1991 F-250 7.3L value
#1
06-05-2017, 08:48 PM
1991 F-250 7.3L value
Hello everybody, first time poster here. I am completely new and inexperienced with diesels but have a lot of time in working on and modifying gas engines. I have been looking for truck to do some light (ish) towing this summer, 20 ft boat and maybe a car trailer would probably be the most I'd ever pull. I was really looking for a 460 or maybe a 351 when I came across a 1991 F250 7.3 idi for sale. It intrigued me so decided to go look at it. I done a little research prior so I'd at least have an idea of what to look for. The truck was 100% rust free. None on the bed, cab corners or rockers. I crawled all around underneath it and there was simply none. Interior was fairly good given the age, seat and door panels had some wear but that's it. No real history other than what this guy has done which would include glow plugs, starter, and battery. He said he had never replaced the injection pump or injectors.
So, when I cranked it cold, it took 3-5 seconds to hit but I kind of expected that. I drove it for probably 10-15 minutes and then I turned it off. When I went to crank it back, it still took at least 3 seconds or so to hit. I done this several times and each time it took a few seconds to hit. Is this normal? I was afraid the injector pump could be weak. But, the truck ran absolutely great. It had plenty of power and the transmission and transfer case shifted like butter. No smoke except a small puff when I hammered down on it. I noticed a small leak coming form the transfer case though. The truck is a "camper special" and apparently has 1 ton axles with the "extended" looking hubs for the addition of another wheel. He would not budge off $3k. I offered up to $2600 but he wouldn't move. Is it worth the $3k? I figured a rust free truck is pretty hard to find right? I don't know, I don't want to sign up for hours of work and tons of new parts though.
So, when I cranked it cold, it took 3-5 seconds to hit but I kind of expected that. I drove it for probably 10-15 minutes and then I turned it off. When I went to crank it back, it still took at least 3 seconds or so to hit. I done this several times and each time it took a few seconds to hit. Is this normal? I was afraid the injector pump could be weak. But, the truck ran absolutely great. It had plenty of power and the transmission and transfer case shifted like butter. No smoke except a small puff when I hammered down on it. I noticed a small leak coming form the transfer case though. The truck is a "camper special" and apparently has 1 ton axles with the "extended" looking hubs for the addition of another wheel. He would not budge off $3k. I offered up to $2600 but he wouldn't move. Is it worth the $3k? I figured a rust free truck is pretty hard to find right? I don't know, I don't want to sign up for hours of work and tons of new parts though.
#2
06-08-2017, 01:41 AM
Diesel Wrench
How many miles does it have? The old 7.3's are good motors, but are prone to cavitation. I would ask if he has maintained the SCA/DCA levels in the coolant to prevent cavitation from happening. Here is a link to better explain cavitation.
Understanding Cavitation in the 7.3L IDI Diesel
If the mileage is in the 200k range, the price seems high to me. Over here you can get those old IDI's for $1500 and up with that kind of mileage. Most people will suggest you change the IP and injectors every 100k miles. The injectors are pretty cheap and usually not to difficult to do, the IP is about $500-$600 if you go with a stock replacement. I would also ask what brand of glow plugs he installed. The Motorcraft plugs are the only ones you want to use. The other brands tend to swell up and can become difficult or impossible to remove. Sometimes they can break off in the prechamber and then you have to pull the head to get tip out. I've removed 2 sets of swollen Autolite glow plugs in the past, got lucky and none broke, but it was pretty nerve racking working them out.
Understanding Cavitation in the 7.3L IDI Diesel
If the mileage is in the 200k range, the price seems high to me. Over here you can get those old IDI's for $1500 and up with that kind of mileage. Most people will suggest you change the IP and injectors every 100k miles. The injectors are pretty cheap and usually not to difficult to do, the IP is about $500-$600 if you go with a stock replacement. I would also ask what brand of glow plugs he installed. The Motorcraft plugs are the only ones you want to use. The other brands tend to swell up and can become difficult or impossible to remove. Sometimes they can break off in the prechamber and then you have to pull the head to get tip out. I've removed 2 sets of swollen Autolite glow plugs in the past, got lucky and none broke, but it was pretty nerve racking working them out.
