Attempting to resurrect an old IDI. HELP PLEASE!

[NCTractor6.9]

Hello all,

First off, this is my first post. I'm a normal garage mechanic with some experience on rebuilding gas motors but this is my first diesel. So now the story..

I bought my 1984 F250 6.9IDI back in early October. She was lost and forgotten in a field about an hour away from where I live in Raleigh. PO stated he believed she had a blown head gasket about a year ago when he parked her and left it. Asking $1100 I loaded her on the trailer and brought her back for $600. It's a manual, regular cab, long bed with probably fifteen shades of white covering the body.

We completed a head gasket change per some notes I found after HOURS of research on the internet. She got a valve job as well as new glow plugs when we put the new head gaskets on. Note: What a job getting those heads off without a lift or pulley system...

New fuel filter and new oil filter with fresh oil and she refuses to start. We have attempted for hours to purge the air out of the fuel lines, from the schrader valve and by cracking each injector line while turning the motor over. We even rigged up a separate fuel line bypassing everything before the mechanical lift pump on the side of the motor. We did this thinking that the stock fuel/water separator could be allowing air into the system, that was yesterday and it did not make a difference. I've put a new "Ultima Select" starter in there, that seemed to help a little by turning the motor a little faster than the stock starter we took out. New starter relay. The glow plugs are controlled by a push button inside the cab.

The motor does seem to hit on one or two cylinders from time to time, usually with a small shot of ether, but I've read to limit my use of that.

Any help from here would be greatly appreciated. I would love to put this truck back on the road as the interior is in really good shape and you don't see many of the trucks around anymore.

Cheers

 

[Hydro-idi]

You will need to crack open all injector lines at the same time and crank engine until you see each injector cap wet. Close them and attempt to start. Repeat process until she fires. If you have weak batteries, engine will not start period. These engines require lots of starter speed & fully charged batteries to fire off.
Did you replace fuel filter? If so, it needs to be completely filled with diesel or fuel conditioner of choice which will aid in priming system.

 

[crash-harris]

Have to checked to be sure the lift pump is actually moving fuel? Does your new oil smell like diesel already?

Hydro, he stated new oil and fuel filter ;p

 

[IDIoit]

not only new batteries, and new starter.. but new cables also.
its not a big deal in gassers, but in diesels, you better believe it!!!


what about your glow plug controller?


another safer way to help start is to put a rosebud on your torch.
warm up the air in the intake.

also you could try pull starting it.

 

[Waystro]

First check to see if your getting fuel to injector pump
If not your Lift pump could be dead or fuel line clogged.
I have a newish Lift pump from my first truck that you can have if you need it. Just pay shipping.

 

[icanfixall]

Welcome to the forum. My best question to ask is when you removed the injection pump did you remove the pump still attached to the housing and gear? If so by bet is the injection pump gear is not aligned correctly.
As for new glow plugs, what type did you install? Sadly there are some horrible glow plugs like champion or autolites that will not work long and swell when they fail. Please do not use them. As for leaving hard line loose at each injector I suggest not to. Reason for keeping them tight is you crank for maybe 10 seconds and then crack loose each one looking and listening for air and fuel to escape. You can hear the hiss of air escaping plus this tells you the pump is making pressure. As for knowing if fuel actually is getting to the filter you might want to check closer about that too. Then remove the top return line from the injection pump and while cranking you should see fuel coming out of that line.

 

[riotwarrior]

I am guessing its either a timing gear issue or ip is toast a d it wasnt a hg issue ...

More details and we can provide more accurqte diagnosis.

 

[JLtoolman]

Hello, I am a new to the forum, also.

Good to hear of another one getting back on the road. Looks like we are close to each other.

I have some experience starting diesel engines that have run out of fuel. Let me know if I can help.

 

[NCTractor6.9]

Hi all,

Thanks for the replies. I'll add a few more details; 1) I know the IP is working and producing at least some amount of pressure because when I cracked each injection line at the injector (as stated in my first post) I did get some fuel coming out of the lines, just not sure if the pressure is enough, it was a mere drip coming out of the line. 2) when I removed the IP when replacing the head gasket, I did NOT remove the housing, but just the IP and all the metal lines that attach to it and each injector. 3) I am using new batteries (as well as that new starter I mentioned) but the battery cable ends (which attach straight to the terminal) are in pretty dismal shape, I will be replacing those today as we focus again on trying to get the truck started. 4) I assume I am not using a glow plug controller since I am putting fire on the glow plugs by a switch inside the cab.

With that, I would like a little clarification from you guys as you have already been very helpful. I can safely assume that my lift pump is working correctly and my IP is at least making some pressure and pushing some fuel through the injectors. Should I be taking loose each injector at a time today when I attempt to purge the air from the injectors? Or should I take ALL of them loose at the same time while trying to start it? We have done the procedure 3 times now loosening one injector at a time with negligible results at best...

Thanks in advance!

 

[Hydro-idi]

Loosen all 8 injector lines at the same time to properly bleed out the air.

 

[OLDBULL8]

Crack all of the injector line nuts, DO NOT remove the lines.

Crank until fuel shows at the line nut, then tighten that nut, repeat until all lines show fuel. All air should be removed from IP to injectors then.
If it don't start and keep running, then you have air intrusion someplace in the line from tank to lift pump.
Loosen the valve in the Schrader valve, crank, should have a full stream of fuel, if lots of air spurts out, then sentence above.

 

[riotwarrior]

Are the gp working?

Can you plug in bloco heqter or use magetic heaters?

When u remove lines from injectors to get air out and crqnk....hold throttle wide open to move more fuel through lines.

Thinking gp n heat should work...

 

[IDIoit]

DEPRESS the valve in the Schrader valve, crank, should have a full stream of fuel, if lots of air spurts out, then sentence above.

wouldnt want him taking the core out..

 

[NCTractor6.9]

I'm going to try this morning loosening all the injectors as you guys suggested. Will post results later this afternoon hopefully.

Thanks guys

 

[icanfixall]

You can bleed the air from the system by cracking lines loose at the injectors & cranking for no more than 15 seconds and then waiting 2 minutes for the starter to cool down. Of crank for 15 seconds with the lines tight at the injectors. Then loosen them and watch and loosen for air escaping. You do not need every injector flowing fuel for the engine to start. If you have the easy to reach injectors on each side that will get the engine running. At least 3 well bled injectors will fir off the engine. Then the others will clean up as the engine runs.
You wont see lots of fuel at the loose injector line. These diesels burn very little fuel at idle speeds. The most you will see is a small drop of fuel. Now what will make you feel something is wrong is when the fuel finally is pressurized to say 1850 lbs only then will you see fuel squirting out of a loose fitting. Remember its only pressure with a very low volume of fuel. Also be careful not to allow the high pressure fuel touch your hand. It WIL get injected under the skin and cause all kinds of trouble.