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.