LLY Oil/PSI Non exhistent
 

2006 LLY in a Top-Kick 5500. Had a very dirty tank of fuel run through it. Plugged the fuel filter almost solid. Shortly after won't start. Oil PSI seemed high when we bought this truck so we changed the sender with no difference, and now it fluctuates from 0-200 kPa. Really need this out of the shop, I am tired of looking at it.....

Would the inconsistent oil psi cause the low fuel psi? Truck is calling for 42mPa and the best I was able to see was 12 after I bled an injector. Now it is back to 2-6..... Pressurized the tank to determine if there was a plugged line, nothing is evident...

Should I be ordering a new CP3 andan oil pump?? We are a construction company and I can't allow this truck to be a shop lizard....

Should add that the truck ran fine after fuel filter change. Ran about 2 tanks of fuel through it before it started to get progressively worse.

Check oil press actual vs. displayed with a scan tool, you can go into the ipc data to view this. More than likely its just a bad cluster and not an oil press. prob. You can check the pump output and injector bal. rates with a scan tool to determine fuel problem. 2006 should be an lbz but, that doesn't make any diff.

I'm presently hooked to a Tech 2. The oil pressure was confirmed against the tech 2 and then when it was stuck at 0 psi I added a mechanical gauge to confirm. After removing the mechanical to put back to stock as I was certain that it wasn't a bad sender, it shows 29 psi while cranking.. Injector balance rates are at 0. Fuel PSI at rail is only 2-6 mPa (250-850 psi). Gauge on the return line shows 1.5 psi.

I believe that since it's a top-kick and not a passenger vehicle is the reason for the carry over of the LLY. Tech 2 ID's it as a LLY. I personally don't know or care what the difference is, I simply know that this machine doesn't run, and needs to......

So oil press is ok then? I overlooked where you said truck is no start. bal. rates wont read if not running. You can check inj. return rates manually, also check for rail relief valve bleeding off. You can also do a pump out put test manually.

I can't be certain as I don't know enough about these trucks, but the "actual" fr pressure remains at 2 mpa after engine cranks. Does this need to be higher or is relief valve nfg?

it should be 1.8 - 2 key on engine off. It should build to desired while cranking unless you have low or no pump out put, an injector messed up or relief valve stuck open. There is a rubber hose at the back of the driver fuel rail that connects to the fuel return plumbing. Crimp it and look for change or disconnect it from rail and see if fuel is coming out of the nipple on the high press rail.