Gday all, my Bobcat 331 reciently was loosing power under load. I soon discovered that there was a lot of algie in the fuel tank. I removed the tank to also find that the fuel pick up hose was perished. I hot washed the tank and replace the pick up hose. I also got the injectors freshened up while it was out of action. I have got it all back together but it is still fluttering. Almost like a petrol car running on 1 less cylinder then it should?? Although it's going better it's still not rite. It's like I'm missing a bleed screw somewhere and it has a tiny bit of air?? Pls help!! I'm out of ideas!!
You probably still have crud in the fuel supply lines. Replace the filter and remove every fitting between the filter and the tank, blow out the lines and inspect the fittings. Check for cracked or soft spots in any flexible lines.
I would think with all the crud in the system, perhaps a new injector is clogged. get it started, then crack each injector, in turn, to see if one has less effect, than others. If you do find a cyl that doesn't appear to affect how the motor runs, pull that injector, and switch it out with one of the others. Then repeat the first test. This will tell you if the problem moves, with the injector. Also, if it has a return line, to the tank, check to see if it is kinked, or plugged...:idea