About to Get a 7.3

[Meteshjj]

Okay, so I'm not really new to the diesel world, per se. My dad has had his Cummins since it came off the line in 1991, and we've done literally every bit of maintenance it has ever needed (but he kept it bone stock). I also had my own Cummins that I ran, modified, and eventually sold. I've also rebuilt all sorts of gas engines, but that's not really important.

Right now, I've got a 1987 Ford F-150 with a 20k 302 and a 4-speed in it.
- New 302 (5.0L) EFI, less than 20k miles
- 188k on the truck
- 4-speed granny (Borg-Warner T-18)
- 4x4, manual hubs
- Good 32-inch tires
- Shortbox
- brackets and tubing for natural gas (no tanks or injectors)
- XLT Lariat
- Power windows, power locks, A/C
- Kenwood aftermarket stereo (no amp)

So, now I'm talking to a guy who is willing to trade my truck for his 1989 7.3l F-250 diesel. It has:
- relatively low mileage
- 4x4, manual hubs
- 5-speed standard
- 3.5-inch straight-piped exhaust (No emissions and no sound restrictions where I live)
- standard cab
- long box.

According to him, it needs a regulator, but that's about it. It has lower gears (I'm assuming 3.74's or the like?), but he doesn't seem to actually know much about the specifics.

What am I looking at when it comes to big failings? I know very little about Ford diesels. Obviously, the standard checks for new cars apply:

- Coolant in oil
- Oil in Coolant
- Runs, drives, shifts smooth
- 4x4 high and low
- doesn't leave a stain
- tires are passable

I haven't actually seen the truck in person yet, so I haven't had a chance to check anything. All I've got are pictures. Mine's the blue one.

 

[Kevin 007]

Welcome to the forum!
Ask him if it has had SCA charged coolant installed to prevent cylinder cavitation. Bit of an issue with 7.3's and many other diesels. When running, listen for a ticking/chuffing noise coming from the exhaust or from the intake of the engine. Check the rubber return lines between the injectors and plastic caps on the injectors for leaks. Ask when the injection pump and injectors were last replaced, they don't last long. See how the clutch operates. If it feels wierd or very low, could be a cracked firewall or bad slave/master or dual mass flywheel coming apart. You could check for play in the balljoints. You could ask to view a true cold start to watch the glow plugs cycle fully and see how the truck reacts. Check for oil in coolant to indicate an oil cooler leak problem. Check rad for leaks and fan clutch for free spin. Check bottom of water pump for wet spots.

Good trucks and get good mileage for what they are but they do have a few things to look out for. Im sure others will chime in with more things that I have forgotten at this time of the night. Parts are cheaper for these then the Cummins or powerstroke and once you get all the bugs worked out of them, they can be a very reliable machine and work hard for you. Not a powerhouse but it will get the job done or get you where you need to go. Or both

 

[Meteshjj]

Eventually, if I get it, I plan to swap in an IDI turbo off of a 93-94 turbo truck (I hear the Powerstroke systems don't play well with IDI) to get my power up to feel at least a little bit closer to my Cummins (500HP at the wheels with 4.10 gears).

We're meeting in the middle, so a cold start is kind of hard... Both of us are driving an hour on the interstate to get there. Is it difficult to replace the glow plug system? I hear the controllers are not that great on old IDI's, so I figured I could scavenge some parts off of a wrecked Powerstroke somewhere down the line. I've also been thinking about a grid heater. The one in my Cummins let me cold-start at -30 with two cycles, and it only had one battery. From what I hear, glow plugs don't do so well.

Is there a way to test the coolant for SCA additives? I've also heard that rusty tail pipes or acidic coolant is a good indicator of cavitation... Or at least cavitation that has gone too far.

 

[79jasper]

Well... When it comes to starting, you can't really compare idi to a do Cummins.
But a grid heater could help. Not exactly needed though.

Look through the FAQ section. You can test the coolant.
You won't get anywhere near 500hp at the wheels (well unless you have a few money trees, even then.....)
Powerstroke turbos will work, just takes some custom fab work.
Psd gp parts will not work on the idi. Only the relay. On the psd the GP's are controlled by the computer. Idi has it's own standalone controller.

He says it needs a regulator, only regulator I can think of is the voltage regulator.

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[Meteshjj]

He says it needs a regulator, only regulator I can think of is the voltage regulator.

Yeah, it's the voltage regulator. I guess I should have been specific.

Well... When it comes to starting, you can't really compare idi to a do Cummins.

When it comes to anything, I don't think a Ford can hold up to a Cummins... I know I won't pull anywhere near 500 HP, but I'm hoping to hit 250-300 at the wheels, which is a lot better than my 302 has. I think if I dyno'd it, I'd probably find maybe 150, if I was lucky. It's more gutless than my carbureted 318 with an automatic behind it.

