Slow pulling a hill

[smgman]

Well I am not sure if my motor has had it or not . I have a 72 Am General Duece with the LDT-465-d (think the D is the Whistler) . The truck seems to run smooth and have okay power on level ground however when I try to pull any real hill on the rd it has trouble and I find myself down shifting to 3rd with the truck at 2000 rpm and maybe 20 mph if I up shift the rpms drop and the truck will loose all power. I have noticed this is not just large hills even a small hill on a st will result in downshifting . Seems it has very little power to pull a hill . When I down shift and get the RPMs up seems like I should be able to shift up to the next gear and continue to build speed but she falls on her face .

She has around 54000 miles and does not seem to smoke anymore then any other duece I have seen . I drove it home on the Highway and was up to 60 MPH no problem on flat ground .

I changed the Oil and fuel filters as well as the Oil about 6 months ago . The Oil pressure seems to run low just above maybe 5 at a Idle and up too 30 at 1500 or more RPMs .

As far as I know the truck is stock and I do not see a rebuild tag on the motor however the truck has a few tags showing replacment hard top roof and electric wiper motor back in 2003. I would like to get her running strong as she is a clean duece with a clean body , Hard top roof , Cab Heater, Winch , great tires , cargo cover and bows included as well as the electric windshield wiper upgrade and I payed $2500 2 years ago .

My hope is Maybe a bad pressure gauge and needs Injector pump turned up ?
My fear is bad motor that needs replacement or rebuild .

Better to rebuild these motors or replace them ?


Like most people I am on a limited budget .

Sorry for the long post guys I am trying to paint the whole picture and then get suggestions

Thanks Guys for all the info on this forum .

Jay

 

[Jinx]

I can't get my truck up to 60mph. You must have oversized tires or are pushing your truck too hard.

Also all deuces slow down on hills. It's a 135HP engine pulling a 13,000lb truck.

 

[Barrman]

Somewhere in one of the many manuals I have for the M35 it says something about loading the truck up to max gross weight, driving it hard on fresh fuel for 100 miles and then see if the problem is still present.

I would suggest that for you as well. I know my truck looses umph when I just run it around empty. A good example is a few months ago. I drove 120 miles empty to pick up another M35. I hooked up the tow bar and started home. 45-50 was all it would pull on the flat and down to 35-40 in the hills leaving San Antonio driving I-10. 100 miles later and I was having to back out of the throttle pulling steeper longer hills to keep it below 50 up hill.

Drive it so it works and it will be happy.

Of course, as pointed out already. Make sure all 3 fuel filters are clean, air filter is good and your brakes aren't dragging.

 

[cornrichard]

One of my trucks shows 15 lbs pressure at idle and 30 running. It has not given me any trouble yet. A common problem with these trucks is a mismatch between the oil pressure sender and the gauge. This will cause your oil pressure to show 1/2 actual pressure. I agree with the other posts when it comes to running the truck. I get a lot better performance after about 20 minutes on the road at speed. Anything over 5 or 6 percent grade is going to slow you down if there is any considerable distance.

 

[Wildchild467]

Make sure your engine is up to temperature too. if its cold out, a winter front cover isnt a bad idea in my opinion. In the late fall i found that when i put the cover on, it ran better because it allowed the engine to get up to 200 degrees vs the usual 180. without the cover it would only get to 180... not bad when its warmer out but when its cold, i dont think it has as good of combustion. thats just my experience though. I wouldnt let it get hotter than 210 though, dont want to cook it or blow a head gasket.

 

[Ridgerunner]

10-psi of oil pressure for every 1000 rpm you spin the engine, would be considered safe.

 

[nk14zp]

Change your fuel filters.

 

[gimpyrobb]

Grab a mechanical gauge and screw it into where the sending unit is. Verify your oil pressure. Next, turn the fuel up. Since you are on a budget, I'll assume you will not be using a pyro, so bump the fuel up SLOW. I'd start with 3-4 flats of the nut at the most. Keep increasing till you are happy.If you get it so there is just the SMALLEST bit of smoke at idle, you are done till you get a pyro.

 

[91W350]

I do not run mine nearly as fast as some of these guys do. Usually around 48 mph tops, normally around 42 mph at 2,000. It pulled all of the hills coming home from Ellsworth AFB in the high side of 5th. I thought coming out of the Missouri River Valley on I-90 we were going to have to drop a gear, but around 1600 it crested, happily purring along. Since home I have run around about 1,200 miles and it seems to have plenty of pull for our area hills, even when I went cruising through the Flint Hills last week. I have no idea if my pump is set high or not. It usually runs around 55 lbs oil pressure on the road and 45 at a warm idle. But who knows, I may have a bad sending unit or mismatched one. I need to lay off pleasure driving, my fuel fund is taking a pounding. Glen

 

[91W350]

Grab a mechanical gauge and screw it into where the sending unit is. Verify your oil pressure. Next, turn the fuel up. Since you are on a budget, I'll assume you will not be using a pyro, so bump the fuel up SLOW. I'd start with 3-4 flats of the nut at the most. Keep increasing till you are happy.If you get it so there is just the SMALLEST bit of smoke at idle, you are done till you get a pyro.

