1983 Ford 1700 ...just won't get rpms up

[jpilk99]

Seemingly overnight, my awesome 1700:

Had a harder time than normal starting
Actually seemed to 'catch' and run okay, but, just wouldn't get it's idle or rpms up
It surged for a minute or two and then ultimately ran ...okay. I've got the brush hog on but not slogging through anything crazy or wet.

Then, after sitting all night on a slight grade - so it was kinda tipping to the left a bit - same thing in terms of a little hard start, but, once it was running, just surging - slowly - and never evening out at the normal great idel/rpm (once throttle arm opened up).
I thought I might be low on fuel, and especially tipping to the side, so I dumped in what diesel I had (barely a half a gallon), and no difference. Went and got a 5 gal tank filled, came and dumped it in and almost the same thing.
I put it in gear and drove to level ground and the idle came up a bit ...but it just seems to be running at 1/2 to 2/3 power. I thought of my other lawn tractors when only running on one cylinder - but that was always because of spark missing (either bad plug or ignition coil). Obviously not the case on diesel.
I took a pass in the field with brush hog going and it did okay, but, just no rpms/no power. And it was running strong AF 2 or 3 days ago.

Did I somehow get air in the fuel lines, once fuel level was low and machine tipped to one side?
I wondered if I put bad/old fuel in it, but, after dumping in the better part of 5 gallons of fresh diesel, I can't believe that would be the issue.

Any ideas?

Thank you,

Jay

 

[JC-jetro]

Jay,

1. Make sure fuel cap is venting. it does have a hole on the bottom of the cap that let the tank breath.
2. You can remove the hose from tank in to your filter assembly with the valve closed. Get a cup under the fuel line and open the valve. You should have a steady flow. if you don't then you might have some sludge build up on the bottom of than tank. I had the problem once. I welded a long thin all thread to a wire brush, put it on the drill and cleaned up the bottom of the tank. I vacuumed the bottom clean and then I had nice steady flow.
3. If yiu had a lot f air in the injector line then you would not be able to start. Once engine is hot you should be able to entirely bleed the air without issue.

I think your issue is fuel delivery.

 

[jpilk99]

Thanks JC (as always). I bled the fuel lines and it seems to be running ...well(?). Still feels like the rpms aren't audibly as high as I recall, but, the tachometer
says I'm running at the proper rate. I'll keep an eye on things, but, thanks again.

 

[JC-jetro]

Thanks JC (as always). I bled the fuel lines and it seems to be running ...well(?). Still feels like the rpms aren't audibly as high as I recall, but, the odometer says I'm running at the proper rate. I'll keep an eye on things, but, thanks again.

Jay,

Does your tach work? How high can you raise your rpm if it works. I hardly ever need to go over 2100 rpm for all my brush hogging even tilling. At 2450 engine RPm you are getting 540 pto rpm.

 

[jpilk99]

I usually bring it up just under the "PTO" icon around the 2500 rpm range.

 

[Btown]

I would check fuel filter and air filter.