simms making foam

karl f

Well-known Member
My brother changed the injectors on our 5000. He says it started right up and ran fine, but he saw leaks on the injector bodies. He took the lines off and tightened the injector bodies. (aftermarket parts) Then it was only running on a few cylinders. Then he asked for my help. I determined which cylinder wasn't firing--nothing but foam at the injector and then it started running on 2 cylinders, the adjacent injector was foaming too. There's no air in the filter or pump when you open the bleeder screws. A few days later, I try again--this time I use the crank at full throttle with stop pulled and lines cracked bleeding method (forgot about that before). I got back the first cylinder but the second is still foaming even after lots of cranking and running open time.
I think it's the injector pump at this point. There's still no air at the bleeders so there has to be a check valve or plunger problem.

am I on the right track?
thanks
karl f
 
Have seen the trouble you have if injector tips are stuck open, compression pressure will blow through injector if needle is stuck off the seat. Check with injector line completely off at injector inlet on suspect injector and run engine. Should be no air coming out injector inlet if working correctly. Also if hold down hardware not evenly torqued needles can stick if injector is in a bind causing the same problem. When stuck open will look like foam when pump delivers fuel to injector. Make sure no air at pump block front bleeder, if OK I doubt you have any pump trouble.
 
Had a customer,just last week on a TW-5,chopping alfafa,. Tractor quit dead in field, fuel system was full of air. Changed filters,bled, bypassed the filters,lift pump etc. No Luck. Then it hit me maybe a stuck open injector.Turned out to be #3. With the line loose on #3 the tractor would run perfect on 5 cylinders, As soon as you tightened the nut it would die dead.Changed the injector,problem solved.
 
Well, the injectors were stuck--another one started acting up too!
Nothing related to uneven bolt tightening, it was more complex than that. After no positive results, I took the offending injectors apart and there were iron shavings inside. Apparently a cost-saving measure in production eliminates the step where the castings are cleaned out after machining.

runs on all 4 now but still has the wide open miss it did with the old injectors. They did need attention though, but they should have been serviced instead of replaced.

sometimes new isn't better

karl f
 
karl
Regarding the high RPM miss
When was the last time the valves were properly adjusted?
Try re-setting them to spec and see what you have.
Brian
 

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