok, so about 1,500 miles ago I swapped in a new lift pump and new fuel filter. This past week, I noticed some 'tell-tell' symptoms of a fuel filter delta-p problem, reduced engine power / lugging / blowing blue smoke under load when the fuel pressure drops- all while uphill, but level ground and downhill is just fine.

I changed my fuel filter out yesterday with a brand new Wix. Ran great last night, for about 40 miles, then it had one instance of lugging under load, uphill, just as if the fuel filter was blocking. Happened again this morning, so I did some experimenting to get my facts straight:

-Any cruise under 2k rpm (or 70mph) can usually get past the hills 'OK'. If you step on it uphill, it quickly loses fuel pressure (or so I'm guessing) and starts to lug.
-Anything over that will drain the fuel pressure too fast and lug so badly, that you have to slow down (no other option, it's like the engine is stalling from lack of fuel) to about 60 or so until the fuel system "catches up."


Is this telling my that my new lift pump is not cutting it? I don't have very aggressive mods (sig), and couldn't think that I'm requesting too much fuel just cruising in the truck, no load on a trailer or anything?!!

I will have the fuel pressure gauge in in the next couple days. Should I consider putting a little boost pump in-line, pre-lift pump to help it out?

whats the fuel filter looking like when your changing it? hopefully pretty clean if it was only in there for 1,500 miles. also, is this something that was a noticeable change in one day, or a problem thats progressed up till now?

Started noticing it getting progressively worse over the last ~800 miles (2 weeks).

Filter is looking good, but I changed it anyway. Rather spend $20 on the troubleshooting for starters, ya know?

Update:

Again, let me remind you what's under the hood:
-New lift pump 2,000 miles ago
-New fuel filter a few hundred miles ago
-Tork Tek gauge snubber. Oil pressure gauge. nylon tubing.

This is at idle (full Op temp):

http://s110.photobucket.com/albums/n110/ApmCrx/Dodge%202500/fuel%20psi%20issue/?action=view&current=6idle15-20-flutter.mp4
Here's what's happening at 50 mph (full Op temp), fuel pressure wise:
( took multiple just so you can see it's chronically happening. these were taken one right after the other. Pedal was steady, holding at 50mph, until fuel pressure was lost, then it slowed a little. FLAT ROAD! NO HILLS!)


http://s110.photobucket.com/albums/n110/ApmCrx/Dodge%202500/fuel%20psi%20issue/?action=view&current=2cruise20-10-20.mp4
http://s110.photobucket.com/albums/n110/ApmCrx/Dodge%202500/fuel%20psi%20issue/?action=view&current=3cruise0-20psi.mp4
http://s110.photobucket.com/albums/n110/ApmCrx/Dodge%202500/fuel%20psi%20issue/?action=view&current=40psi50mph20psi.mp4
http://s110.photobucket.com/albums/n110/ApmCrx/Dodge%202500/fuel%20psi%20issue/?action=view&current=50-10-15-20-10-0.mp4


What's going on? Is it the new filter? :argh:

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What's causing the irregular fuel pressure? Air leak in system? Clogged/defective filter?

I'm trying my best to check all of the connections and lines for leakAge... But I'm gonna need this truck to pull my travel trailer in 2 weeks!

I would pretty much rule out the filter.

Need install details. How is it plumbed?

I would get a needle valve and remove the snubber (at leat temporarily), to see if that is the problem. After that, I would try another guage (0-60 psi), or test that one with air from an air compresser.

I will get a pic drawn up of how it's plumbed soon, as it's kinda spider-webbed with the WVO system. I just looked at all the lines, everything looks ok from the outside...

Gauge is known-good, but I might try another one just to be sure. Thanks

I missed the part about the WVO. Could be a clogged filter I suppose.

How do you know the guage is good? Just because its new? Do you have access to pneumatic test equpiment to check it?

Install pics would be helpful.

Like I said before, I would temporarily bypass the snubber and run fuel right into the guage.

Fuel does go right to the gauge. The snubber just has a tiny hole in it, or "Calibrated Orifice" as they call it. I purged the nylon line of air, so it's got straight diesel pushing on the gauge.
And I know the gauge is good because it's been running for the past year on my old car, accurately reading the oil psi. Plus, it's in the right range, but the oscillation of pressure is 'real-deal'. it's not just the gauge. you can definitely feel the loss of power when it goes to '0' for more than a few seconds. it makes you ALMOST have to pull off the road, but then picks back up and fuels it some more.

I don't have a compressor here at my new place yet. It's back in my shop a few hours away. Guess I'll have to just deal with it for now...

The WVO has a separate filter, and is controlled by a solenoid valve. the diesel filter ONLY sees diesel, and the WVO filter only sees WVO, there is no cross-contamination.

so you start and stop engine on straight deezel? does the lift pump do both fuels? or separate system all the way to the inj. pump?

I had similar symptoms once. It turned out that the second fuel filter in my tank was the culprit. The first filter in the tank is the one that's on the bottom of the pickup unit. That one can be removed, cleaned, and reinstalled. The second was INSIDE the pickup unit. I just removed that one completely.

