First post here as just joined but been on other forums so get the jist of them.
----A little bout me so you know where I'm at with knowledge with 7.3's or other automotive diagnosis---
-I went to school back in 94 for automotive tech (glorified word for mechanic) and went for the first 9 months of a 2 year program. Mainly, we studied the electronic part and/or diagnosis part of vehicles and engines/drivetrains. The mechanical learning portion of the engine/drivetrain part was the next year, (which I missed), but alas, I ended up working at a Ford dealership out of school and learned alot of that on the job. Not to mention I read a lot about engines so I got it that way too.
The dealership was in my small hometown and since I had schooling of diagnosis and electronics, that was eventually where more of my expertise/knowledge was put to use. Mainly because the other "veterans" didn't like working with the newer electronics in vehicles and liked doing more of the mechanical work like rearends, trannys, engines, and etc. Although I did a lot with diagnosis and electronics, I also did heavy work too and ended up being one of the first to overhaul a 4.6 (at the time our dealership was told it was taboo to try to rebuild them) out of a cop car when they came out and also a 7.3 turbo Diesel (heavy bastards) back in the day (I think it was around 97 or 98). Anyway, I worked on the 7.3's and remember the injector O-rings being one of the main issues with them especially when it came to farmers using farm fuel when they first came out. As such, I replaced a lot of O-rings so I know that's a must for these engines but outside of that, with the exception of fixing stock/factory things like clutches, replacing trannys, water pumps, and a few other things, I don't know much about them since I never owned one. I did work on a lot of different things on them over the years so I have a decent amount of knowledge about them but that was 12+ years ago. But that's my knowledge with them. Fast forward to now----
So, I don't want to be that jerkoff newb like so many are on forums and bypass reading and researching threads
but have a few questions that maybe some of you could simply direct me to if you can remember a few threads vs. me sitting here for the next week or month trying to find what I'm looking for when a few of you could probably direct me to what I want with a few links or suggestions of where to look.
Your help would be much appreciated. If you don't want to help, I understand and I will still do more research as I have already started to but as you know, there is so much info on this site that it could take a while to weed through some of the posts to get what I want.
There is a 1995 F-450 flatbed with a 7.3 & a 5-speed manual for sale that I'm looking at that I feel isn't too bad of a price. It's at about $2200 with about 290,000 miles on it. It's a dually and is 2 wheel drive.
Sure, the miles are maybe a little high but as we know, for a 7.3, not really if it was well maintained but of course we can forget knowing that for sure because anyone can say that they keep their vehicles "well maintained" without documentation so until I see proof, I just figure it probably wans't kept up very well.
So here's the scoop:
1. I went to start it for the first time and it was relatively warm out that day (about 70ish) and it took about 8-10 seconds for the "wait to start" light to shut off (no biggie as it seemed about normal). As such, I tried to start it after that but it needed about 6-8 seconds of cranking (might have been 10 seconds I can't remember) before it finally started. Now, it wasn't extremely long for cranking time but did take longer than a typical 1-4 second crank that I'm used to on these engines so I have a concern right there.
--So, any thoughts on this? Should I be concerned or just figure on replacing glow plugs anyway and be done with that or look at something else?--
2. The sellers told me that the "fuel in water" light stays on and I didn't notice that but figured that this can be as easy of a fix as changing the fuel filter.
--What would your thoughts be on this? I called Ford to get a price for a new sending unit/sensor for this light and they said they don't make them/can't get them anymore so I would have to find the sensor myself from a different source. How concerned should I be about the light being on? Although I have worked on the diesels, I'll be honest, I don't know much about a diesel engine other than it has higher compression, runs on diesel fuel and they typically "gel up" in the winter time so you need to be careful about when it gets really cold out.--
3. When I looked at the rearend tag, it said it had 5.13 gears in it.
Yikes. So, I already know that I want to change the rearend gears since I want to do some highway hauling with this truck. With it having a 5-speed and knowing I'll be the only one driving it and already know how to drive a manual, I'm not worried about ruining the clutch and so on and think something a LOT lower would be better for highway traveling. 4.10's would probably be good but I'm thinking 3.73's to get even better mileage. My thought is if I'm traveling through hills with a load, you can always downshift right? But come highway traveling, I don't want to be revving above 3000 to go 65 or even 70ish.
