1991 E350 7.3- vapor lock issues

[rover215]

Hey everyone-
First time post but I hope to be more active soon. I might buy a '91 E350 that's having vapor lock issues. I don't know the miles of the engine or if it's even a turbo, but the seller is a friend and would sell it to me for cheap. I'm in Portland, OR and he's in Chicago, so resolving this vapor lock issue is vital. He makes it sound like it's not been a big deal, but driving three time zones makes it a big deal.
Any particular issue with theses engines? If the miles aren't in the 300k range, the tires and brakes are good, and the engine runs well (aside from the vapor lock) then is $800 a fair price? It's a former fleet vehicle cargo van and has been used as a tour van for my friend's band. What do y'all think? Thanks for any help!

Matt

[elibenson]

There were no turbo diesel vans before 1995, so it's definitely not a turbo.

Vapor lock? Are you sure? I have never heard of a diesel having vapor lock. Diesel just doesn't vaporize due to heat like gasoline does. I am thinking more likely that you have an air leak in the fuel system. Those fuel return lines on the fuel injectors have a bunch of rubber hoses, o-rings, and plastic parts that could use replacing. More than that, the hard fuel lines have rubber washers in their fittings that tend to break down over time.

There is a kit you can buy at Orielly's or Auto Zone that has all the plastic parts, o-rings, fuel line, and clamps (called an injector install kit for ~$60) that will solve most problems. The kit also comes with new copper washers to install new fuel injectors too, but you don't really need that part of the kit. The hard fuel lines might need new washers that may be available from a local diesel shop, or the parts stores.

[rover215]

elibenson: Thanks for the info! You've probably guessed I am not familiar with these models- I'm more of a VW TD guy, but I love diesels and have driven a turbo PSD and loved it. Wouldn't mind having a good, big van if the powertrain is sound.
Anyways, my friend is even less knowledgeable about his van than I am. He said it was "prone to vapor lock" but it sounds like you know better. Can I just bleed the air off? I'm hoping it's something I can do with a few simple tools. If I need to replace lines, again- I hope it's just time consuming and not too difficult. I have been tinkering with cars, trucks, and motorcycles for years (even replaced and engine and transmission successfully!) but I would still not say I'm a mechanic. I have lots to learn.
Sounds like the replacement of fuel return lines and their washers, o-rings, and clamps is money well spent.
I haven't heard back from my buddy yet but I'll post an update when I do. Thanks again-

Matt

btw, are these pretty solid motors if maintained?

[elibenson]

Originally Posted by rover215

elibenson: Thanks for the info! You've probably guessed I am not familiar with these models- I'm more of a VW TD guy, but I love diesels and have driven a turbo PSD and loved it. Wouldn't mind having a good, big van if the powertrain is sound.
Anyways, my friend is even less knowledgeable about his van than I am. He said it was "prone to vapor lock" but it sounds like you know better. Can I just bleed the air off? I'm hoping it's something I can do with a few simple tools. If I need to replace lines, again- I hope it's just time consuming and not too difficult. I have been tinkering with cars, trucks, and motorcycles for years (even replaced and engine and transmission successfully!) but I would still not say I'm a mechanic. I have lots to learn.
Sounds like the replacement of fuel return lines and their washers, o-rings, and clamps is money well spent.
I haven't heard back from my buddy yet but I'll post an update when I do. Thanks again-

Matt

btw, are these pretty solid motors if maintained?

The old IDI (In-Direct Injection) engines are quite long lived. I have one that is at 239,000 miles and it runs better than some of the others that I have.

The o-rings I told you about will cause the truck to be hard to start due to the air in the fuel system. It will take a little cranking to get it going. It doesn't really cause a problem once you get the engine warmed up though. They are not hard to change. If you pull the "dog house" (engine cowling) off the van you'll see the air cleaner. Pull the air cleaner off too. That will let you get access to the entire top of the engine. The high pressure fuel lines that go to the injectors will need to be taken loose while you are changing the o-rings and plastic "T" fittings. I would suggest you only take one off at a time. Keep them as clean as possible while you have them off. I blast them with Brake Clean before I start working on them. One of the injectors, I think it is the "#4" (driver's side second from the front) has a fitting that also has to be removed and replaced when you are done. It is for a timing device that you don't have.

All of this is pretty easy. All you have to do is make sure you put it back the way you took it apart. There is not special tricks here. While you have the air cleaner off, check for other fuel leaks on top of the engine. Check the oil for fuel in the oil (oil being overfull). These trucks have a mechanical fuel pump sort of like an old chevy. If it is worn out, it might cause the symptom you mentioned. More importantly it might cause fuel to leak into your oil through a bad diaphragm if it it is worn out.. While you are working inside the truck, you might as well replace the fuel filter. There is a cap that goes on the bottom of the filter to make a water drain and "water in fuel" light. The thing is notorious for wearing out (it's nearly 20 years old, it lasted pretty long). Ford doesn't offer any replacement parts for it any more. If the drain is leaking, you will probably just have to epoxy it up and change the filter if the "water in fuel" light comes on. That is what I had to do with my 2 Ford IDI trucks.