My experiences with Mahindra tractors has shown that this particular symptom can be caused by at least two separate problems. One is fuel blockage/starvation due to restriction somewhere. Another is the pump timing issue. My observations of each show the smoke puffs with timing problems will be more blue/gray in color while fuel supply problems cause the color to be closer to white. Timing issues usually occur within the first 150 hrs of operation, you must be well beyond that. With the timing problem, the condition most often comes on after the cold start timer goes off(about twenty minutes), and can continue until the engine is switched off and restarted. It will often return after another twenty minutes or so. The blockage problem can occur at any time, so stopping and restarting the engine will have little or no effect. I suspect your problem is supply related, and would suggest you place a pan below the fuel filter assembly and remove the banjo bolt from the outlet fitting( the line leading up to the injection pump) and observe the flow for a minute or so. Since the filter base is mounted low, the fuel will gravity feed at a good rate. It should continue at this rate until the tank empties, and not quickly reduce to a trickle. This may give an indication of where to go next.
:thumbsup:
First, Harry how do I mark your post as 'sticky' or very useful. Your reminder to approach this problem with logic is refreshing.
Outcome - fuel flows freely up to the hand pump
Details follow
I chose "fuel blockage/starvation due to restriction somewhere" because
1. I remembered the smoke being closer to white than blue/gray
2. My 6500 has about 225 hours
3. stopping and restarting had no effect
So , I did as you suggested
1. "remove the banjo bolt from the outlet fitting( the line leading up to the injection pump) and observe the flow for a minute or so."
Result is a bunch of diesel on my hands making wy wife say 'ooooo yuk' when I come back in to type this. But, then the leaking diesel stopped. After checking that the petcock is open I realized that I still have a fuel blockage problem.
2. Next, I removed the banjo bolt from the inlet fitting. The steady stream of diesel did not stop. OK, got diesel to this point.
So, then I planned to open each bolt between here and the outlet fitting to isolate the blockage.
3. The primaty filter(closest to tank) drain flowed freely
4. The secondary filter(closest to pump) drain flowed freely.
HUH? The blockage is between the secondary filter and the outlet? There isn't any other opening to check between these two points. The only thing between them(sort of) is the hand pump. Asked myself, how can the pump be restrictive?
I opened the pump handle and got a little faster stream from the secondary filter drain.
I operated pump 1 stroke and got a face of diesel. Oh yeah. The outlet banjo bolt is still removed.
So, fuel flows freely up to the hand pump. What is blocking it between beyond here?
Remember earlier I had operated the hand pump when tractor was running but sputtering. The hand pump had a vacuum on it. The upstroke was resistant. The downstroke was not restrictive.
Does the entire filter base have to be removed next? Any precautions to doing this?
