T444E low fuel pressure, loss of power

[aawil]

I have a 95 International 4700 flatbed with a T444E, today loaded I was running along at 55. Started loosing power and slowly dropped to 45 MPH on flat ground with my foot on the floor. Shifted down, and started picking up speed and then it ran fine the rest of the 5 miles home. I had this problem about a year ago and pulled the fuel pressure regulator apart and cleaned it, and blew air back to the fuel tank in both the supply and return lines. It has ran fine since then until today. I did that again as well as cleaning the rock screen on the fuel bowl. Checked fuel pressure at idle I have 50 psi, Wide Open in Neutral it drops to 35-40 then picks up to about 52 then bounces around between 40-50. Pump getting weak? Thanks

 

[BamaBus]

I don't have an answer but I read this thread and remember post #3 from cadillackid about a spring. ?? https://www.skoolie.net/forums/f37/t444e-fuel-bowl-depete-44374.html#post517295

 

[aawil]

I believe he’s referring to the spring in the fuel pressure regulator, which is in the return circuit. I have read about a different spring in the past to increase pressure. Could be something to do, I just don’t remember the gauge bouncing around so much when I had this problem before. The way it drops down then comes back, makes me think there’s something causing it to drop before coming back.

 

[Omnibot2000]

Could be almost anything. I worked on a kabota tractor recently. Would run great for 15 min. Then loose power and barely move.

Shut it off, open hood. Look at the thing and scratch your head. Close hood, start engine, lots of power for 15 min. then loose power.....rinse and repeat.

Issue was......grass in the fuel tank and slowly clog the pick up when running.

If you have a drain on your tank, drain it. Look in with a light or scope to see if it has something in it and transfer the fuel back in the tank after cleaned.

Does not cost much and rules it out.

 

[Kentucky Dreaming]

I had a Ford lawn tractor almost 40 years ago with a Kohler engine. Same deal. when it got warmed up it would act lean and die. Had grass clogging the carburetor. That was a really dry summer.

 

[Kentucky Dreaming]

This scope has come in handy for me:

https://www.amazon.com/dp/B0791DG4FK?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

Easy wi-fi connection to any sillyfone.

 

[aawil]

Probably would be wise to drop the tank and check the pickup tube/strainer. Don’t know exactly what it has, guy down the road had a tractor last summer that was running poorly he had alge floating around the pickup. Would have been nice if I hadn’t just filled the tank.

 

[Omnibot2000]

Probably would be wise to drop the tank and check the pickup tube/strainer. Don’t know exactly what it has, guy down the road had a tractor last summer that was running poorly he had alge floating around the pickup. Would have been nice if I hadn’t just filled the tank.

I don't believe these tanks have a strainer and it is wise to back blow with air back into tank to clear blockage.Does not sound like a cracked pick up to me.

He could also go through the fuel sending unit after he robes it for further access.

 

[cadillackid]

if i had to guess on this one id say the system is somehow sucking air.. the regulator could be sticking but id expect to see it also bounce way over pressure at times too if this was the case..


the regulator spring change was a dealer TSB to help rectify the "idle knock" often heard at slow idle in many pre-2000 444E.. they surmised the fuel rail pressure around cylinders 6 and 8 was dropping too low to give the #8 injector a good fuel charge as it fires right after 6 (next door)... so they increased rail pressure with the new spring..


bouncing between 47-50 or so was the original spring in mine.. im thinking in your case the spring wouldnt help much as it seems like you are fuel starving.. its possible the stock pump is giving up the ghost too.. although it seems usually when they die they leak..

 

[aawil]

Still thinking I’d have to drop the tank to gain access through the sending unit , tank is under the passenger door. I did blow air back to the tank on both the supply and return lines and there didn’t seem to be an obstruction that was blown loose. Fuel pump doesn’t appear to be leaking, maybe the short rubber lines on the fuel bowl could be getting old and allowing air in? I’ve seen that before on braded fuel lines.

 

[aawil]

Today it ran good empty but loaded would intermittently loose power again. See fuel around the pump in the valley now. Thinking the fuel pump is probably the logical thing to replace, don’t see any leaking lines. Looks like the turbo needs removed to get the banjo bolt out?