4. When I drove it down the road, it vibrated fairly bad. The tires are shot (pretty much) so I know that will be the first thing to fix and of course I'll have to check out the front end to make sure everything is tight. I checked the driveline on it and it actually has some recent tags on it from a driveshaft company that says it's been balanced so they must have had some driveshaft work done to it recently. Also, the U-joints and so on seem to be tight and in good working order so the vibrations/shaking must be from the tires. It's a big F-450 so I don't expect it to ride great but it was pretty bad.
5. Power - I've driven enough of these old 7.3's on test drives and so on too know the power they are capable of and this did NOT have that snort at all. Now again, don't get me wrong because I know that a big F-450 dually is going to weight a hefty amount but the reality is, it probably weighs less than a 4-door F-350 with a long box on it and I've driven a few of those and remember them getting up and moving just fine. So, I've got a HUGE concern about power at this point. As for starting and running, once it started, it idled fine and the turbo sounds heathy when revved so I'm not thinking that it has any "obvious" issues but something else. It had a little cackle to it like perhaps it has an injector out but I remember that a few times all that this was was some bad O-rings on those injectors. A new O-ring kit sealed them up good and made that engine purr and run great. Again, it sounded pretty good and didn't have a bad idle that was lopey. So, I'm wondering what the power issue could be at this point. Obviously, it could be 100 different things.
--My hope is to get a scan tool on it and run it through the injector balance test if at all possible and run the other scans on it to see if there are any obvious codes to take care of first. If I can do that, I know that will help. But if not, are there any tests I could do without a scan tool to see about figuring out the power issue? At about 55 mph, it's pulling about 2700 rpm's but I'll attribute that to the darn high rearend gears (5.13's).--
6. The vacuum pump must be bad or there is a leak in the vacuum system into the cab because the defrost is the only setting that the ventilation system goes to. Of course that would be an easy fix for the ventilation duct system in the cab but I'll assume a bad vacuum pump could be causing some of the other power issues with the engine itself too. I can't remember what the vacuum pump runs on the diesel motors but will assume they are pretty important for the engine to run well.
7. --Modifications-- I don't want to spend an arm and a leg on this truck but would like to do some simple mods to gain some hp on this vehicle. I'm thinking more simple (least costing) mods that would maybe total around $400 to $500 max and would like to stay away from needing to replace the injectors if at all possible. I know I will have to put some money into tires for this vehicle so I'm thinking if I could build my own air intake, I would do that. I think there has been talk of that on this site hasn't there? Or am I mistaken?
Also, I have heard about getting chips for these engines to boost horsepower anywhere from 50, 75, 100, and even 140 hp over stock for around $225. Are these legit things to do or is this a boggus claim by these companies? Would I need to worry about anything with a stock motor with around 290,000 miles on it? Can I buy an used chip from someone or can I have the computer programmed at Ford? I remember when I was working on them that we had to "flash" the PCM's for a few things but I don't think that this actually raised the power levels on the engines at all. So, are there any simple mods I could do that wouldn't cost anything? Can the current PCM be reprogrammed for more power for free or would I have to send it in?
I read on one thread about taking off the flat exhaust pipe right from the turbo and taking the exhaust off completely to gain 40-50 hp and that although it would be a little louder, it wouldn't be too bad for the cops to be ok with and would really just increase the turbo whine/whistle. Would it be ok to just take the exhaust completely off from the turbo and run it wide open with no exhaust? Would there be anything I would need to worry about if I did so? Would it hurt anything?
--Thanks in advance for your help. Even though I have "some" knowledge of these engines, it's always better to get more help from some of you that have the "been there done that" t-shirt.--