But the car pulls beautifully! Wouldn't a bad head gasket cause very poor performance?

Stretch gives a great suggestion, a leak down with compression on warm engine. At least you'll have more data to suggest engine health.

Smoking IS poor performance. It might pull fine, or it feels that way, but if you compared it to a healthy (IE non-smoking) engine, you'd know it's not all there.

Smoke, especially white, blue or grey smoke indicates something is not well. Figuring out what that "something" is is your challenge.

Head/head gasket problems with these old cast iron engines are not common.

I disagree
 

At this point, failing 30+ year old head gaskets are fairly common.

Continuing to drive with a failing 30+ year old head gasket = BEGGING for further damage/destruction.

http://www.peachparts.com/shopforum/diesel-discussion/325016-1980-240d-cracked-cylinder-head-cavitation-damage.html

Replacing the head gasket is not difficult, as many members know.

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Hmm
 

I agree wit this statement:

Smoking IS poor performance. It might pull fine, or it feels that way, but if you compared it to a healthy (IE non-smoking) engine, you'd know it's not all there.

Smoke, especially white, blue or grey smoke indicates something is not well. Figuring out what that "something" is is your challenge.

.

I can compare it to my 617 300sd which pulls pretty similar. How long do you think it would take to pull the head and replace the headgasket and do you think a 16 year old would be up for it? What DIY rating would you guys give this job? haha

Hmm
 

Here is a thread from a 16 year old...
http://www.peachparts.com/shopforum/diesel-discussion/104222-wont-start-anything-1985-300sd.html

Average skill, average time, average tools set, working alone = two days, start to finish.


http://www.peachparts.com/shopforum/diesel-discussion/335318-om61x-cylinder-head-hidden-bolts-did-you-miss-them.html

http://www.peachparts.com/shopforum/diesel-discussion/335306-have-you-replaced-one-more-diesel-cylinder-head-gasket-how-long-did-take.html

http://www.peachparts.com/shopforum/diesel-discussion/335305-cracked-cylinder-head-diy-cost.html


You may want to read this thread, it took him serious cleaning to find these cracks on a single cylinder. Post# 12 of this thread has further examples of what you may find.
http://www.peachparts.com/shopforum/diesel-discussion/332787-300d-overheated-blown-head-gasket-what-do.html#post3112778

This entire thread will interest you, but post #44 and #49 show another example of cracks on one cylinder. Post# 144 details the cleaning used to find the cracks.
1985 300TD head gasket repair
http://www.peachparts.com/shopforum/diesel-discussion/325433-1985-300td-head-gasket-repair.html


http://www.peachparts.com/shopforum/video-forum/346092-diesel-vehicle-technical-diy-video.html

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Could messing with the screw and nut on the injection pump affect anything and cause my problem?

Generally speaking random messing with stuff isn't the smartest thing to do...

...however it usually presents the opportunity to learn.


(Did I say opportunity? I think I meant necessity.)

Yes, and these kinds of details are critical when you're asking for advice in a forum.

I just remebered about it. I would have mentioned something but I completely forgot until yesterday. Earlier, I messed with the nut, but the screw wouldn't turn when I held it with a screw driver, one piece broke off of the side of the thread that is sticking out. I got scared and just tightened the nut back up. But, when I loosen the nut and turn it with the engine running, the idle is the same and it seems like it doesn't affect anything.

I have no idea what might have happened there David, we'll have to wait for whunter or someone else to reply. But, this adds a lot potentially, since I theorize something is wrong with fuel delivery with the way you're engine is running.

You've double checked and triple checked the valve lashes. (I did that too, and was shocked to find 2 intakes were tight again, and had to be readjusted).

Do you think my injection pump could be just putting out too much fuel, and the smoking is the unburnt fuel?

Which screw and nut? ALDA? No. Any others, yes.

Yes, it was the ALDA. Sorry for the sucky quality.
Attachment 116680