Manual power increase?

[d90boy]

I was at the local dealership talking to my tech buddy who has been to the school for the new motors. He mentioned an overflow or return valve of some sort on the fuel rail that had some sort of cap on it. Under the cap was a hex or something that could be adjusted to manually increase pressure in the rail for a power increase. Anyone have any idea what he's talking about? Since I don't have access to a truck I couldn't look for it. Any ideas?

 

[sag2]

You can't increase the pressure in the rail. There is a pressure sensor in the rail that sends info to the ECM. The ECM in turn directs the pump to raise or lower pressure based on engine requirements.

In class however, we did command full pressure for a test, and it really started to knock. Also if you loose the pressure sensor signal the engine is de-rated and you can not exceed a pre-determined RPM.

 

[d90boy]

Thanks for clearing that up.

 

[MCummings]

Originally posted by sag2

... we did command full pressure for a test, and it really started to knock. Also if you loose the pressure sensor signal the engine is de-rated and you can not exceed a pre-determined RPM.

Check out this thread,, Can an ISBe sound like an ISB... .

 

[Vaughn MacKenzie]

Popoff valve

I am going to guess the adjustment is the safety or popoff valve in the event there is a problem with the pressure sensor. Otherwise I'm sure the pressure would rise uncontrolled and do untold damage, not to mention potential personaly injury/death. Best advice? Don't mess with it



Vaughn