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1986 6.9 won't start ?

  
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1986 6.9 won't start ?

 
c4f5 c4f5
New User | Posts: 3 | Joined: 03/11
Posted: 03/18/11
09:14 AM

This is my first diesel. i work on gassers regularly, but I am no diesel mechanic by any means, but can't afford to hire it done, so it's time to learn. Bought it not running. Mechanical fuel pump was bad. replaced it. Primed it. I know I'm getting fuel to the injectors now, as 5 of the 8 leak. I know all 8 glow plugs are gone. The previous owner set up a tube from the cab to the breather for ether. He let somebody else use it. That's when the fuel pump went out. Appearantly that's not all that went, as it won't start now....not even with either. Cranks fine & sounds normal cranking. Has a sparatic rattle like it wants to take off, but nothing more. Even plugged in the block heater for a day first. The engine was warm to the touch...maybe 110 degrees. Please help.

If all else fails, I will convert it to gas. Anybody know if the 6.9 matches any gasser bell housings, so I can still keep the 6.9 transmission? Thanks.  

tdbt3c tdbt3c
User | Posts: 200 | Joined: 09/08
Posted: 04/04/11
09:58 AM

Convert it to gas!!? That's blasphemy on here! Just kidding.

OK, so you know the glow plugs are bad, but if you're plugged in that should be OK. As long as you are using ether, don't use the glow plugs, as it can cause premature ignition and do some damage.

You know that 5 of 8 injectors are leaking. Replace them. Diesel engines need that proper atomization of the fuel to get good ignition. Injectors are not too bad, I think about $25 a piece for new ones.

You say you have changed the injection pump. Did you make sure it was all timed correctly when you put the new one on? I knocked mine out of time, and it took a week worth of taking it apart and putting it together every day for a week before I finally figured it out. In the end I was 180 degrees out of time, so the engine would start (with ether), and smoke like a train until it eventually died.

Last off is the chance that you have an air leak (God forbid). But don't give up hope. I probably have a dozen posts on here about tracking down air leaks on the old IDI's. Just know that with a diesel, all you need is fuel and air, and you should have combustion, assuming it is in the proper quantities.

If you need further help, let us know. Feel free to hit me up with a personal message and we can go from there on trouble-shooting. Chasing air leaks can be really depressing on these old trucks, but it's not impossible.  Laugh  
1988 F-250 7.3L w/Banks Sidewinder Turbo. Custom flat bed with hydraulic dump.

c4f5 c4f5
New User | Posts: 3 | Joined: 03/11
Posted: 04/04/11
05:57 PM

I didn't replace the injection pump, just the mechanical lift pump. And I believe it's just the seals leaking around the injectors. I have a new seal kit. Haven't installed it yet. I've kinda put it on the back burner for now, but need to put it back on top of the priority list soon. It has a nice wrecker bed on it. It has already sat for about 3 years now.  

tdbt3c tdbt3c
User | Posts: 200 | Joined: 09/08
Posted: 04/06/11
06:36 AM

That makes sense. I have replaced my lift pump before as well. But from my experience, I've had a lot more issues with the injector pump than the lift pump. Your quickest cheapest bet is to look for an air leak. Anywhere you have a rubber hose, you do not have high pressure. So you can swap the black rubber hose with clear rubber hose. Then crank the engine and look for air bubbles in the fuel lines. I was told to do this after almost a week of chasing an air leak under the hood, and when I finally did so, found the air actually coming from the sending unit on the fuel tank.

Good luck on replacing the seals. A set of small (jewelers) screwdrivers comes in really handy. Just be patient, and don't drop any seals, as they don't typically pack any extras.

Let us know if you need anything else. Good Luck!  
1988 F-250 7.3L w/Banks Sidewinder Turbo. Custom flat bed with hydraulic dump.

c4f5 c4f5
New User | Posts: 3 | Joined: 03/11
Posted: 04/06/11
07:44 PM

Thanks for the tips. I got the complete set of seals. I will be sure to change the leaky ones first, just in case I lose one or kill one.

Even with all of this, shouldn't the pre-heated engine fire on ether?  

snc22782 snc22782
New User | Posts: 1 | Joined: 01/12
Posted: 01/16/12
10:20 AM

Did you figure this out? Mine will not start on ether either.  

knight11 knight11
New User | Posts: 2 | Joined: 01/12
Posted: 01/16/12
01:34 PM

Does anyone know if the 6.9 have a computer in them Confused  

acline acline
New User | Posts: 4 | Joined: 02/12
Posted: 02/19/12
10:24 AM

ya and if your glow plugs are gone then you need to replace them because the 6.9's are cold blooded *** and it wont start in 120 degree wether without them  but those motors are bullet proof just sold one with over a million miles because the body was toast but the motor was still a champ and the whole odometer was just rolling over haha  

Simpleman863 Simpleman863
New User | Posts: 1 | Joined: 07/12
Posted: 07/20/12
04:41 PM

My 6.9 for some reason keeps loosing prime at the lift pump I have to prime it every time I start it if it sits longer than an hour didn't start until I changed my glow plug and broke the fuel lines loose to put in a glow plug please help  

jason.thompson jason.thompson
Guru | Posts: 839 | Joined: 06/08
Posted: 07/20/12
05:11 PM

Replace the injector fuel lines, plastic caps, and o-rings. It all comes in a kit.

