Intermittent rough running, coughs when starting

[BeezFun]

My first thought was moisture, or just a little bit of water, in the fuel tank.

Fuel filter was packed with crap when I bought this thing, so I emptied the tank and refilled with fresh fuel using a Mr Funnel which separates the water. Also purged the fuel lines to make sure they flowed freely.

 

[BeezFun]

My friend made a useful observation, if the tank is full there's no need for the fuel pump because the height of fuel is well above the injection pump. I filled tank and still have the same issues, so I think that rules out the fuel pump as a problem. The fuel pump is only needed when the fuel tank is below about 1/3, that's when the fuel drops below the injection pump.

 

[BeezFun]

I took the injectors over for testing, one didn't work at all, it was returning fuel through the return line. One was leaking and the other had some problem I can't remember. Anyway, he said he's surprised it ran at all. He didn't charge me to test them, will call tomorrow once he gets them apart to let me know how much for rebuild or if they need to be replaced. I got the guys name from local dealer, dealer sends all their injector work out to this place.