Before dropping the tank, remove/clean the screen on the bottom of the fuel heater assembly. It takes a 17mm socket from under the truck. Only a little fuel will spill. If that's not clogged then I'd look to the pickup unit filters as being next in line to check.

Thank you!


Yes, GreaseCar has a control module in the cab, as shown here:
Attachment 44248

It controls the supply solenoid. That solenoid has 2 inputs (Diesel tank via fuel heater and fuel filter, & WVO tank, via it's own, heated fuel filter) and 1 output (to lift pump). There is a 'Flush' mode, that flushes the system with Diesel for (I have it set for) 30 seconds. That way the lines are cleared.

I have NOT run WVO since the lift pump change.

Sorry in advance for the crappy quality, they were just taken with my junk cell phone...

Dodge OEM setup:
Attachment 44249

GreaseCar setup (My setup)
Attachment 44250

Actual photo of the pump area:
Attachment 44251
Another:
Attachment 44252

I know it looks kinda crazy. I did not install it, and am not very proud of the workmanship, and plan on changing it a little, but hey, it works. (Well- wait... why is this thread here if it "works?!!")


So far, I've checked the following:
-Connections at fuel tank
-Fuel lines from tank to engine bay
-All of my rubber lines associated with the pump/solenoid assy
-Fuel Filter is changed 100 miles ago
-Lift pump 2k ago (never run WVO through it
-Fuel heater pre-filter assy was cleaned, heater removed

Here's what I'm planning to check:
-fuel filter inlet banjo bolt gasket. They had to remove the banjo and attach a Tee (as you can see in the WVO diagram above) and I noticed the gasket has some cracking around it. (no fuel seepage, but that's on the suction side of the pump, so it probably wouldn't show, right? It's just potentially letting air into the lines...)
-do some sort of fluid/pressure check of the lift pump. I know it's new, but who knows, maybe it's a Lemon? any tips on this? or just do it 'per the manual'?
-Fuel tank fuel filter like v8440 pointed out
-streamlining the whacko fuel line situation near the pump and ruling out the rubber hoses/brass barb fitting connections as leaks.


Thanks for all the advice. This is driving me nuts! :dang:
-Andrew

maybe the wvo is/has knocked some crud loose and your injector(s) are slightly clogged? but you have a fairly new (2000 mikes) lift pump, idk. maybe time to switch to an aftermarket fuel system like the fass or airdog or make your own. all your symptoms seem to be pump related. i do know that starving the inj. pump is a quick way to kill it. see if you can rig up a temporary pump system with an electric pump bypassing the lift pump and have the fuel pressure at 16-20 psi? and see if that allieves your symptoms. i'd go with v8840's filter cleanin before anything tho. you could have possibly gotten another bum pump too.

just reread the last part of your last post aboot the banjo bolt and air in the system i dont think would cause you to lose pressure like your saying, it should only cause stuttering symptoms, correct?

Forgive me if I missed it, but where did you get the new LP? I know working at napa probably 30% of FPs we sold came back after install not working at all.

Lift pump was from Shiver Diesel, in Tallahassee, Fl. Pretty well known/respected company.

Upon more research, it looks like Holley Black pumps, or equiv., are a decent pump, and can be had relatively cheaply, around $100 or so... So I may try that. Question is: Should I run the pump inline, pre-lift pump, or just bypass the lift pump all together?

I just thought of something else easy to check: Start the truck, and make sure the shutoff solenoid on the side of the injection pump is pulling the fuel shutoff lever all the way up. If it has gotten weak and is only partially opening it, that would be a dumbass way to have your fuel supply throttled back. You must start the truck first-merely turning the key to the on position will NOT do the trick.

ooo... Good call, easy check/replacement. Let me check that out after work this morning.

x2. I had that WTF problem more than once using a choke cable. :argh:

if you do decide to bypass it altogether, diesel power did the exact mod using a holley pump on their 89' dodge theyre trickin out. make sure its diesel compatable too, if need be.

Had a friend of mine tell me today that it's also possible that the fuel pressure return spring or whatever it's called could be gummed up. In short, he said it's accessible by taking the banjo fitting out and you can see the spring and can clean it out. Also that it is possible to tighten the spring a click or so and get a little more fuel pressure out of the system. What do you guys know about that?

Oh, the overflow valve. I guess that's possible, though I doubt that would cause problems only at high rpm and load. I've never personally messed with mine, but I understand it's not hard to work on. That would be an easy one to find out more on with a search.

Word.

And just to clarify, it seems that it does it at any rpm now, even idle- it fluctuates from 20-10... Happens at 50mph, lockup, low rpm. I think it mostly has to deal with the demand of fuel. The pump seems like it just cannot keep up.

before diving in to a whole new system, maybe get another pump if theyre not to expensive. but it sounds like it would be better to go with a new system anyway

Sorry, I cant remember - have you changed the overflow valve?

