Work horse or pig

[Jtdogbear]

I dont know how this site works so pardon me if i get it all wrong but i have a nagging question for those who know. Ive had a 92 f250 sclb 4X 7.3 natural idi for many years. I love the truck, she’s always always gotten me there albeit VERY slowly at times. I’ve always accepted that (sort of) since the first thing you ever hear about the early non turbo (and turbo for that matter) 7.3 idi is how gutless they are. I don’t care about blowing smoke or burning rubber but it would be nice to pull a grade in the same day! So just how lame of a performer is my motor? I switch off the OD on my E4OD while towing anything heavy. She has 4.10 gears and stock tires, runs really nice and has around 200k miles. With 5 or 6000 lbs behind her I can barely hold 2nd gear on (guessing here) about 5% sustained grade. I’m always happy and relieved to crawl over the top with 50 cars behind me. I can look at HP, and torque specs but what does that mean in the real world? For example with maybe 7000 lb in tow I can be approaching a normal hill (flat land minnesota here) at 2500 rpm w OD off (around 60 mph) and I will steadily loose speed and have to drop into 2nd if the “grade” is more than 1/4 maybe 1/2 mile sustained. Is this “normal”? BTW, I’m not interested in performance “upgrades”. I think if stock this motor is that bad I’ll just deal with it as I have for 20 years, or I’ll finally and with great reluctance get a new old truck that will pull. Your thoughts idi gurus?

 

[mexicanjoe]

Have someone look at your IP. Out here in flatland Texas, can pull a fully loaded 23" gooseneck livestock trailer down the road, at 65-70 with a/c on. Mind you I have a ZF5 and 4.10 LS rear. Top speed ?? I dont care to know-probably 85 mph but then I'm not looking for speed, just pulling power on dirt roads.

 

[Nero]

I'd say for a n/a engine thats pretty on par. Before I turboed my truck I could barely do 45 on any mild incline with fully loaded camper and boat in tow. Even hitting it running I'd slowly creep down in speed.
I know you aren't interested in any upgrades, but a bolt on turbo kit on a stock engine is miles better than a n/a engine. Crazy how much even a little boost wakes these old dogs up.

 

[Clb]

Everything is subjective, that said you (in my opinion anyway )should be in 3rd .
I towed a 6k 5er ( dry weight) to Ak and back.
It only once was doing 40 mph.
But it's turbo'd and 5 gear...
How old is the injection system?

 

[Greenie]

I've towed a 7,000+ pound travel trailer a lot with a stock 7.3 IDI 4.10 E4OD, 80 mph on level ground with no big headwind. It slows on grades or headwinds but it's still reasonably powered IMO. I also towed in OD unless the transmission searched a lot, but that is dealt with by not giving a full throttle up grades, backing off a little to use the power that's available. It's no pig.

 

[Jtdogbear]

Mine is 100% original stock condition with like i said 200k on the clock. I’d love to have a manual and think being able to drive it, instead of Otto running the show, it wouldn’t be a PIA. I’ve had terrible luck w other trucks w the E4OD so I never work the truck w/o switching the OD off. But like I said I pretty much have to manually drop it into 2 and leave it there on anything relatively long and relatively steep with a load. I’m ok w that but really jones for a 5 speed. Sorta sounds like my rig is “normal” more or less? Just seems really lame for a real truck. My 4.7 v8 toyota did damn near as well the few times I HAD to press it into trailer towing service. I maybe would consider a turbo kit or maybe part with her and get a later factory turbo idi w 5 speed. If you can find one for less than 20k! Then the seller will lie to you or not know about SCA so that’s a gamble. At least I know mine. I had been driving it 20 years at work until I got to buy it for a song a few years ago.

 

[FrozenMerc]

Some improvements can be made with tuning, pumps, air intake, exhaust etc, but at the end of the day, you have a N/A diesel coupled to a slush box, power eating automatic. Towing and climbing grades are not going to be it's strong suit.

