93 IDI E40D Towing Question

[Titojeep]

Alright guys, it's titojeep back again for help. I had my first long distance towing excursion last week while on vacation. All of the prep work and general tuning has gone fine so far, but I have a serious question regarding towing specifically speed, temperature, and general good operation. I just finished sorting through an hours worth of threads and found much value in your various input but I'm still not clear on what I should expect as normal.
Being my first IDI and hearing all the 7.3 tall tales of pull what you want, I'm concerned about what I saw on my 1000 mile round trip journey pulling 4200lbs with another 1100lbs in the bed.

For starters, 1993 IDI Crew cab dually, 4.10 with E40D (rebuilt 11,000miles ago) and 210,000 on the clock with new pump, injectors 5000 miles ago.

Condition 1

Trip was through TN mountains across various roads and hwys. 1st observation: Highway traveling flat - ran 60mph at about 2200rpm. Temperature would go from the normal (N - O range on factory guage) up to (R-A) area. I would hear the fan ramp up and notice the temperature drop back down. Also note, it was an 85 degree day and running the AC.

Question: Based on what you've stated on various post, it's normal to see the temperature rise and fall, as long as I hear the fan doing it's job? I just assumed that being a diesel with only half of what it's capable of towing wouldn't see the up and down of the temperature so frequently. Note: Trans never shifted up and down, and when I encountered slight grade, it would stay in OD and I'd see a steady stream of blackish smoke, but it would stay within it's set (cruise control) speed.

Condition 2

From flat land to the hills (roughly 3-4% grade) sharp drop in speed. Went from 59-60 to 35-40. Black smoke lugging OD until it shifted down. Pushed the throttle to get RPM's up to 2300 or so and worked that until the top.

Question: Is that normal with only 5300lbs? Note: Shifting is normal in terms of depressing throttle through power range, however I noticed from 60 lugging down untll around 40 before kicking in a higher RPM was odd for me. But maybe I'm just too used to gas motors.


General Question: What's the best way to throttle the motor during towing for engine and trans life? My question is based off the observation that keeping speed didn't seem to be a problem on the flat land, but I saw the black smoke and it made me wonder if it's O.K. for that to be happening, or should I be winding her up in the 2500 + rpm range. I've heard you're advise on keeping it out of 3000 rpm for longer life. Didn't know if lugging was a bad thing since technically max torque is in the 1400 rpm range right?

Look forward to your advise and input. On a seperate note I should have stated that I am in the process of looking for a complete set of "real" guages and I intend on installing a larger trans cooler as well. Just for the heck of it, I pulled over when the temperature was in the R-M range (before the fan clutch kicked in) to scan with my IR gun and the top hose of the radiator was at 195 and the trans pan was at around 193-199 depending on where I scanned.

Thanks

 

[david85]

You want to avoid smoke lugging the engine if you can help it. Bad for EGTs, bad for the rings getting coked up, and bad for fuel economy. If gearing down and bringing the RPMs above 2500 allows you to hold speed without the smoke, then gear down. Higher RPM with less or no smoke is what will help the engine live longer. Smoke lugging is what wears them down over the long term, or in the short term can cause damage quickly if your EGTs get high enough.

I personally prefer not to go above 2500 simply because I never have to, but 3000 RPM won't kill it either. These engines are designed to run near the governor for extended periods.

The only thing concerning me is the transmission should have downshifted automatically. I wonder if you FILP sensor is a little low. FILP = Fuel Injector Pump Lever (sensor) basically its your throttle position sensor. Ideally you want around 1V at idle and 4V at WOT.

When driving, try to hold a fairly steady throttle and allow speed to build up a little before the hill and bleed down while climbing the hill. These engines are not power houses and you will have to live within the limited power you have by anticipating hills.

Not sure about the fan, but as long as it is forcefully controlling temperature even under those conditions, I don't think you have much to worry about.

 

[OB_WAN]

after buying my truck, I tried towing a heavy load up over a pass ~8k elevation. I was pumping serious black smoke and dropping to 25mph. the truck kept lugging shifting up and blowing smoke. After that trip I did a lot of research on this site and found out about what david85 was stating. I hope I didn't hurt my engine.

Here's what I do now. For better or worse(note I have a turbo now but this is based on smoke and the trans, not air induction):
1. as long as I'm cruising w/out any significant drag(drag = blowing smoke @ lower RPMs), I'll keep it in OD.
2. as it starts to lug down, I kick on the tow mode, on-the-fly. I'll run in 3rd as long as it's not blowing smoke. I'll keep the cruise on through the process
3. if I start getting in to steep inclines, rather than hammering down the throttle to force a shift in to 2nd, I'll turn off cruise and manually downshift to 2nd and run out the incline @ a safe throttle(not blowing smoke or at least blowing minimal smoke). I keep the RPMs up ~3k.

Let your gas pedal control the smoke(or lack thereof). Don't work too ******* keeping the speed up. a healthy engine is more important than speed.

I wouldn't mind others commenting on this since I'm not sure if I'm causing problems for my transmission. I know I'm keeping the trans temps in a safe range. Only thing I worry about is manual shift in to 2nd @ freeway speeds and toggling OD.

 

[Titojeep]

Thanks for the replies. I was wondering about the FILP set up since it's a new pump. I had someone install it for me and haven't noticed anything weird in terms of shifting during normal (non towing) operation. I will point out that this being my first diesel and this being my first long haul towing something with a diesel I may have been too critical on my evaluation. I never actually had to go to WOT (wide open throttle) during any of the slowdowns. I merely kept it below 2500 rpms and let the cooling fan do it's job.
As for the OD off button, I did noticed that if I turned it off just before I new I was dropping speed to quick that it would simply step down (I assume out of lock up?) and raise the RPM's slightly as opposed to waiting until it lugged down so much that it shifted down on it's own and them screaming to 2600rpm +. I'm sure that's not for the long term either.

Thanks

 

[RLDSL]

When towing on hills, you want to keep it at 2500 or above if you want to keep it cooled down. You are not going to save any fuel lugging it down in fact you will use more fuel keeping it in a higher gear and having to mash on the pedal, if you just drop a gear and let it wind up and back out of the throttle the engine won't strain as hard and you will use less fuel

 

[sootman73]

the OD drive off button does exactly that. it shifts into third gear and keeps the converter locked. no way i would want to tow a grade with the converter unlocked. tat would be a lot of heat! Being able to manually select your gears is a must when towing through hills. it wont hurt unless you over-rev your engine by downshifting at too high a speed for that gear. other than that its okay.

 

[FORDF250HDXLT]

dont be afraid to mash that go peddle before the hill.plant it and hang on.you want her talking back like she's ready before you get there.
your not going to hurt it.
max hp in a stock engine is at 3k.hp is your momentum.
letting her slow down so you hit 2nd is not the answer.keeping up speed and rpms is the key.
the only time i see 2nd is with some serious weight,and serious hills.nothing wrong with 2nd once she slows down and asks for it either though,just keep her to the floor(if your under the speed limit.)
dont be afraid to work 'em on those hills boys.
lugging and black smoke is something iv never seen.
average speed of 50mph over the course of 11 tanks is pushing 16mpg with a large wind catching bed.
3k rpm's isn't going to hurt that diesel one bit.thats where IH has her set for peak hp.we dont have much in the way for hp,so when you need it.....use it all. (when you don't,use OD and lowest rpms/speeds you can live with.)

in short,i agree with RLDSL 100%.