Should have got the adjustable one from Torque Tek when you got your snubber.

No, i haven't changed the overflow valve. As for the TT product, i saw them, but I did not know I needed one on a stock system? I thought that was just for boost pumps and complete bypass setups?

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Just ordered an overflow valve from tork tek. Should be in by Friday, and I should hopefully see something improve from it! Boy that would be nice!

Easy fix if thats the problem. Hope you ordered some of the 14mm sealing washers they have.

Yep! Got some of thems too. I sure hope this works! I'm moving Saturday and need to haul my 40' travel trailer. This better work :dang: Lol

Update:

-Pulled off a couple lines to replace (rubber lines). Should have it all put back together tomorrow.
-Pulled out the stock overflow valve and sprayed it with cleaner. Took it out for a drive, it seemed to keep the pressure up a little bit better than before (holds around 20-23psi), but as soon as you touch the throttle and start 'loading' it, it plummets towards Zero!
-As I said, I ordered the new overflow valve from Tork Teknology, and it should be in Tomorrow. It's calibrated to 30-32psi out of the box, which is precisely where the 'sweet spot' is for the stock fuel setup(as per the information from Rob at Tork Tek, on his website and over the phone). That should REALLY help me out.

I still need to make sure that no air is getting into the system. Rob (TT) gave me some good pointers. He suggests that I install a clear tube in the pressure line into the P-pump, so I can actually SEE if there is any bubbles past the lift pump. If so, just start workin' my way backwards making sure everything is sealed up.

IF it still giving me trouble, I will try the following, in this order:

-Bypass all WVO business and run a straight line just like the OEM is set up. Thus ruling out my solenoid as the culprit.
-Pull the heater bowl assy and double check everything (remember, about 2k ago I yanked the actual heater and cleaned the screen.) I might replace the screen instead of just cleaning it this time. as well as the seal.
-Drop the tank and clean that filter.


Am I missing anything? I think I'm covering pretty much ALL of the fuel system in all of these troubleshoots. This is driving me bonkers! Cummins are supposed to be bullet proof!?!?! just a stupid little air leak can bring down the beast. It's the proverbial Achilles Heel to the Diesel. :td:

HAVE YOU FLOW TESTED YOUR LIFT PUMP? ALSO HAVE YOU INSPECTED YOUR CAM LOBE FOR EXCESSIVE WEAR?

No, I haven't. Any pointers?
Assuming you can simply run the pressure line to a cup and watch the CC's but I need some more info. Or should I take it off and take it somewhere?

Think I found the problem...

After setting this up:
Attachment 44187

I noticed some bubbles flying through the lines...

And when I stopped the engine, they pooled up so I could see it clearly:
Attachment 44188

Now to just follow everything back and double check everything. What a pain! But I highly recommend doing this, as it made it very easy to diagnose. I should I have done this the first week I was having troubles... hind-sight is always 20/20.

so youre sucking air up from..?

Don't know yet. Today the plan is to check the fuel filter and heater bowl assy. Also, bypassing all WVO related lines. Mainly that just means installing the short bent line from the bowl to the pump.

Weird that it would just all of a sudden start leaking, ya know? It must be something that I recently touched, like tHe filter. That's all I can think of! Everything else is clean...

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Finally found the problem!

Fuel strainer screen in the heater bowl. Took it out and cleaned it as best I could (WVO is some nasty stuff... it had it mostly clogged up, and YES i cleaned it 2000 miles ago. I think my WVO filter is worn out.) and put it back in. Fuel pressure was idling around 25-30psi. went down the road, floored it to 35psi of boost, didn't drop under 10-15 psi! (stayed closer to 20).

And best of all, NO bubbles after I went out for a drive and shut it down. just solid diesel in the clear tube. I highly recommend making one. Makes troubleshooting quick and painless. I put the regular hose back on the feed line and threw it in the tool box. I'll use that puppy again someday i'm sure.

Looking forward to the new overflow valve (hopefully arrives today!) and I will probably just bypass the strainer for now until I can just get a new screen ordered. I just won't run any WVO till then. Shouldn't have any troubles.


Thank you for all of the advice!

Sounds like you're about to conquer it. Clear lines-that's a neat idea. I wonder if I can find clear lines that will withstand diesel in an appropriate size to redo my truck when the time comes?

That did it! Pulled the 12k trailer about 50 miles with a few big hills in the route. Fuel pressure never went under 15psi under full load, then stepping on it. I need to buy a new screen, as I believe that is why it's still pretty low, pressure wise. Not loaded it can keep up and pressureize the system to around 30psi, exactly as Tork Teknology claimed. What great products! Highly pleased with them... Spread the word!

Again, thanks for all of the advice, guys. I love this site!

so it was just the little screen on the in the heater? wow thats cool. good to here you got that pig up and running. are you ditching the wvo setup or keeping it? at least you know where to start next time, huh?

Exactly!

Keeping the WVO, but will take my filtration process more seriously from now on. I might bypass the screen all together and just rely on my filter(s) to do the work, and just change them out more regularly...