I drove mine for many years with the N/A 6.9 with a manual 4 spd + OD. Even made the trip between NW Minnesota and SW Missouri a number of times pulling a 24' Pace enclosed (10,000 lbs) during the moving process. And yes, I was always the guy in the slow lane, especially in the hilly areas (I-29 across SD, and the Ozarks.). After nuking a head gasket that resulted in a cylinder hydro-locking and a cracked main bearing web during one of the moving trips, the short block got replaced with a 7.3. Shortly there after, a CDD Turbo and 90 cc pump got added and eventually a ZF 5 spd and changed from 4.11's to 3.73's out back. Now the truck is a pulling beast. I made my final trip this past September to get one more project I had stashed away up in NW Minnesota. Pulled out of Warren heading south into a 30+ mph headwind, the truck held 60 to 65 mph in 4th gear despite the ridiculous headwind and the 15,000 lbs and one giant parachute hanging off the back. Stayed the night in the Brainerd Lakes area before heading south the next day. No wind then, and had no trouble cruising at 70 to 75 in 5th gear down I-35. Had a truck driver about lose his mind at a truck stop in Northern Missouri, because he did not believe me that an old IDI could pull like that (I had passed him a few miles earlier, climbing hills). He made me pop the hood to prove I hadn't Cummins swapped it.

Long story short, If you want it to perform like a more modern diesel. Turbo and Pump upgrades are required.

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And, as far as the 1960 C700 on the back of the trailer is concerned. I already have a 7.3 IDI sitting in the shop that will be going into that truck soon....

 

[Black dawg]

Check to make sure you are getting full throttle at the pump. Very common for these cables to get stretched out.
Power doesnt seem too far off of stock na 7.3, but maybe slightly less than what I remember my truck being, with 4.10 and e4od and between 7 and 8k behind the truck.

Does it smoke much pulling a load?

 

[Jtdogbear]

Thanks all for the replies. FM, that’s a good story and definitely gives me something to think about. Sorta looking for the truck I will die with. My 92 is pretty close and I could definitely follow a few suggestions here and live with what ever power results I gain. But my must haves for my “last” truck are super cab, long bed, 4X, manual trans, and with my budget that will probably be another OBS ford and in a perfect world, a 350 to depart from the IFS. Also B dawg, I had that same thought and seeing no adjustments on the cable assumed it worked or it didn’t. But i didn’t consider the stretch factor. When i jam a stick in the floorboard the truck I can manually move the speed on the IP just a little. Not much but definitely there is a little more there. So I’ll try that cuz it’s so EZ. Maybe just put a little spacer between the pedal lever and cable or even try to bend the lever a little? Anywho …. Thanks again y’all for thoughtful replies etc!

 

[Jtdogbear]

And no, I don’t notice unusual smoke. Just steady loss of power. In fact, though I haven’t tried, I doubt I’d see >70 pulling a load in the flat windless low lands w pedal to the floor and 10 miles of road.

 

[Clb]

How
Many
Miles
On
The
Fuel injection
System?

 

[Clb]

T.c. slipping?/locking up?
Timing?
Same fuel source each time usually?

 

[Jtdogbear]

Far as i know nothing as ever been done, so fuel system has same as truck, 200k miles. Trans and TC seem normal and fluid looks normal. No idea about timing but starts and runs really well, except the power issue as described (if it even is an issue?) I buy fuel where ever when ever and haven’t noticed improved to diminished performance fill to fill.

 

[Nero]

Fuel systems on these typically start fatiguing after 100k. My in laws truck had 220k on original fuel system. Ran fine, but had mild smokey exhaust at idle. Did have a lil power loss under load, and it was also the e4od.
New pump and injectors and it now has perfectly clear exhaust and more power under load. Not much, but noticeable.

 

[Jtdogbear]

Thanks for input, I am stating to feel better about not “fixing” it until it’s broken. How much screwing around for seems like pretty minimal gains? I guess it may find it’s way to the bottom of my already too long to do list…