Fuel System Help

So I have been working on restoring my 72 4000D the past few months. Got it all painted and put back together enough to start it. First start, it started well. Ran a bit and fluttered some. I didn't give it much thought because I figured it may have some air in the line from being off, new filter etc. On the next start it flutters bad, changes rpm a bunch and dies and will not re-start. I start checking for the click in the fuel pump and don't hear much going on. So I took the cover off the pump and took the solenoid out. Hooked it to hot and ground and sure enough, it doesn't have the strength to pull the flapper closed. So I order a new solenoid, thinking that would be the end all cure (btw the new solenoid design is way better than the original). Anyhow, so I put the new solenoid on and the tractor fired right up. Then it proceded to flutter a bit like before. Again I didn't think much of it because of having the pump cover off, etc. I pull the tractor outside and it died again. Before it died, I noticed it didn't seem to have much power or pep. The engine sped up very slowly. This time, I could not get it re-started for nothing. I cracked injector lines, I opened fuel lines, I tried priming, nothing helped. I took the cover back off the pump to see if I maybe got the flapper in the wrong spot, but I couldn't really tell anything. As soon as I put the cover back on the pump and hit the key, it started like nobodys business. It ran a few min pretty nice and died again. Every time it dies, it's incredibly hard to get started. Each time I crack the pump cover, fuel runs out, but nothing ever coming out the top elbo (overflow?). I blew air thru the orfice and it's not obstructed. Have never had this kind of trouble before. I'm at a loss and wondering what to look for.

Typical symptoms of a plugged fuel return line fitting or plugged return line. Loosen IP timing widow screws and with gasket loose see if it will run. If so governor drive ring has deteriorated.

Remove the timing window cover and see if it will run...

(quoted from post at 14:03:11 07/22/15) Remove the timing window cover and see if it will run...

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When I was trying to get it started, I did open the window. During cranking, fuel would spurt out as it turned. I've noticed that whenever I can get it running, if I don't touch the throttle (or increase throttle), it will run a bit. But as soon as back off the throttle, it flutters and dies.

Take the timing door clear off and try it,, it will leak a bit but not bad,,if it will run that way the return is clogged..

Tim S and Texas Jim are spot on, the pump needs serviced soon before more damage is done. As far as the solenoids go, if the original is the flapper style they will not pull in on their own, the small linkage spring has to help on the linkage inside when the cover is on. Some will not even pull in until the throttle is opened too. The new style plunger solenoids work without relying on help from the internal linkage. Best get the pump repaired soon before the retainer pins shear off, wrecking the pump. Had a neighbor ruin his pump on his IH 806, he knocked the return fitting ball out and kept on running it. Was not happy when the pins sheared, locked the hydraulic head and broke the drive shaft..

I'm wondering if the rack could be sticking shut somehow. Last time I had the cover off, I tried moving the spring-loaded part up and down and it did seem to hang up a bit in one spot as I recall. This tractor ran quite well up until I started painting on it. So it's not like it slowly degraded. It just acts like it's off. I'll fiddle with it some more tomorrow. Maybe it does need serviced. I hate that becuase I just got it all painted and it looks so nice.

Also, when I took the old solenoid out, the casing had some cracks in it. I reasoned that this may have shorted it out or at least weakened it a bit. Because when I energize it and tap the flapper, it sucks in but not very stong and will intermittantly let go.

I did manage to get it running. I took the top cover off so I could see what was happening and the rack is sticking sometimes in the up (off) position. I can reset it manually and the tractor starts right up. I removed the timing cover and the tractor runs the same with it off. But it still doesn't run quite right. If you put the throttle to it, it just fine. But if you back the throttle off, it starts to cut out and run rough. But a little throttle and it will recover. It seems like it could be in the governor system.