1st time towing - Lackluster performance.

[BigRigTech]

Towed with my 91 for the 1st time today - about 5000+lbs between the 301 CAT and the trailer - not overly impressed with the power.....It didn't feel right to me. The more throttle I gave it the less power I seemed to have. It was blowing a good stream of black smoke at WOT up a long grade according to my f-inlaw who was following me. but it just seemed off to me....Maybe a poor lift pump or plugged IP screen???....The Baldwin fuel filter has about 3500km on it, been on there for 3 months or so. I wonder if my IP timing is off a little - I really see the need to check it now.

The old rig has a 3-4 trips to the quarry to haul 8-10 ton of gravel in the morning so it will be working hard this weekend.

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[FordGuy100]

Here is what I think about the throttle. I'm thinking that when your going up a long grade with a load, and you go WOT, your pump advances the timing, but since you have a big load on, your truck wont gain any more rpm's. So when you go WOT just try backing out of it a skosh until it feels like you have the most power. And FYI my truck will do it to going up a grade with a load, so no fears.

 

[BigRigTech]

I only went to WOT for a few seconds and backed it down a little looking for the sweet spot but never really found it. Once I have some time I'm going to check my pump timing and see if I can "sharpen" it up a little. It is a very long grade and you start from dead stop at the lights...I wasn't holding up traffic but the old girl was rolling along about 60-70km/h and a little over 2600rpm for a bit....Once I got up on the level to 60mph it was fine from then on. The truck tows really well, handles nice and rides 1/2 decent too.

 

[Mr_Roboto]

Here is what I think about the throttle. I'm thinking that when your going up a long grade with a load, and you go WOT, your pump advances the timing, but since you have a big load on, your truck wont gain any more rpm's. So when you go WOT just try backing out of it a skosh until it feels like you have the most power. And FYI my truck will do it to going up a grade with a load, so no fears.

Timing advances with RPM and retards with throttle. So at low RPM and WOT timing is retarded.

With a heavy load you need to downshift. When I drove semi trucks we would pull grades with the motor at the governor.

 

[BigRigTech]

I was in 2nd gear for some of it and 3rd for the rest. I had the OD shutoff until I got to the level grade. My rig usually runs about 2600rpm at 60mph in 3rd. to run 2600-2700rpm at 70Km/h I would have been in 2nd gear.

 

[towcat]

BRT-
these trucks aren't noted for barnburning performance when there is no turbo hooked up to them. They'll get you there slowly, but you'll get there.

 

[RLDSL]

I was in 2nd gear for some of it and 3rd for the rest. I had the OD shutoff until I got to the level grade. My rig usually runs about 2600rpm at 60mph in 3rd. to run 2600-2700rpm at 70Km/h I would have been in 2nd gear.

There's the problem. Before I got a turbo on mine, it took a while to find out how much the thing liked to wind up ( especially since I used to take care of a fleet of busses with these engines in them ,that were all governed down to about 2800 and thought I was screaming the thing) Once I found that it would pull nicely at 3000+ , no more hill problems. Wind that puppy up and go

------Robert

 

[BigRigTech]

I did wind it to 3k for a bit but with 410,000km on the clock I can't work the old girl too hard, I need it to last.......It is a VERY long grade and it was starting to get pretty warm when I got to the top. I haven't got any actual guages yet but it was the highest I've seen it go on the stock gauge. I'm waiting for the triple gauge dash pod that I bought on ebay to show up so I can install some....Like I said above, it was the 1st pull with it and I have to find the sweet spot on the throttle - all vehicles have one. My 96 F150 4x4 was the same when I had 1.5 tons of gravel in the box.

 

[Exekiel69]

Mine loves 4th gear at 60mph, I smoked other new and not so new brands with that combination towing and empty, this engines do respond but as You said You need to find a sweet spot.

 

[BigRigTech]

Not sure what to think on the power issue, I hauled 4 loads from the quarry this morning, 2+ metric tons in each load and the 7.3 hauled them for a joke compared to that friggin trailer and excavator....The old man is out there jacking up the trailer right now to see if it has a wheel dragging or something...

 

[sign_man]

It was blowing a good stream of black smoke at WOT up a long grade according to my f-inlaw who was following me.

IMHO, a naturally aspirated truck has something wrong if it's belching smoke, so in light of that and your other posts, I'll vote for getting your fuel and timing set right. EGT's with over fueled naturally aspirated engines can get higher than a turbo motor. You can melt a piston, so be careful. 3.55's aren't the best towing gear either, but should have handled that little load fine.

 

[BigRigTech]

It's not like a steam train or anything - but there is a some smoke under HEAVY throttle.

 

[BigRigTech]

The old rig would haul this for a joke, 4500lbs of class A gravel. No dragging wheels found on the trailer......I think the CAT 301 is a little heavier than we think it is after running it for 12 hours today.

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[Diesel JD]

Hey man, the CAT website says that the 301 weighs either 3550 or 3700+ lbs depending on which model you have... don't know if your model is older or different. Those weights may be without fuel or oil and fluid. How much does the trailer itself weigh? Before I had my turbo I could make a real smokescreen pulling up a grade or towing even on a level grade with heavy throttle.... ignorance may be bliss without a pyro.... but I can't be sure.

 

[BigRigTech]

Not sure what the trailer weighs, I'm curious on that too. The 301 is the 3800lb version - the f-inlaw looked it up online through his work. I would say the trailer is atleast 1500lbs...I'm gonna run the make online and find out before curiosity kills me...