B7500 fuel pressure?

[jaymee01]

I have a 2002 b7500 that won't start. A little history... it would on occasion, while driving it, it would bog down, low to no rpms,almost like it was running out of gas. This happened several times over a few months. It would always pick back up and run as normal, at least until it happened again. Then one day, sever months ago, I started it up and it ran as normal for 10 to15 seconds, then died. It hasn't started since. I replaced the glow plugs and still won't start. New battery since the old was, well old. I started tracing fuel and noticed only a trickle out of fuel pump. I just received a new pump and put it on and lots of fuel out of it now. Reinstalled the fuel line going to injector pump and still no start. I open one fuel line at the injector and only a small amount comes out. I did drain the fuel tank just in case I had bad fuel . Filled with fresh diesel. The book says to bleed the system, start it and let it run for 30 seconds but thats not happening now. What is the pressure at the injectors supposed to be? I would imagine more than a trickle. The fuel pump has plenty leaving it and going into the injector pump.

Ideas? I hate to buy an injector pump, if that isn't the problem.

Thanks for the help. Ask any thing I left out.

Jaymee

 

[mendonsy]

A couple of suggestions:
1) Check to make sure you have all of the air out of the fuel lines between the fuel filter and the injector pump.
2) Inspect the lines between the fuel filer and the injector pump for any minor leaks. It doesn't take much of a pinhole to get air into the injector pump.

 

[North Idaho Wolfman]

You need to crack all of the fuel lines right at the Injectors.
You crank it till you get good fuel without bubbles.
Then tighten the lines.

 

[Russell King]

While you are bleeding to the injectors, crank for 30-60 seconds and then let the starter cool for a couple of minute. Repeat a few times and then let the starter cool down completely so it is just warm to your touch.

When you think you are done do it at least one more time.

oh and set the throttle to full speed while bleeding it.

 

[jaymee01]

I will try the cracking all the lines and bleeding them, with the crank, and let started cool etc..thanks for the advice. I will let you know.

Interesting thing, I never had an empty tank until after this started. Maybe the fuel pump went bad and I have air in the system now? Hmm. I am hoping this is all it is!

Thank you!

 

[jaymee01]

Good morning. After lots of life getting in the way, I was able to go out and crack open the fuel lines at the injectors, and cranked it over, let it cool down, and do it again. I did this for about 30 minutes. Then waited another 30 minutes to let the starter completely cool down, and then do it all again for another 30 minutes. I am currently charging the battery again, since I ran it down some. The fuel coming out of the ends of the fuel lines, at the injectors, isn't much. Or at least, not what I expected it to be.

The engine started to sound as though it was trying to "hit" and maybe close to starting. Then it dawned on me. When I first bought this thing 7 years ago, I forgot to push in the stop lever and it seemed to have the same sound coming from the engine when cranking it. How does the stop lever function? I know it connects to some sort of valve right before the fuel pump and I presume it cuts the flow off to the pump when the lever is pulled out? How would I go about bypassing it? It would be a good test to see if that was the problem. And after bypassed, if it will start, what is an affective way to shut off the tractor? Will pulling battery cable do it?

I almost pulled it off but we have rain moving in and I don't want to expose it to the weather. It is currently outside since I can't get it started. I am covering it with a tarp trying to keep it as dry as possible. lol

Again, you guys rock!! Thanks for the help!

Jaymee

 

[North Idaho Wolfman]

Good morning. After lots of life getting in the way, I was able to go out and crack open the fuel lines at the injectors, and cranked it over, let it cool down, and do it again. I did this for about 30 minutes. Then waited another 30 minutes to let the starter completely cool down, and then do it all again for another 30 minutes. I am currently charging the battery again, since I ran it down some. The fuel coming out of the ends of the fuel lines, at the injectors, isn't much. Or at least, not what I expected it to be.

The engine started to sound as though it was trying to "hit" and maybe close to starting. Then it dawned on me. When I first bought this thing 7 years ago, I forgot to push in the stop lever and it seemed to have the same sound coming from the engine when cranking it. How does the stop lever function? I know it connects to some sort of valve right before the fuel pump and I presume it cuts the flow off to the pump when the lever is pulled out? How would I go about bypassing it? It would be a good test to see if that was the problem. And after bypassed, if it will start, what is an affective way to shut off the tractor? Will pulling battery cable do it?

I almost pulled it off but we have rain moving in and I don't want to expose it to the weather. It is currently outside since I can't get it started. I am covering it with a tarp trying to keep it as dry as possible. lol

Again, you guys rock!! Thanks for the help!

Jaymee

The stop lever controls the rack or governor on the injection pump, just make sure the lever is in the run state.
Removing the battery cable will NOT stop this running diesel, you must use the stop lever or cut off fuel externally.

Check that this lever moves when you pull the stop rod.
You could pull the rod off the lever just to make sure is going into run.

 

[jaymee01]

The stop lever controls the rack or governor on the injection pump, just make sure the lever is in the run state.
Removing the battery cable will NOT stop this running diesel, you must use the stop lever or cut off fuel externally.

Check that this lever moves when you pull the stop rod.
You could pull the rod off the lever just to make sure is going into run.

View attachment 154086

Thanks for the reply. Yes, the lever moves when it is in the run state. Lever is still connected. I figured if I could bypass it somehow, I would have to cut off the fuel, if the battery being disconnected didn't work. I just didn't know, even if it was moving to the stop position, could it be defective (Maybe part 120?) and it was "stuck" in stop mode, no matter where part 090 was positioned. Hmm. I will bleed the lines some more since I have a fresh charge. Unless anyone has an other ideas.

Thanks for all your help!

 

[North Idaho Wolfman]

If you really know if your getting fuel out of the Injection pump.
Remove the lines off the top of the pump, then set the throttle to high, crank the engine and fuel should fountain out of the pump outputs about 2 to 3 inches.
Now pull the stop lever and you should not get any fountains.
It should only take a about 15 min total to bleed the air out of the lines to the injectors.
If you are getting fuel to the injectors and it will not fire, you have one of several issues.
NO glow plug heating, no compression, or injectors that are simply not popping and injecting fuel.

 

[jaymee01]

If you really know if your getting fuel out of the Injection pump.
Remove the lines off the top of the pump, then set the throttle to high, crank the engine and fuel should fountain out of the pump outputs about 2 to 3 inches.
Now pull the stop lever and you should not get any fountains.
It should only take a about 15 min total to bleed the air out of the lines to the injectors.
If you are getting fuel to the injectors and it will not fire, you have one of several issues.
NO glow plug heating, no compression, or injectors that are simply not popping and injecting fuel.

I will check at the pump for fuel. I don't have that much out of the lines going into the injectors, and that is a short line so... I will see if pulling the stop lever changes any of that.

I changed the glow plugs first. Factory new. I have 12 volts at the rail connecting to the glow plugs when trying to start the tractor. I bled it for way longer than 15 minutes. No go.

It seems to have compression. I put my hand over the intake hose (filter and housing is removed currently, to give better access to everything else), and I had lots of intake suction, so I presume the compression is good. I didn't check at the cylinders, but wish I had while the glow plugs were out.

Plus, it would be odd that it ran fine and then it didn't The last time it ran, it started, ran for several seconds, and died.

I know I will get it and I appreciate all the help you guys have given!

Jaymee