 

[Omnibot2000]

Today it ran good empty but loaded would intermittently loose power again. See fuel around the pump in the valley now. Thinking the fuel pump is probably the logical thing to replace, don’t see any leaking lines. Looks like the turbo needs removed to get the banjo bolt out?

I just changed mine a few months ago. You can do it without removing the turbo. Just a little tight.

That large banjo bolt once cracked is generally easy to spin off.

I think I had also used a stubby wrench as well.

Change all those little fuel lines as well. They may still be original. All mine were cracking.

 

[aawil]

Installed the new pump and changed the rubber fuel lines from the fuel bowl to pump. Also decided to drop the tank, there is no screen on the pickup just a tube. I had a few chunks of rusty goo floating around the bottom of the tank. Maybe that was the problem. I have rinsed the tank out with water and was going to dry and put it back in. Is there something else I should do for the sludge? Also, my fuel sender float has fuel in it, gauge was still working. Both part stores I’ve called said they can’t get one to call the dealer, anyone know anything about getting one elsewhere? Tank is a 50 gallon Snyder mounted below the passenger door.

 

[Omnibot2000]

Installed the new pump and changed the rubber fuel lines from the fuel bowl to pump. Also decided to drop the tank, there is no screen on the pickup just a tube. I had a few chunks of rusty goo floating around the bottom of the tank. Maybe that was the problem. I have rinsed the tank out with water and was going to dry and put it back in. Is there something else I should do for the sludge? Also, my fuel sender float has fuel in it, gauge was still working. Both part stores I’ve called said they can’t get one to call the dealer, anyone know anything about getting one elsewhere? Tank is a 50 gallon Snyder mounted below the passenger door.

If you have sludge in the tank.......if you can pressure wash with hot water. If no hot water pressure washer, I have used a cup of Mr.Clean and pressure wash with cold water. Rinse out really good.

If the float is metal. I know people with carburetors would use soldier and a torch to seal them back up.

You could try calling the dealer. Might be cheap enough that it would not be worth your time.

 

[cadillackid]

I know I bought sending units onlne for both of my 3800's .. was trying to find the orders, it was like 8 years ago but they werent dealer OEM and they still work OK, I had the same issue float was full of fuel and also the resistamce wiper wasnt smooth.. when I manually operated the float the gauge jumper all over so I replaced them.
the tank depth is the only thing that matters and you can bend the float bar int oa shape to get the geometry you desire.. I set mine so when they read E there is still a couple inches of fuel left so im never atempting to suck the last little bit of possibly dirty fuel off the bottom

 

[aawil]

It wasn’t built up all over the tank like I’ve seen in pictures, just a few chunks. Bottom of the pickup tube was slimy, I rinsed it with cold water, cold water pressure washer then a rinse with hot water. Looks like I got it clean. Sending unit float is plastic. I’ve seen Power Services Clear-Diesel at the local NAPA, maybe treat with that when I refill with fuel?

 

[Omnibot2000]

Run that clear diesel and maybe even check and replace all your fuel filters.

Really sounds like you got a case of Algae.....which it truly is not Algae but that's a different conversation.

 

[aawil]

I’ll do that, also have a new fuel filter this just has the rock screen and the one in the fuel bowl.

 

[cadillackid]

Run that clear diesel and maybe even check and replace all your fuel filters.

Really sounds like you got a case of Algae.....which it truly is not Algae but that's a different conversation.

ive always wondered what it was.. ive seen the nastiness of old fuel many times being involved with rescuing old busses that have sat for years.. but always wondered how algae could "grow" in oil.. I consider diesel fuel more oil than anything..

 

[BamaBus]

ive always wondered what it was.. ive seen the nastiness of old fuel many times being involved with rescuing old busses that have sat for years.. but always wondered how algae could "grow" in oil.. I consider diesel fuel more oil than anything..

I wish someone could post a good fuel polishing set up like in the marine world, part numbers and all. I can't seem to get a complete detailed plan anywhere.

I would like it to be portable where the pump power supply could be either electric or fuel based. I personally would chose an electric pump for my situation.