First Diesel Ever, Could Really Use Some Advice

First time on this site, I apologize for any formatting, etiquette, or vocabulary related shortcomings. I did consult the Tech Articles and FAQs before posting.

This website seems like the perfect place for a know-nothing 18 year old to gather some wisdom, so here it is: I bought my first diesel last Saturday, a 1989 F250XLT with a 7.3IDIT out of a 1994. I thought I had been pretty thorough with my inspection and questions before purchasing, but now I’m really feeling the sting of knowing very little about diesels. I know of the IDIs as being very reliable engines, and I’d like to be able to maintain one to the best of my ability, but it looks like I’m going to need my hand held through the learning process. There are a multitude of problems and concerns I am encountering, but I don’t want to gum up this thread with my issues. If I had another resource for IDI knowledge, I’d use it, but BFE Iowa is sparse with IDI mechanics. If there is a better place to direct these issues and questions, please let me know. If this is the right place, then I’ve got a handful of issues and I’d love to get some answers/advice.

You're definitely in the right place, no better place on the net for IDI questions! Ask away and Welcome to Oilburners! Congrats on your new truck too!

Thank you for the warm welcome! Glad I came to the right place. Now for the issues: I’ll start off with excessive blow by. I have no clue how to gauge blow by on these engines and I do not have testing tools available to me. When warmed up, the blow by from the oil fill cap looks like a tea kettle and whistles as well. There is also blow by coming out of the dipstick. If the dipstick is removed while idling, specs of oil coming out of the dipstick will pepper its surroundings. All this occurs while there is another strong stream coming from the RDT. I have heard some say this is just high miles, and others attributing it to cracked pistons, stuck rings, or a cracked header. With that much blow by, I would assume it would have trouble starting, but it seems to start well and have reasonable power while operating. If I can determine if the engine is junk or not, then I can go on and decide whether or not to invest more money in it or search for a new engine. The previous owners had added a Holley fuel pump and the RDT, and most startups are marked by white smoke. This, and the fact that it rolls serious coal in certain gear ranges makes me thing the fuel is too high. If I knew how to adjust fuel and timing I would love to see how this may be affecting my blow by. I would also like to put the CDR back on. The engine has in the neighborhood of 160k miles on it, and the puke coming out of the draft tube is getting redundant. There’s more issues but I think this is a healthy bit to digest for now.

If you did put the CDR back in place, it would help the blow-by situation. If all you have is a road draft breather setup, you will get a lot of pressure in the crankcase. Most gas engines run the PCV system on their crankcases, so you don't see this unless they are really worn out. But if you disconnected the PCV system on a gas engine, you would see the same thing you are seeing on your engine.

Problem is, you need to move the CDR system to in front of the turbo, it can't be plumbed into the back of the intake like it was originally, that is now under pressure from the turbo.

From what I understand of the schematics of the factory turbos, it looks like the CDR was originally mounted to the driver side valve cover, or at least that’s where its brackets are on mine. Coupling age with the RDT (which I don’t think has the right circumference of hose), would that account for the oil being pushed out of the dipstick?

Welcome to the Oilburners website. It is beyond a doubt the best source of information about these old IDI trucks. The fact is that we have more and better information than almost all Ford dealers. The dealers look at our trucks as antiques, and don't want to be bothered. Their mechanics don't know much about our trucks, and have no interest in learning. Our members, most of them, have learned how to work on their trucks out of a sense of survival and because they enjoy it. Unlike so many forums, we're a friendly group. We're no going to jump on you for asking a newbie question. At worst some one will suggest a search of the forum if your question has been answered too many times.

I do have a suggestion. Now that you've given us a rundown on the truck and it's condition, ask fairly specific questions, one subject area per post. As an example, "I think the previous owner turned the fuel up. How do I turn the fuel down?" You're more likely to get specific answers.

Also, try to work on, adjust, one thing at a time. That way you'll know why something has changed as a result. If you do three different things in different areas, you may not know which caused the resulting change.

If you're not sure of a procedure, ask. As simple as these engine are, it's still not too terribly hard to screw them up.

