Dodge Cummins Diesel Forum banner
  • Hey everyone! Enter your ride HERE to be a part of October's Cummins of the Month Challenge!
1 - 20 of 20 Posts

·
Registered
Joined
·
94 Posts
Discussion Starter · #1 ·
So, I had a lift pump go bad. So while I was at it, I added A TorqTech Overflow valve, stainless lines, new rubber line, new fuel filter, fuel pressure gauge, and, of course, the lift pump. I bled the system, and the first 3 injectors. fired right up!! so been driving it without problems. Today, I was hauling my Kubota, and it had no power. cut wood, loaded it up, and headed for home. Now it had all the power like normal. Nothing is turned up on the truck, as I haven't beefed up the trans. It did this same thing the other day.
Any ideas? I read possibly the AFC. I would like to know some checks I can do to narrow it down.
I hooked the fuel gauge to the banjo fitting on the bottom of the pump. Is the correct place to put it for accuracy? I am seeing readings of 45 psi at idle, and 25-30 psi under load.

Any input?
 

·
Registered
Joined
·
133 Posts
sounds to me like your OFV may be out of adjustment. i think the readings your seeing are pretty high.. anyone else?
 

·
Registered
Joined
·
94 Posts
Discussion Starter · #3 ·
Could be. The OFV said it was preset for the factory 35 PSI. I am seeing a lot of people putting a T in the fuel return line, and pulling fuel pressure from there. I hooked mine in where they said to on the paperwork from LarryB's, which was the bottom of the pump. Should I move the tie in to the return line for an accurate reading?

You ever had an issue with fuel gelling up? Its cold in Ohio, obviously, as it is everywhere else. It was 0 in the morning, and the truck ran like crap, and warmed up to about 36* in the afternoon when the truck ran fine. I have never experienced the fuel gelling. possibility?

Thanks for the help in advance. I try not to post on here. I just try to read through everyone else's problem posts and figure my problem out. Vs ask the same ? over and over, as I get tired of reading them over and over myself!
 

·
Registered
Joined
·
541 Posts
You didn't say if you have auto or manual.

If it's auto, check it out if it was in limp mode when it feel like down on power. In limp more the trans will stay in 3rd.
 

·
Registered
Joined
·
94 Posts
Discussion Starter · #5 ·
its an auto, and when I tow, I always take it out of overdrive. I started out in 1st, then shifted to 2nd, and it was a complete dog in both gears. It would barely pick up speed on a flat surface!
 

·
Registered
Joined
·
90 Posts
fuel pressure should be 20psi at idle and no less than 10 at WOT under load. Ive ran blended fuel with no additives at -15 without gelling but its possible i guess
 

·
Registered
Joined
·
541 Posts
Yuup, if you feel like you have no power loss at speed, chances are your trans was in limp mode. It usually go away by turn off and restart the ignition, but if something really went wrong it'll stay in limp mode until fixed. Usually governor solenoid and transducer will fix it but a bit expensive.

When my truck's trans was stock, I couldn't really feel it shifts 1-2-3 so I can probably see why you didn't noticed it was in limp mode right away as you probably can't really feel the shifting when it working properly anyway.
 

·
Registered
Joined
·
541 Posts
I missed the part that yours a 95 so it's a 47RH! I'm more familiar with 47RE. Yes it can be in limp mode if it's mechanical governor malfunctions. For that type mechanical governor, make sure it's weight can sweep in/out freely and no debris or loose valving to let excess pressure to flow through which will make it to be in too high gear.
 

·
Registered
Joined
·
90 Posts
Never heard of anyone going into limp mode with any 47's so it must not be too common, usually they just break...haha
 

·
Registered
Joined
·
55 Posts
Did you change the Pre filter gasket and the diesel Heater gasket?
 

·
Registered
Joined
·
94 Posts
Discussion Starter · #12 ·
never thought of changing or cleaning the pre heater screen. How often should this be done? Anyone had problem with their screens?

Not to sound dumb, but I have never heard of limp mode, and can this happen to a hydraulic shifted trans? my understanding was that the RH overdrive was the only electronic shifted solenoid. couldn't imagine this being sent to limp mode in 1st gear on a RH!?
 

·
Registered
Joined
·
55 Posts
Limp mode is like 30-40% Power of the vehicle to get you where you have to go and not self destruct when there is an issue.

On the RH it can't happen.

Its totally up to you but me and a lot of others have deleted the Pre filter and Diesel heater. Some think aginst it but to each is own.
I deleted mine because I was losing power and the truck would die on me going down the road. From sucking air in the system.
 

·
Registered
Joined
·
1,244 Posts
You could try a 5spd swap...
 

·
Premium Member
Joined
·
16,203 Posts
What's your fuel pressure when the power drops?
 

·
Registered
Joined
·
94 Posts
Discussion Starter · #16 ·
my fuel pressure is right at 28 when I'm driving with no power. Mind you, I bought the Tork Tek fuel snubber and installed it on the bottom of the pump. I just reread the instructions to make sure I read the installation right. Again, at idle, I am seeing 50-60 psi, and 28 under load when running with no power and full power. This is what Tork Tek says a normal Lift pump will produce. But I noticed some are installing the gauge on the return line, and saying they should see a 35 psi, which is what the OFV is set at. Think this could be an issue?

Can I get an accurate reading of what the OFV is doing with my gauge mounted on the pump? The OFV is adjustable, also from Tork Tek.

I plan on doing the preheater delete tonight. can I buy a new upper gasket for this at a local parts store? might as well put a new gasket on it!
 

·
Premium Member
Joined
·
16,203 Posts
On the return line the pressure should be zero to 10 psi max, not the place to connect the gauge.
It should be connected to the spot where the brass needle valve is connected below.

 

·
Registered
Joined
·
94 Posts
Discussion Starter · #18 ·
ok. That's where it is mounted. What is your typical readings? Do mine seem high?
 

·
Premium Member
Joined
·
16,203 Posts
I read about 22 at idle and 30-35 at 2000 rpm.
Cummins' pressure specs are 17-22 psi at idle, 25-35 at 2500 rpm no load
 

·
Registered
Joined
·
94 Posts
Discussion Starter · #20 ·
Wow! mine are way off! How can I adjust these? Will it hurt anything running at this higher pressure? The psi I have tells me I am probably not seeing a leak at the preheater.
 
1 - 20 of 20 Posts
Top