Question for injection pump experts

Papaw8 · Dec 24, 2018

Worked on a 4030 jd with jdb pump.elastomer ring disentigrated installed seal kit no glass ball in return.tractor now runs fine for a minute or so then sluggish above 1500 rpm. Put clear hose in return see about 4 bubbles every 15 seconds.replaced lift pump no help.transfer pump pressure about 30 psi but guage needle has rapid fluctuation. No suction at transfer pump.pulled pump back off going to tear down again.plenty of fuel delivered to injector pump.going to look for vent wire.any ideas appreciated.thanks.oh yes set 5 gallon can on floor with electric pump from an old gm Tbi car run through inline filter to injector pump runs fine at all speeds all the time.thanks

Dieseltech · Dec 24, 2018

The injection pump is either STARVING for fuel, or the RETURN line side is still blocked partially or completely causing the shutdown. That's why I test the return side by taking loose the two screw timing cover. If engine runs fine with the fuel leak the return side has problems. What you say is it runs fine with a bucket fuel source makes me think you have a supply side problem. Place a Tee at the supply pump inlet and put a vacuum gauge on it. A system that's OK will have no more than three inches vacuum while running, any more means a supply side restriction. Your pressure gauge fluctuations means fuel starving too.

onefarmer · Dec 24, 2018

I'm thinking the shutoff in the bottom of the tank is mostly plugged. I had a similar problem with my 4430. Mine has diesel algae in it. For a temp fix remove the fuel cap and using your air hose blow back up the fuel line.

I eventually had to remove the shutoff, flush the tank, and add some algaecide with the fresh fuel.

Papaw8 · Dec 24, 2018

Thanks will do. I pulled a vent wire out of something one time and left it out.ignorance on my part.dont remember if it was this or something else.this has a vent beside of metering valve but not the screw in type. Looks like a pin sliding back and forth.this transfer pump will not pull fuel out of jug setting on floorboard.thanks

Papaw8 · Dec 24, 2018

Will check fuel shutoff also,however while running on a jug had factory fuel supply line pointed in another jug.pumped a good steady stream continuously. This transfer pump will not pull fuel out of a jug setting on floorboard of tractor.thanks

onefarmer · Dec 24, 2018

Well if the fuel pump won't even pull and pump out of a jug then it must be bad.

PS!! When you figure it out come back and let us know.

Papaw8 · Dec 24, 2018

Will let you know if I get it going right. I was referring to the transfer pump in the end of the injector pump will not pull from a jug. Already replaced the lift pump on side of engine block,thought it was getting air through diaphragm but no help.lift pump supplying good steady stream to injector pump.did not replace blades or liner in transfer pump.i will get back to it in a few days will also check with timing cover loose.return line not completely blocked could blow through it by mouth.thanks for all suggestions

Papaw8 · Dec 24, 2018

Also while running on a jug had a in tank type of fuel pump dropped down in jug(from gm car) through a clear inline filter to injector pump.tractor would not run without electric pump running.

Question for injection pump experts

Papaw8

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Dieseltech

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onefarmer

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Papaw8

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Papaw8

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onefarmer

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Papaw8

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Papaw8

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