1979 Ford 2600 Diesel very hard start and won't rev up (

[cdlane]

Hello, I picked up a 1979 Ford 2600 Diesel. Tractor will not start without starting fluid, once started it idles at a elevated idle (probably around 1100-1200 rpms.) Tractor runs ok, and has very strong hydraulics and will idle around with a good amount of power. However, if you try to give it any throttle it immediately dies. In low it'll run around fine but it dies in higher gears. The person I bought if from had this issue and replaced the pump and injectors and then sold it when it didn't make any difference. The pump is clocked at 0 degrees, which is where they said the last one was at. Checked all lines, pressurized the tank, changed filter and and o-rings, checked routing of fuel lines. Return to fuel tank seems to be flowing well. Not sure how to proceed, but has anyone seen anything like this? Wondering if maybe a crack in the filter housing or ? Searching online the biggest cause seems to be air ingress, but all my lines seem good. Pulled the shutoff out of the tank and it's nice and clean and flows well, pull the bleeder on the filter housing and freely flows there as well. Any suggestions or feedback would be appreciated.

 

[Sean in PA]

Have you checked the compression?

 

[cdlane]

I have not, as well as it runs at the idle, I hadn't thought to. I'll see about getting a fitting to work on the Ford diesel. Thanks!

 

[Sean in PA]

The first symptom of low compression in a diesel is hard starting. If it's been taking ether to start it for very long then that has probably made things worse.

 

[used red MN]

Hello cdlane welcome to YT! Fairly sure Seans suggestion has more to do with the symptom of hard starting than anything else. Hopefully you know low compression makes diesels start hard. Is anything holding the fuel lever from returning to the stop? Or have you tried adjusting the stop screw on the pump lever to see if it slows down? Is this a symptom that it had previous to the pump change or only the lack of power? If you crack the lines at the injectors while it is running do they all seem to affect the idle, as in you can tell it causes each to misfire? If not all the cylinders are firing then this could be part of the explanation of low power. There is a poster on these forums who posts as Dieseltech he runs an injection pump repair shop. Hopefully, he will see this and give you some other info. If he does not I will come back and direct you how to contact him.

 

[cdlane]

Yes, I understand the possibility of compression affecting starting. The lever is returning to the stop and when I back the screw to lower the idle it just dies. From what I understand the previous owner replaced the pump and injectors with new and it made no difference other than reducing some slight smoking from the injectors. All cylinders do drop when loosening the lines to each injector. Thanks for your reply. I've ordered an adaptor to test compression so should be able to test later this week.

 

[Tom in Mo.]

Start looking at the fuel supply from the tank. You should have solid flow to the pump from the tank. It won't start or run if the fuel is choked off from the pump.
Don't ask me how I know

 

[Bern]

While low compression could very well cause hard starting, it has absolutely nothing to do with the engine dying once it's running and you try to rev it up. Sounds more like a pump governor problem to me. The only problem with that theory is that you say the pump was replaced and it does the exact same thing. Hmmm...

As others have said, make sure you have good flow to the back of the injection pump. If that checks out, try disconnecting the air cleaner pipe where it connects to the intake manifold. Maybe the air cleaner is plugged and it's starving for air. A long shot would be a plugged muffler - see if it runs any differently with the muffler removed.

 

[cdlane]

Fuel supply seems great, no obstruction at the tank, runs through the filter and to the pump great. Also, return to tank running well.

 

[cdlane]

Checked the air filter/intake but didn't think to check the exhaust. They ran a pretty extensive exhaust that runs down, beneath the tractor and runs to the rear of the tractor, elbow up to exit along side the ROPS and has a flapper at the top behind the area where you sit. I'll look at that after work today. Thanks!

 

[Bern]

Don't just check the air filter, completely disconnect the air inlet pipe at the intake manifold and then run it, in case
something got shoved deep into the pipe. Stranger things have happened.

If the fuel supply is good, and the intake and exhaust systems are unobstructed, then I'm going to submit that you have an
injection pump with a problem identical to the first one. As I said earlier, low compression could indeed cause hard starting,
but it will NOT cause the engine to die when you try to rev it up off idle.

 

[cdlane]

Ok, pulled exhaust because it was quite pinched. No difference. Unhooked intake hose to intake manifold to check for obstructions and nothing. Still waiting on the adapter to check the compression but there is 0 blow by. Will confirm when the adapter arrives. Checked and what I thought was good return from the injectors was actually just a bubble of fuel pulsing. It is not returning to the tank. How much should there be? The return line goes from the pump, through the tops of the injectors into a T fitting from the intake manifold and then to the tank... could there be an issue here? All three injectors are contributing and it dies off some when I loosen each line... Thanks