Yeow! Mine smokes quite a bit at idle, maybe I better invest in a pyrometer. What is a good target exhaust temperature on the Multifuel? My old Dodge usually runs around 750 to 900 on a really hard pull, otherwise it seldom goes over 600.

 

[gimpyrobb]

My truck runs on flats around 900 and I have no problem running it right at 1200 on hills.

 

[91W350]

Thanks Gimpy, where did you tap into the exhaust at? Glen

 

[Stretch44875]

If that is your truck in the avatar blowing smoke, then your pump is cranked. Mine is cranked up and I don't think it blows as much.

 

[gimpyrobb]

I tapped in the manifold just above the turbo. If you use the same spot, there is a divider in there, don't try to go in the very center. Bjorn(cranetruck) has posted pics on where he tapped his, I went off his pic.

 

[smgman]

I understand the trucks do not pull hills at 40-50 MPH but I was thinking 15-20 in 3rd gear at 2000 rpm was a bit slow and why is it if I shift up to 4th she is dead and can not build any rpms at all . As for the Highway speed I stand corrected I picked the truck up and drove it 40 miles home all flat highway and she was running around 55 and I was not down hard on the pedal .

My buddy was behind me with his deuce he had purchased the same day he was running around 50 mph his was not a turbo .

I have replaced all 3 fuel filters and the oil filters as well as the Oil . My truck seems to smoke a little at Idle and I get a good puff of smoke when I give it some throttle . SO I will need a Pyrometer before turning up the Fuel . As for being on a budget I don't mind buying a pyrometer but my budget can not afford a new motor at this time .

Will try Mechanical Oil Pressure Gauge and a Pyrometer then turn up the fuel if Temp allows.

Maybe I need to get one of my Local MV collectors to stop over and drive her so they can tell me if I am expecting more then the deuce will perform or not.

I think I put some additives in the junk low sulfur diesel but need to check that as well . I would imagine these trucks run better on the regular diesel



No looking for a race truck by any means but I would like to be able to pull a average hill on a rd at 30-35 MPH . 15-20 is a bit slow .


Thanks for the help everyone .

 

[91W350]

If that is your truck in the avatar blowing smoke, then your pump is cranked. Mine is cranked up and I don't think it blows as much.

That is it, on one of the steeper hills in our area, Coronado Heights. I just rolled slowly until I had a good straight shot at the camera guy. I think it was around 1500 rpm and climbing. There was almost no breeze, so the smoke was hanging pretty good. It does smoke a lot though, much more than any of the rest of my diesels have.

So you tap in pre-turbo? I thought we always aimed for as close to the exhaust side of the turbo as possible. That would also explain a lot of the temp drop on my Dodge.

Glen

 

[Barrman]

If your complaint is the 3rd to 4th shift. Then you are like all the rest of us. The problem is that a gear is missing. The Gasser M35 trucks used the same transmission. What is 4th on the Multifuel is actually the 1:1 5th gear from the Gassers. When the multifuel came along with less rpm range. 4th gear from the transmission was removed and the current overdrive 5th gear set installed. That is the reason for the funky shift pattern.

You can live with it, drive in low range to 5th, pull into hi range and shift to 4th and then go to hi 5th. That makes the jump smaller and with a load, gets you going without any kind of big stress on the engine.

Glenn, are you running straight diesel?

 

[cornrichard]

Just another idea. You might check your air filter and mushroom. You may have picked up something that is giving you an air restriction. That will make it smoke at stock fuel setting.

 

[dittle]

A question comes to mind when you say smoking at idle? Are you letting it sit at idle for a long time and then rev it up causing smoke? If so then I would call it normal...part of the multi-fuel engine design (wet cylinders I believe is a term I've heard before). I've bypassed my FDC but did not change any fuel settings. At idle my exhaust is clear to very very slight haze. If I let it sit for a while at idle and rev it I get smoke as expected. That being said I have no issues holding a lot of hills at 50 - 54 mph but I do back off based on my boost gauge as needed. I will also get some smoke when shifting gears but once running down the interstate my exhaust stays clear as the turbo is already wound up.

 

[big1096]

I usually keep my truck right around 45-50 on the open road, and that's right around 2000-2200 rpm in 5th. I don't usually lose speed on gradual hills, but I do have to shift to 4th on steeper grades. I have to go to 3rd on really good hills, and that's right around 20-25 mph, at right around 2000 rpm. But it feels about right to me.