Bought this old 88 ford 7.3 diesel truck have trouble trying to start.

She is a mess. fuel lines are butchered someone did a shoddy job.
anyway i put new starter in and 2 new 1000amp batteries. Cranking her over she doesn't seem to turn as fast as my running 7.3 idi truck. I switched startrers to test them and same thing. My running truck turns over really quick. The bad one turns over slower. Can air in fuel system cause truck to turn over slow because batteries and starter and cables are new.

Anyway i pushed in the shrader vALVE and a **** load of air and fuel was bubbling out. I opened up the injector lines and same thing. I jumped the solenoind and the advANCE terminals. I sprayed either but all it would do it make the engine lock up and strain the starter.

Question is the fuel filter bled through the schrader valve??

Does air in system make it hard for engine to crank over??

The lines are mangled so i'm going to stick the fuel supply line and return line into a fuel can to see if i can get it running. Will that work??

The copper return and supply lines have rubber bushings on them. How do i tell if they are leaking and where can i buy them??

One injector seems to be spitting compression out of it with line loose, is that normal??


I'm getting frustrated here. Please help!!

 

For the slow cranking, follow all the heavy battery cables and feel for hot connections. Is there any corrosion on any of the cennections?

Don't use either. These engines will fire up very well even with things not working perfectly, but either more than likely to cause internal damage (cracked rings are common). If you still insist on using it than use it VERY sparingly, just a quick pop from the can and wait for the result. Too much and it will ignite before the piston reaches TDC. I will never allow either anywhere near any of my trucks.

Yes the shrader valve on the fuel filter will bleed air out of the filter if you have it open when the engine is cranking. You are on the right track here, keep bleeding until fuel comes out, then move on to the injector lines.

Breaking the torque on the injector lines will help to purge air out of the injection system more quickly. Again, you are doing well here, bleed all the lines and close them off once all are squirting fuel and it should start. When cranking, push the pedal to the floor, this will push the fuel flow and pressure up and help purge the air more quickly.

Air in the fuel system will not affect cranking speed.

You can bypass the fuel tank with a can of fuel if you want. It should work as long as it is placed before the lift pump on the side of the engine.

Compression shooting out of the injector is not good or normal. If thats indeed what is happening (and not fuel/air from the injector line shooting out), you will have to replace that injector before trying to run it.

 

ok i was using ether because truck need to be redone totally. glow plug wires need to be redone. Basically right now the truck is just a stand for the engine. im totally working under the hood. using a remote starter button. The spring for the throttle is disconnected i have throttle wide open. I jump solenoid with alligator clip to battery.

Is the fuel coming out of injector supposed to be squirting fuel or fuel and air? Right now it kind of bubbles fuel . When i press the shrader valve in it also bubbles fuel. i'm going to route the lines into the jar so i know there are no leaks. Right now somone has the stock plastic line cut and some kind of barbed coupling trying to couple the stock plastic to a rubber fuel hose to the rear tank. front tank is disconnected. the return line they coupled it just by inserting plastic line into rubber line with band clamps that aren't even tight. It's a mess. I'm going to get some clear line and do the return line thing i read about here. Maybe i'll put a clear line of the supply from filter to pump also.

I'll be post back with my findings.

My other one i bought recently need work on the glow plug circuit also. It won't start on its own no matter how hot it is outside but just a whisper of etther sprayed at the intake not even in it starts her right up. Go figure.

 

Hello. Well i took that spitting injector out. seems there is no copper washer gasket. I wonder how that happened. Also the metal on the tip was worn where the pintle comes out. I have a spare 6.9 engine in the garage. i took the injector out and i noticed the pintle pin sticks out a bit on that one. on the worn 7.3 the pintle pin is flush with the tip. Also the 7.3 injector is stanadyne the 6.9 is Cav. the 7.3 tip nut is knurled then 6.9 looks like a regular square nut. The 6.9 tip is shiny and look like may have been replaced .

I wonder if i should pull all the injectors. Are the copper washers reusable??

 

Copper washers should not be reused but I've gotten away with it on ocasion. If you are in a pinch they can be reused, but heating them up to cherry red will soften them so that they make a better seal. Just make sure the seal isn't in the injector bore.

 

I had the same problem with my starter for a year years. I kept changing battery wires cause the kept getting to hot and starters ... found out my groung circut was not complete. one wire was grounded to the AC bracket not the block . found the old wire still connected to the block and she spins wildly now.
My 6.9 will not crank with air in the injector lines. After running out of fuel a few times i have found just filling the filter up then bleading the injector lines in the fireing order on the intake it will crank pretty quick. then i go back over them and crack them one more time while its running.
My glowplugs dont work and ive been using starter fluid for several years. I do not recomend the Pyrol brand one squirt makes my engine clatter and 3 squirts locks my engine but the johnson's brand does not cause these problems( unless too much is used. maybe cause it atomizes it better.