Psd gp parts will not work on the idi. Only the relay. On the psd the GP's are controlled by the computer. Idi has it's own standalone controller.

... Oh. So where do I go for a good glow plug setup? If I'm going with grid heater, I plan on eliminating the glow plugs entirely, but barring that, I at least want a reliable computer for the plugs. What's the best option?

 

[79jasper]

Well you could possibly build a controller.

What do the Cummins use as a timer for the heater?
I would use that.
Really the glowplugs will work just fine. Put new GP's in (beru's or 60g's) make a new harness with bigger wire, get a HD constant duty relay, and put them on a momentary switch.

Voltage regulators are cheap and easy.

That power level is more feasible.

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[Meteshjj]

A Cummins has its own computer for controlling the grid heater... They are absolute crap. I changed mine to a relay switch with a big red light on the dashboard.

As a Dodge owner, I know all about changing regulators. I keep a six-pack of them under the seat of my Charger because they die so damn often.

So, for the coolant, I can't find a way to test for SCA in the coolant. I know I can test for the exhaust by testing pH, as well as some other fun tools and chemicals, but how do I know if the coolant in the system has any SCA's in it?

 

[CDX825]

The 83-86 glow plug controllers were the problematic ones. The 87-94 system works good so long as you use good glow plugs.

 

[Meteshjj]

The 83-86 glow plug controllers were the problematic ones. The 87-94 system works good so long as you use good glow plugs.

Oh. Well, in that case, I won't worry about it. As long as the controller I've got isn't prone to failure, I'm happy. Like I said, I know nothing about Fords. If I could find a Cummins this cheap, I would, partly because I know way more about Dodge. The Devil you know, right?

 

[Wyreth]

When it comes to anything, I don't think a Ford can hold up to a Cummins... I know I won't pull anywhere near 500 HP, but I'm hoping to hit 250-300 at the wheels, which is a lot better than my 302 has. I think if I dyno'd it, I'd probably find maybe 150, if I was lucky. It's more gutless than my carbureted 318 with an automatic behind it.

Hate to tell you this, but while 250hp at the rear wheels is pretty doable from an IDI. It takes quite a bit of work, and some pretty decent money. Likely more than you payed for the truck.

(also, the "lower gears" in these trucks are 4.10)

First things first, read the FAQ sticky and the "start here" thread. Then go through the Tech articles. That should give you a general idea of what you are getting into.

 

[79jasper]

Should be instructions and information in the FAQ about testing the coolant.

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[Knuckledragger]

Your power needs are dictated by the uses you plan for the truck. If you tow a lot, you will need to have a turbo, which will not change the HP rating a lot, but increases the torque value, which is what really gets the work done. GPs are easy to change and burn out on occasion. Injectors are even easier to change, no valve cover removal.

IDI engines are simple, sturdy, dependable and inexpensive. The last one is why most of us own and drive them. They aren't ****, powerful or super fast, but they start up and run and take you anywhere you want to go, drinking about anything you put in the tank.

 

[Kevin 007]

I agree with the above. If your looking to make big power even 250hp, id' be looking for a different setup. These are work trucks, not hot rods and the amount of work need to make that kind of power is hard to justify, "IMHO". They are perfect for my needs, but thats just me.

 

[79jasper]

Hate to say it, but For the money of the truck + repairs + upgrades, you'd be better off with a Cummins anyways.



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[riotwarrior]

Welcome to OB, sounds like you have some plans and such for this swap of trucks.

What is the main purpose of the truck if you swap for the diesel?

In all likely hood 250 hp is achievable however it's a tad $$pendy to get there. A stock turbo, likely won't getcha there.

Figure on a cam, look to Typ4 aka Russ for a cam or Justin from R&D and as well some mild head work and custom turbo and a good decent IP be it a Moose from Mel at Conestoga Diesel or Justin at R&D

Both offer pumps, Mel is well known around here for sure as a premiere builder of the Moose series of pumps.

As mentioned go through the FAQ and such, and Tech sections, lots to go with in there, and Hall of Shame so you keep your hard earned $$$ instead of feeding the sharks yer coin.

SEARCH through the articles, you'll find that these rigs are decently reliable and usable as they come.

As for GP's if you have a decent system with good wiring they are a decent setup. It is when the GP system is 20+ years old and wires degraded, corroded etc that ***** starts slanting down the slippery slope of unreliability.

As with any used truck it needs to be considered as a work in progress and how much work you are willing to do depends on what you are willing to invest initially on a good truck vs a worn out one, vs time/$$ into either.

Good luck with your choice, let us know what you do.

Again welcome to OB

Al