p 1211 code

[sgt dave]

i've been getting a random p1211 code in my truck for the past two months. i've been monitoring icp pressure and duty cycle and i havent noticed anything that would cause the code to come up, so i dont think its my hpop. the truck has been set up like my signature says for two years. never had a problem before. any input is appreciated, thanks.

[BigFuel]

Oil clean and full? How does the truck idle/run? When was the last fuel filter swap? How does the IPR look? Clean with the brass "nut" on the back tight? No leaks in the motor valley? If it is running a little rough does it run better if you disconnect the [EDIT]ICP? What is fuel pressure at idle/cruising/WOT?

[Patrick Feeley]

Originally Posted by BigFuel

If it is running a little rough does it run better if you disconnect the IPR?

Did you mean ICP vice IPR? Normally the engine will die if the IPR is disconnected (if ICP is disconnected, it should run off default table values and set a code, but still run). Cheers!

[BigFuel]

^Yes I get them backward sometimes. Sorry.

[Patrick Feeley]

From the HPOP guide:

P1211 sets if ICP is 410 psi above or 280 psi below the desired pressure for 7.5 seconds.

ICP more than 410 psi above command for at least 7.5 seconds can set a P1211 code. IPR with low duty cycle (less than 8% @ idle) and engine running, indicates a restriction in the drain circuit. This restriction is taking the place of the IPR valve, driving the IPR duty cycle lower, with higher than expected ICP. The excess restriction will be in the reservoir, front cover, stuck IPR valve, or debris above the edge filter. The drain path through the reservoir and front cover can be visually verified. Typically the pump or IPR
must be replaced to repair this concern. Do not replace both components at the same time.

This often occurs after the oil pan is resealed where excess sealant is forced through the lube system (short circuit check valve) and trapped at the edge filter of the high pressure pump.

Cheers!

[sgt dave]

figured out the problem. my pump blew up last week, so its on its way back to bob riley for a rebuild.