New 1989 7.3IDI owner, help!

[Hussler]

hi yall, bought my first truck, ford and diesel just a couple days ago. Its an 1989 crew cab long bed F350 4x4 7.3 IDI auto EO6 or whatever the 4 speed is called, it was the biggest truck I could find lol. Never was really a ford fan but reading about this motor it sounds like a great powerplant, and who doesnt love full floater 60's??? Its only got 76,000 miles and zero rust. Agreed to buy thursday night, at the bank by 8:30 am have the truck by 9:30, registered by 11. fixed a leaky injector, replaced the belts and headed to camp by 9pm to snowmobile, ran great all weekend!

HOWEVER, its pretty gutless. Fires right up, sounds very quiet and doesnt vibrate but it just cant get out of its own way. Its very hard for it to hold 55-60 on the highway (has overdrive). I know its not fast accelerating by design but right now I would say its questionable if it could pull my little boat. By comparison my 4.0 Jeep on 33's could easily blow its doors off. Any RPM under 2K and it just falls on its face, just doesnt feel normal.

All the fluids look good, almost positive all the injectors are firing, sounds smooth. The one thing I can think of is it doesnt smoke at all, not at start up or acceleration, shouldnt a diesel like this blow a little black smoke when floored? It got about 15 mpg highway and 11 in the city if that helps.

Heres a pic of it after a weekend of riding and some interior pics, pretty ugly all around but with some paint and love I think she will be pretty nice.

[Hussler]

Oh yeah, I got it for 2550 (had to dick him down from 2700 of course) Brand new tires, tie rods, brakes, shocks, cd deck. I think I did good. And the chicks dig it, I can see the appeal to these diesel trucks now hahaha

[chuckster57]

Welcome to the Diesel Stop!!

And congrats on your new to you truck. These things won't win a pink slip on Wednesday nights at the drag strip, but it will pull heavy weights all day long every day.

Your transmission is an E4OD, and depending on your tires and rear end ratio, it can seem slow. If you look at the federal tag on the drivers door, there will be an axle code. I am on my phone so I can't post the link right now, but I will later.

What size tires do you have, and what RPM's are you doing @ 65 MPH?


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[Hussler]

Hi chuck, The door tag says it has the C5 axle package, it also says it weighs 9200 pounds?? Is that right? The reg said like 5600. Tires are 235/85 on 16's. Didnt get it up to 65 but it was doing 61 with the cruise control at about 2000rpm

[chuckster57]

C5 is 4:10 with limited slip. You should be just about 2300 RPM's @65. The door tag shows GVWR not empty weight.


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[Hussler]

I would say 2300rpm is almost exactly what I would get. Yeah must have read the door tag wrong. So it sounds like my truck is running normal? It isnt supposed to blow any black smoke on acceleration? BTW what is the "rear antilock" light? It has antilock brakes in the rear but not the front?

[chuckster57]

I don't blow any smoke, but I am turbo'd. You may get a slight haze on hard acceleration. You only have rear ABS, my '94 does too. Sounds like all is well.


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[Hussler]

Weird, never heard of only rear ABS. Oh well on the power, would getting a new set of injectors help or any other replacement parts?

[chuckster57]

If it's running fine and not blowing any smoke then changing injectors probably won't do much other than make you lighter in the pocketbook. You can turn up the fuel for a little more, but pay attention to the need for a Pyrometer ( exhaust gas temp). Other than that, installing a turbo will the cheapest route to more power.

Here is the link for turning up the fuel:

"Fuel injection pump adjustment article"

[Hussler]

Alright, as long as it sounds like its running properly maybe I will buy one of those banks gauges and have a little fun. Unless I run across a factory kit at the junkyard I'm really not interested in screwing around for more power, this is supposed to be my work truck, not play lol.

Thanks chuck!

[NH2112]

You should be able to haul or tow quite a bit with that truck, I had a similar '88 (2WD SRW CC 5-speed) and it pulled a Jeep Wrangler on a steel equipment trailer (maybe 5500lb) on the interstate with no problem at all. Got 13mpg doing it, too.

Anyway, start with the basics - air and fuel filters. A plugged fuel filter will make the truck feel like the parking brake is still applied at higher fuel flow rates/requirements.

Next, I'd check for anything keeping the accelerator lever on the injector pump from traveling its full stroke. On my previous F350 I installed a NAPA accelerator cable to replace the unserviceable OEM cable, and immediately lost about 10mph - to hit 70mph I felt like I had to press the pedal through the floorboard. I got tired of it after a while and installed a new OEM cable, part number E9TZ9A758U, like I should have originally done. Problem solved.

After that, I'd look for dragging brakes, a slipping tranny, and low compression, most likely in that order. But I'd bet money on it being the fuel filter. Oh, and dump a bottle of Diesel 911 in the tanks, if they don't have winter blend fuel the fuel is definitely gelling to some degree and that'll cause it to bog down under a load. It looks like you're in upstate NY and it's definitely cold enough up there to gel summer fuel.

[Hussler]

A little update, it seems to be getting better as im driving it, tranny shifts pretty smooth, although its in overdrive by the time I hit 40 LOL. I'm going to jack up the wheels and check the brakes. Fuel filter looks like its pretty new but ozzing, Im assuming the Wix/napa gold is the best choice? Air filter is new. Its funny you mention the gas pedal, I think its catching on the aftermarket vinyl floor a bit, you would think romping on it would make the truck downshift but it really doesnt downshift a lot.

Okay so gelling of the fuel, ive heard some people thin it with kerosene, or is that a bad idea?

Do you guys think this truck could haul a Jeep cherokee weighing about 4k on a duel axle trailer at 70mph without hurting the truck?

[NH2112]

I'm not much of an electronic automatic guy, but the range selector on the tranny (I believe it's called the Manual Lever Position Sensor) could be out of adjustment. It should definitely downshift when floored.

Wix/NAPA Gold are definitely hard to beat for filters.

Just put diesel into it, right now the fuel at the pump is blended for expected temperatures. You CAN burn kerosene but it's more expensive than diesel.

As far as hauling a Cherokee at 70, no problem. Just downshift to 3rd if the tranny hunts for a gear, and also downshift before you hit a hill. Without a turbo you need high RPM to crest a hill without losing too much speed. Don't be afraid to hit 3000, you won't hurt anything.

[big red 94]

My 94 wont win any turtle races but It did pull a 10,000 lb skid steer out of a ditch in the woods in 4wd with almost bald tires.Just sayin to back up what chuckster was sayin about power.

[chuckster57]

I'm not much of an electronic automatic guy, but the range selector on the tranny (I believe it's called the Manual Lever Position Sensor) could be out of adjustment. It should definitely downshift when floored.

You have to be careful when you start trying to tweak the FIPL as it can cause the O/D off light to blink ( trouble code) and put the transmission into limp mode. Search the IDI forum for ""FIPL ADJUSTMENT" MLPS is at the transmission, FIPL is at the IP (like a throttle position sensor)

Don't be afraid to hit 3000, you won't hurt anything.

Even with a turbo, I have pulled some long steep hills at 2900 RPM. I don't know how how true it is but I was told that Navistar originally made this engine for equipment and was designed to run at governed limit ( 3400 RPM ?) for hours at a time.