7520 not running right, poor power, white smoke

   / 7520 not running right, poor power, white smoke #11  
Am I correct that the hand pump for bleeding the fuel lines should push the fuel through the injector pump on all 4 ports?
No, hand pump will only get you TO the injector pump.

Crank engine to bleed high pressure side.
 
   / 7520 not running right, poor power, white smoke #12  
I think I may have found the problem, and it ain't good. I discussed this with a tech at the dealer, and he told me that they have problems with the injector pump on this model (7520). Well, like I said earlier, I drained the fuel tank, checked the filters, and put fresh fuel in the tank. I bled to the banjo bolt (just after the secondary filter) with no problems. I then bled to the bolt where it enter the injector pump, no problem. I think cracked the high pressure lines on the other side of the pump loose, and I am unable to pump anything through. I pump and pump, no fuel. I bumped the engine to change it's position which didn't help.

End conclusion: I think I have a bad injector pump. Good news is I'm under warranty. Bad news is the guy I bought the tractor from says he doesn't do warranty work anymore for Mahindra. More bad news is wherever I go, I'm going to have to haul it.

:mad::mad::mad:

That good news may turn into BAD news real quick. Read your warranty. Tires, battery, and INJECTOR pump are by the manufacturer's warranty. In other words NOT BY MAHINDRA!!!!!!!
 
   / 7520 not running right, poor power, white smoke
  • Thread Starter
#13  
Ok guys, I fixed my problem. I think I've learned some interesting stuff about troubleshooting your fuel system.

I spoke with a Mahindra mechanic who really knew his stuff, and he felt that I had an air leak between the injection pump and the fuel tank. His suggestion was to stuff a rag in the gas tank opening and shoot compressed air into the tank, just a little, to find the leak. I did this an quickly found that the banjo bolt on the fuel line from the gas tank to the primary filter was loose. I hadn't messed with this one yet, so it must have worked itself loose. He also told me that sometimes you can't find the leak, but a surefire way to tell is to get an extra fuel line between the secondary filter and the injector pump to use for troubleshooting. Hook it to the injector pump and put the other end in a CLEAN bucket of fuel and see if that fixes the problem. Good idea, but I didn't need it thankfully, because I would have had to order a fuel line in order to try it. I wouldn't use the existing line because I think you'd have to cut it to put an extension on it to reach the bucket, and also it could be the one leaking.

Anyway, after locating my leak it ran great...for about 5 minutes, then it started choking again and stalled. I shut it down and tried it 15 minutes later and it ran great...for 5 minutes. That sounds like a clogged fuel filter, so I replaced both filters (aftermarket I picked up from Napa; I had put one in the primary filter bowl earlier, but when it didn't fix the problem I put the original back in since it looked fine). It ran great!...for five minutes. When it stalled it occurred to me to try and use the hand pump to see if that would get it going again. When I went to pull the plunger up, it was sucked back down, and wouldn't pump at all. Bingo! Obviously there was a vacuum in the line! I took the fuel tank cap off (which I had already tried before), and it didn't help. Still negative pressure at the pump. I traced the line back to where it enters the fuel tank, and there is a 4 inch piece of flex hose that had a slight curve but didn't look kinked to me. When I pulled the line to straighten it out, I heard fuel rush into the line and filter housing. I bent the line slightly to keep the flex hose straight, and voila! My problems are solved. It runs great now, and keeps on running!

I just wanted to share some troubleshooting techniques with you guys. Especially trying the hand pump when the engine stalls or is choking. That'll let you know if you have excessive negative pressure in the line. And the mechanics techniques for locating/diagnosing leaks.

End result. It's fixed! No hauling! No bills! No warranty BS! No kidding! :D
 
   / 7520 not running right, poor power, white smoke #14  
Yahoo, jrlogan. Good job. What a satisfying experience.
 

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