Yesterday while attempting to leave town, I noticed my rail pressure wasn't over 10k and wouldn't get over 10k with very un-steady readings. I goosed it harder and the BHT3B stalled....

Immediately pulled over, pulled Dr. Performance box. Cranked it back up. Everything seemed fine and i was in hurry, so i kept on. I noticed at cruising speeds that rail pressure was low and dropped even lower under power. Power was still there and seemed good at WOT, but cruising pressures seemed low. I'm talk 5-8k at 70mph, roll into the throttle and RP drops to 3-4k before ramping back up around 10k.

Drove 300+ miles today. RP was un-stable and comparably low. The closer I got back to home, the lower the pressure got. Seemed it was taking more throttle input to hold speeds. Parked it, had a diesel get together, 3 hours later I get back in to drive home. Pressure seems OK now but not as high as it has been.

Seems that when its hot, pressure doesn't behave correctly. And trust me there is plenty of heat under my hood with twins. Keep in mind I limped around for a week with no lift pump in the past.

OK....what are my possibilities?

1) Relief Valve heading south?

2) CP3 getting tired?

3) YOUR IDEAS HERE.

Gotta be back on the road Sunday morning for another 200+ mile trip, then turn around and drive 100 miles to meet the John Deere mechanic to fix the tractor I broke last night. NEED a quick solution and praying its low cost!

 

Oil level ok? Poss Stuck/Seized injector. FCA poss stuck also or like you suggested blown relief valve.

 

DiProcal gauge? If so, it's probably the gauge. That sounds very similar to what mine was doing. I sent it back and the new one seems to be fine.

 

Try unplugging whatever gauge is taking your RP reading. I don't know what it is, but mine can run bad with the gauge on, then take it off and everything's great.

 

Yes im running a DiPricol Rail gauge. You can hear the rail pressure as it moves up and down and i can also see it on the gauge.

Im gonna check the relief valve today....as well as oil level. I'll unplug the gauge and see how it goes.

I could also go to the dealer. They can do a test on each injector with the truck running.

 

Your RV may be toast...if the gauge does not return back to "Normal" operation after a few key cycles...it is not the gauge...IMHO.

You have played with pressure...and a bit too much a few times...I did the same thing!

Get a new one...or cap it just to test. It may also explain your hot temps...
poor spool...irratic truck behavior with different mods...etc.

Those RV's are sure a pain!

 

Whats the easiest way to cap it?

 

just weld it! or slap some duct tape on it

brett

 

haha brett you make me laugh but i think i'll take the non-king of the hill solution

 

A high grade bolt...

 

All i have to do is get a good bolt and replace this one?





Notice the black stuff.....its obviously soaked in diesel too and my truck has been sitting for 15+ hours.

 

Mack bolt and steel will most likley have the bolt, they are right across the road from me. I am pretty sure it is a 12mm 1.5 thread you will need.

tel# 778-8088

 

Yep...use the sealing washer's though...

 

I've got an 06 relief valve on my truck now. We'll see how it goes.

 

You've got the entire relief valve or just that banjo bolt??