dt466 (older model) tuneup questions - Diesel Truck Forum - TheDieselGarage.com
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post #1 of 4 (permalink) Old 05-28-2009, 04:17 AM Thread Starter
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dt466 (older model) tuneup questions

I'm getting ready to do some traveling in my 1977 skoolie bus. It has a DT466 and I want to tune it up good before I go. It doesn't seem to have quite the power it used to. Please forgive me any stupid questions - I am still a bit new to diesel engines. I knew I wanted an International when I got the bus, and only later found out what a great find it was! On to my questions:

1. I believe it should have a valve adjustment. I got the service manual off of ebay and the procedure looks simple, but is there anything special I need to know?

2. It has the rotary injection pump, and it seems to be leaking fuel from where one or two of the injector lines goes into the pump - there is fuel sprayed everywhere around there but I cleaned it off good and that's where it seems to be coming from. I can't get a wrench in there very easily. Is there a special tool I need? Would it likely help to remove and reinstall the injector lines? Do I need new seals of some kind? Anything else I need to know there?

3. Can I test the injectors myself, or would it be cheaper to have it done? It blows a bit of gray smoke so I'm afraid they're dirty. Is there a simple way to clean them?

4. I think the only other thing it needs is a new secondary fuel filter (just replaced the primary on the road last weekend); is there anything else I should check/adjust/replace?

Thanks in advance for any info and advice. I have learned quite a bit of useful information from these forums already - this site is great!
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post #2 of 4 (permalink) Old 06-01-2009, 06:45 PM
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the leaking at the pump could be the injector line or the adapter they attach to there are no seals on these just snug them up if snugging the line doesnt stop the leak loosen the line and tighten the adapter. these sometimes loosen when cracking the lines to bleed the engine or what not, most i have seen are just pipe thread at the pump and the injector flare on the other end.

changing the fuel filter and running some good fuel treatment should help also check the air filter it could be causing some of your excess smoke.

usually a bad injector will cause a miss sometimes at idle and usually at a higher rpm or under load if you are only getting a little ugly smoke check the air filter and make sure there is no water in the fuel get some good additive and run with it.
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post #3 of 4 (permalink) Old 06-01-2009, 06:49 PM
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oh yeah a valve adjustment is simple to do just pay attention and if you have a manual you've got it made.

i got my start running overhead on 3406 cats when i was a kid my dad hired a guy to come out and do 1 truck and i said i can do that the mechanic told me to get with it.
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post #4 of 4 (permalink) Old 07-21-2009, 07:42 AM Thread Starter
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Thanks for the advice. The valve adjustment was indeed easy and WAAAAAY overdue! The specs call for .020" intake and .025" exhaust, and I had over .070" of feeler guages in one of them with room for more - but I really couldn't handle knowing any more than that! Had some trouble getting the valve cover back on until I remembered what I had read on the forums and got the inside lip lined up (with the help of some clamps). It runs so much better - turbo kicks in 200 RPM sooner which really helps on the hills - I even upshifted going uphill a few times, which was previously impossible with my way-too-wide gear ratios. The engine is also much quieter - I've even gotten comments on how quiet it is for a diesel!

The injectors seem like they finally cleaned themselves somehow since power is up & smoke is down after about 2000 - 3000 miles of driving. The fuel leak is much better, but may not quite be gone. I'm sure I'll get it fixed completely when I finally get the injectors out for proper testing.
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