IDI only happy when it's working

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Feb 11, 2016 | 02:21 AM

mebe2k

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Laughing Gas

Joined: Dec 2003

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From: Ford, WA

IDI only happy when it's working

I had to take my truck to a storage facility yesterday. I am moving and I needed a safe place to keep the 86 IDI and my 77 19.5' wellcraft boat (around 4k lbs. with junk and trailer) until i'm ready to drive it up to my new place.. The engine in the truck is worn, smokes horribly, and it HATES the freeway.. seems like every time I take her on the freeway, she breaks something, blows a hose, overheats or does some other stupid thing, but for some reason when she was pulling the boat she seemed like she was enjoying it.. she went on the freeway without one hiccup or complaint, I even had her to 70 and she seemed like she still had a little more..60-65 MPH seemed to be where she was most happy. It almost felt like it was a different engine...I've never heard it run so good... usually making a worn out engine pull/work makes it run worse..i guess IDI's are the opposite..

I just hope she will make the drive from Phoenix, AZ to Ford, WA (about 1300 miles) without any problems...once I get settled in I will be able to swap in the fresh 6.9L that I have and then I can rebuild the worn out engine that is in the truck now and keep it as an extra just in case.

Feb 11, 2016 | 09:21 AM

junkkingranch

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Joined: Apr 2013

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From: Paullina IA

They are funny like that. My 93 burned a gallon of oil to 100 miles. But it easily pulled a trailer and car to Chicago and back. That was 8 hours each way. I did replace the engine with a good running engine. Still haven't torn apart the old engine.

Good luck on the move. Keep the fluids full and I bet she does fine.

Feb 11, 2016 | 11:26 AM

Pkupman82

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Joined: Feb 2003

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From: Muskegon, MI (home)

Yeah I could say mine (84 F250 4x4 6.9/C6) was like that too. I'm doing a full rebuild on it at the moment. I've had it for 8 years now, and all its ever known is work. Plowing snow and towing 8-10k lbs. I show it no mercy, hammer down everywhere. When I tore the engine down. The bottom end was mint, but it had no valves left. It was getting tired and using ridiculous amounts of oil. It never gave up though, gotta love an IDI!

Feb 11, 2016 | 01:26 PM

mebe2k

Thread Starter

Laughing Gas

Joined: Dec 2003

Posts: 1,062

Likes: 12

From: Ford, WA

Quote:

Originally Posted by junkkingranch

Good luck on the move. Keep the fluids full and I bet she does fine.

Thank You.. I figured I would give her an oil change, and bring along a couple gallons of oil just in case.. I also found out that her CDR valve is shot.. the rubber diaphragm is completely gone..probably the reason for the excess oil consumption.. I tried running a road draft tube but it was well.. bad... looked like the truck was on fire when I was sitting at red lights.. infact, one car actually backed up because they didn't want to sit next to my truck

the exhaust still smoked even with the RD tube.. so I just put the CDR back in.

I really hate moving.. you always ending up having more crap that what you thought you had..

I'll be glad when it's over, so I can get back to wrenching on my trucks.. I have a nice shop to work on them in now..my garage in Arizona is too small for me to work on anything in..

Feb 11, 2016 | 01:43 PM

Pkupman82

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From: Muskegon, MI (home)

As long as you have air and fuel, these things will run indefinitely. Oil in the crankcase helps, a little oil pressure never hurts either!

Feb 11, 2016 | 02:25 PM

mebe2k

Thread Starter

Laughing Gas

Joined: Dec 2003

Posts: 1,062

Likes: 12

From: Ford, WA

Quote:

Originally Posted by Pkupman82

As long as you have air and fuel, these things will run indefinitely. Oil in the crankcase helps, a little oil pressure never hurts either!

I had a 70's 460 with a broken piston make it all the way from North Dakota to Arizona, and then back again..got so bad towards the end that I had to feed it a quart of oil every 80 miles.. yes.. every 80 miles..where it was going I don't know, it didnt smoke or leak.. It did run low enough to make the lifters start tapping a few times, but that engine kept going..still ran when I junked it(the engine), and it started first try every time..

Feb 11, 2016 | 08:29 PM

Macrobb

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Joined: Dec 2011

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Quote:

Originally Posted by mebe2k

It almost felt like it was a different engine...I've never heard it run so good... usually making a worn out engine pull/work makes it run worse..i guess IDI's are the opposite..

All of my IDIs are this way. They tend to be happiest under a heavy load.

I suspect there is a good reason for this -- under a heavy load, you are pouring more fuel in, so variations in pop pressure will matter less(these variations will change the start of the injection timing).
Also, it will effectively retard the engine more than the same speed unloaded, due to how far the pedal is down and the pressure differential inside the pump.
In addition, you are heating things up, so the pistons and rings should become tighter, resulting in less blowby and more power I think. Also it probably helps to burn out carbon deposits that may be getting in the way of things.