If your truck is running bad the first thing to do is make sure it has fuel. A quick way to check is unscrew the fuel filter. If should make a sucking sound when you unscrew it and it should be totally full of fuel with no air space. If there is no fuel check the return lines from where you just replaced it past the bronze fitting at the back of the engine (that always leaks) and all the way to the tank.

No this engine does not have a computer. It does have a control box for the glow plugs.

Fuel timed right (upcoming article) + proper Compression done with a compression tester + Air (check air filer) = Running engine

I'd like more information on that million mile 6.9!  
___

My personal goals include developing perpetual motion and bringing power to the people. I’m also working on building a ’87 Ford F-250 7.3L IDI (Project 300) on a paycheck- to-paycheck budget. One day, I’d like it to be a renewable diesel-steam-hydraulic-compressed- air-wind-solar-infinitely-variable-transmission-equipped hybrid, but until then, I’m just happy to have a simple diesel-powered pickup.

jason.thompson@sorc.com

Powerstroke_Cowboy Powerstroke_Cowboy
User | Posts: 128 | Joined: 05/11
Posted: 07/21/12
07:48 PM

What do you have for compression???   Its not hard to check..  Most automotive places will have them or can order one for you....  
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97 Ford 7.3L F-350 (Under the knife)  On a side note... It is now running, Just a couple more odds and ends and it will be back on the road...
97 Case MX100 5.9 Cummins
81 Allis chalmer 7010 649T Allis chalmer diesel (Under the Knife)
75 Petrbuilt truck 350 Big Cam Cummins
06 Outlander 800 wish it had a TURBO
94 Ski-doo 670 long track.
07 Quarter Horse Gelding

GeeLee GeeLee
New User | Posts: 8 | Joined: 07/12
Posted: 07/23/12
12:18 AM

Haven't checked, but I know it is not good.  26 year old engine and I almost always have to use starting juice in cool weather.  Batteries are pretty new and drop to 10.6 volts on start.  Will check the compression and get back to you. Other projects have got in ahead of the line; like putting a new engine on my generator after losing it during the week power outage that we had here in SE Ohio. I still had two other generators to keep freezer and fridges going, plus the elixir of life... the coffee pot!

Thanks,

GeeLee  

GeeLee GeeLee
New User | Posts: 8 | Joined: 07/12
Posted: 07/23/12
12:25 AM

Icon Quotejason.thompson:
Replace the injector fuel lines, plastic caps, and o-rings. It all comes in a kit.

If your truck is running bad the first thing to do is make sure it has fuel. A quick way to check is unscrew the fuel filter. If should make a sucking sound when you unscrew it and it should be totally full of fuel with no air space. If there is no fuel check the return lines from where you just replaced it past the bronze fitting at the back of the engine (that always leaks) and all the way to the tank.

No this engine does not have a computer. It does have a control box for the glow plugs.

Fuel timed right (upcoming article) + proper Compression done with a compression tester + Air (check air filer) = Running engine

I'd like more information on that million mile 6.9!


Yes, I have dropped the fuel tank, fixed a couple of rust holes in the top of it; pressure tested the fuel line for leaks to the fuel pump; then replaced the fuel pump and filter; Bled all the lines and have good pressure to the fuel injector pump.  And to the injectors.  
I haven't replaced the injector fuel lines, but will do that; can't hurt!  I'll look to getting that kit.

I like what you said, :Fuel timed right (upcoming article) + proper Compression done with a compression tester + Air (check air filer) = Running engine"

It does have low compression and probably needs rings/overhaul... Batteries are good so I have high starting RPMs; voltage only drops to 10.6 under starting load.

ThanksGeeLee

>  

GeeLee GeeLee
New User | Posts: 8 | Joined: 07/12
Posted: 07/23/12
12:28 AM

Icon Quoteacline:
ya and if your glow plugs are gone then you need to replace them because the 6.9's are cold blooded *** and it wont start in 120 degree wether without them  but those motors are bullet proof just sold one with over a million miles because the body was toast but the motor was still a champ and the whole odometer was just rolling over haha

OK Good idea.  I'll check the glow plugs and see if they are getting some voltage to them and check the timer that runs them.

Thanks,
GeeLee  

GeeLee GeeLee
New User | Posts: 8 | Joined: 07/12
Posted: 07/23/12
12:32 AM

Icon QuoteSimpleman863:
My 6.9 for some reason keeps loosing prime at the lift pump I have to prime it every time I start it if it sits longer than an hour didn't start until I changed my glow plug and broke the fuel lines loose to put in a glow plug please help

Yep, replaced the pump and did a pressure check on the fuel line from tank to pump.  I also thought of an air leak in the fuel line... sounds like what you may have, just a little pin hole of a leak will let the fuel slowly leak back into the tank.  I've bled and replaced every thing from the pump to the injector pump and have pressure there... good pressure that will fill quart jar in a short time.

Thanks,
GeeLee  

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