It would be really helpful to order the Ford IDIT service manual off of e-bay . provides a lot of useful information.

Zion said:

This website seems like the perfect place for a know-nothing 18 year old to gather some wisdom, so here it is: I bought my first diesel last Saturday, a 1989 F250XLT with a 7.3IDIT out of a 1994.

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Hold on just one minute. At least you know enough to buy a Ford with a IDI in it. That counts for something right there!

Zion said:

BFE Iowa is sparse with IDI mechanics.

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Unfortunately, these days, most are IDI "mechanics". The difference being that they only think that they know something about these engines. It's all over too. You'll find out that there is a lot of people who don't know the difference between a 7.3 IDI and a 7.3 PSD. Most of those don't even know that there was two diesel engines with the same displacement.

Zion said:

When warmed up, the blow by from the oil fill cap looks like a tea kettle and whistles as well.

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These engines have rather large gaps between the ends of the rings when installed. This does make for a lot of blow by. You're probably not hearing a whistle with the oil cap pulled when the engine's running. These have gears to drive everything at the front of the engine: oil pump, crankshaft, cam shaft, and the injector pump. The IP gear is right underneath the housing that has the oil fill cap on it. It makes a lot of noise with the cap off and the engine running. This is probably what you're hearing. If you want to check this out, while the engine's running, remove the oil dipstick and listen for a whistle. I'll bet that you won't hear one.

Zion said:

most startups are marked by white smoke. This, and the fact that it rolls serious coal in certain gear ranges makes me thing the fuel is too high.

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This makes me think that the timing is a little slow. In order to advance the timing, with the engine off, you loosen the three nuts that hold the IP and rotate the top of the IP toward the passenger's side. I always hold the IP with something to keep it from moving on it's own. I'll loosen the top nuts last and tighten it first since it's the easiest to get to. The lower nut on the passenger's side is a PITA to get to, just so you've been warned.

Zion said:

would that account for the oil being pushed out of the dipstick?

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Quite possibly.

Heeding good advice, I’ll limit this post to the subject of blow-by. I took a video tonight of my trifecta of smokestacks under the hood, but was cut short by the alternator deciding to pass away. How does one go about adding a video to a thread? I feel it would be beneficial to add some imagery to my descriptions.

Zion said:

Heeding good advice, I’ll limit this post to the subject of blow-by. I took a video tonight of my trifecta of smokestacks under the hood, but was cut short by the alternator deciding to pass away. How does one go about adding a video to a thread? I feel it would be beneficial to add some imagery to my descriptions.

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Just upload to youtube and link it here. Easiest way.

Alternater took a dump? Time for the 3g swap! Lol. I just recently jumped into that bandwagon so super impressed still. I think putting on the cdr will help with alot. I also agree with @IDIBRONCO on the ip timing. The turbo should be cleaning a good bit of that coal up. Maybe adjust the wastegate a bit as well. But as mentioned, one thing at a time. Get to know your rig a bit while your in there and doing your test runs between each tweek or adjustment you make.

“Rolls serious coal in certain gear ranges”

below about 1500 rpm, that is normal under moderate acceleration, even unloaded

frankenwrench said:

I just recently jumped into that bandwagon so super impressed still.

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Same for me.

frankenwrench said:

I think putting on the cdr will help with alot.

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I completely agree with this. There is a reason why it was put there in the first place.

frankenwrench said:

The turbo should be cleaning a good bit of that coal up.

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This and the white smoke at start up part are why I suggested timing before trying to adjust the fuel.

In regards to the CDR do you have a hole in the drivers side valve cover , as that is where it belongs if you have a turbo engine.

I believe the media I embedded will work, but it gives visuals to my blow by issues. I’ve written out a list of what I should adjust from this thread, and I plan to work through it before making another questions thread. I really do appreciate the help from everyone, I’ve been looking to get my hands on an IDI since I was 14 and now that I finally have one, I intend to maintain it as best as possible. If the video unveils any other comments or concerns, please let me know so I can add it to my list.