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KevinB, Technician
Category: Heavy Equipment
Satisfied Customers: 228
Experience:  Cat Field Tech for 6 years, John Deere Field Tech For 5 years
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The injection pump, I need exact timing specs on a 4BT diesel cummins

Resolved Question:

I have problems setting time on the injection pump, I need exact timing specs on a 4BT diesel cummins.
Submitted: 7 years ago.
Category: Heavy Equipment
Expert:  KevinB replied 7 years ago.
Does this engine have a inline or rotary pump?
Customer: replied 7 years ago.
It has an inline.
Expert:  KevinB replied 7 years ago.
OK behind the pump there is a plunger that when you push on it and rotate the engine it will engage in a timing hole. Next there is a rectangular cover on the side of the pump with two bolts holding it on remove these bolts and the cover inside will be a plastic piece with a forked end on one end. This will be facing out toward you when you remove the cover. With the plastic piece out spin the pump cam and you will see a tang in the hole insert the plastic piece so the forked end engages the tang. Now the pump and the engine are timed install the pump. Kevin
Customer: replied 7 years ago.
I already set it as you say to, and it doesn't fire. So i tried a 180 degree turn on the timing marks & it will fire but piston #1 will not fire ,it misses. And all settings on overhead are to specs & motor is brand new as well as injectors & the injection pump is a re-man.
Expert:  KevinB replied 7 years ago.

Pull your valve cover off and check when the pin engages the timing hole if your intake and exhaust valve are loose on #1.

Edited by KevinB on 12/16/2009 at 3:57 AM EST
Customer: replied 7 years ago.
I already pulled the valve cover & checked the valve latches. The intake is at 10 & the exhaust is at 20. I also already switched the injector to a different hole & it still does the same.
Expert:  KevinB replied 7 years ago.

I'm not talking about your valve clearances, what I am saying is with the engine pined with the timing pin the valves should be loose on #1 cylinder. This will prove that you are infact on TDC #1 which is where the engine needs to be to time the pump correctly. If these valves are not loose and your valve lash is correct then you have a gear timing issue. Kevin

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Customer: replied 7 years ago.
They are loose when the timing plunger is on the gear. What kind of gear issues could i have?
Expert:  KevinB replied 7 years ago.
If the valves are loose with the engine timing pin in the timing should be on. The engine should be on #1. Was the front cover off the engine are you confident that the gear timing is correct?
Customer: replied 7 years ago.
yes sr
Expert:  KevinB replied 7 years ago.
Well if your sure your gear timing is correct and you have the pump timed with the timing tool I don't see any reason why the engine will not run correctly. Are you getting plenty of fuel out when you bleed the nozzle lines?