1991 Uhaul F350

[Tual Phurmond]

I bought this years ago and used to haul my race car with it. It would top out at about 60 mph. Does anyone know if Uhaul had a governor on the 7.3 IDI's and if they do where is it located and how do I remove it?

 

[laserjock]

Welcome!

There is a governor in the pump. I don't know if U-Haul did anything special but I have read that international set the governor for a much lower RPM than Ford. I suspect that you may be gearing limited as much as anything. It's probably got 5.13's or something like that in it. May be a combination of the two. What RPM are you getting out of it? Don't hold me to this but I want to say Ford set the limit at like 3400 and International was 2800-2900?

Bottom line, most people shouldn't attempt to mess with the governor as it is an internal component to the injection pump. The guys with the U-Haul engines and pumps have never mentioned anything about removing any external governor that I have seen.

 

[Tual Phurmond]

Its been so long since I drove it I can't remember what the rpm's are or if it even has a tach? I was thinking about getting ready to turn this into a wood hauler and thought there might be something done by Uhaul to limit the speed. I'll have to look into this more and get back on here once I refresh my memory. Thank you for the reply.

 

[chris142]

I'm sure that UHaul did everything possible to prolong the engines. Not sure how they could govern the IDI other than a special low rpm pump.

 

[typ4]

What trans does it have? axle code will be in the door sticker. throttle cable may be stretched.

 

[Tual Phurmond]

I'll try to look at this tonight when I get home.

 

[icanfixall]

Welcome to the forum. International did install an injection pump with a low governed control so these trucks ran slower on the roads. Inside the top of the injection pump is a spring that can be replaced but if you have never been inside these pumps it can be a disaster. I do not recommend changing the spring. The spring limits the engine rpm to as posted. About 2700 rpm or so. Now we can even upgrade these springs to the one found in the chevy 6.2 or 6.5 injection pumps. Those springs allow the the governed rpm to be up around 4400 rpm. Many here feel that is spinning our heavy internal parts too fast for safe engine operation too. The chevy injection pump will not fit our idi engine either. The rotate backwards compared to our pumps. So the easy way of increasing the governed engine rpm is to purchase another injection pump but make sure its been made for the F series or the E series trucks or vans. I see you have a U haul F350 so I can't say for certain what pump is on that engine. Knowing the trans type and the rear gears may help understand what this truck build is.
I found the relay testing.
http://easyautodiagnostics.com/ford/4.9L-5.0L-5.8L/eec-power-relay-tests-3#4

 

[Tual Phurmond]

Thank you all for the advice and information. I will try to check tonight when I get home. I like the simplicity of the 7.3 IDI but sure miss the get up and go of my Powerstroke. There seems to be alot of the IDI's out there and I wouldn't mind getting to know these engines better. I like the simple trucks. My daily driver is an 89 F250 4X2 with a 302 in it. People laugh but I have no truck payment and PLPD insurance.

 

[OLDBULL8]

As said, you don't want to mess with the Injection Pump (IP), to get to the governor spring, the top has to be all disassembled (see pic), then re-assembled correctly or you will have a runaway engine that will destroy itself.
As far as I know, U-Haul bought Diesel trucks in a Fleet purchase with the IP's governed at 2900 RPM.

U-Haul went from Diesel engines to Gas, don't remember the year. too many rental IDIOT's couldn't or didn't read (DIESEL FUEL ONLY).

 

[Tual Phurmond]

I would like to learn how to mess with the injection pump sometime though.

 

[FORDF250HDXLT]

the f350's only came with 3.55 or 4.10's.so even if you have a c6/4.10 combo she should still do more than 60 lol.
i vote for this issue:

throttle cable may be stretched.

it's a simple test.have someone press the accelerator to the floor while you watch the cable at the ip.while they have it floored,see if you can still move the throttle linkage more.if so,you need a new cable.
a quick test we can all do when we first buy the trucks and then once a year after.

 

[Tual Phurmond]

You must be registered for see images attach

Here is the tag on the door jamb. Its been so long since I messed with the old girl I forgot it was a 1990! !

 

[Darrin Tosh]

The tag pic didn't show up.

But if it is C6 trans (no overdrive) with 4:10 gears, and a governed pump, the top speed wont be much over 60, good possibility the tires are only a 215-85-16, a short tire compared to today's duallys. that will limit your top speed as well.

It depends on how much you want to to put into the truck, but a rear gear swap to 3:55's would help, and the big dollar upgrade would be a Gear Vendors Overdrive Trans.

Good thing with your problem it is nothing that Money and Time cant fix! ,

 

[Tual Phurmond]

When I click on it in my post before yours it does?

 

[OLDBULL8]

When I click on it in my post before yours it does?

Yes, it will show up in your post, because you made the post.

You have to go into "Go Advanced" then to "Manage Attachments" then upload your picture.