Forum › Forums › Tractor Troubleshooting › Fuel injection pump on 354 with 395 non epa engine
- This topic has 19 replies, 6 voices, and was last updated 12 years, 3 months ago by Bob Rooks.
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August 19, 2012 at 11:17 am #30640
Hi evryone
I just replaced the engine on my 354 with a short block and head. I replaced the fuel injection pump 2 years ago and used it to start the engine only to find out the engine needed more work. We replaced the block and head, then put erverthing else back to gether and tried to start the engine with no luck. When we tried to pump up the pump with the primer pump it wouldn't pump, it was like it was pumped up with fuel. I took off the 2 bango bolts on the top of the pump and switched them. The single bolt that was on the front was put on the back and the 2 part bolt (bolt within a bolt) that was on the back was put on the front. I could then pump the primer pump with no problems. The problem is now this. I can get fuel all the way to the top of the pump but nothing to the injectors. I can get it to go all the way thruoght the pump and out the other side but it will not come up into the injector lines on the top of the pump. There is fuel coming out the other side of the pump. This appears to be the return line tha goes to the tank. Looking for help again guys. Thanks
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August 19, 2012 at 4:00 pm #34995
If I correctly recall something I read on one of these forums, one of those banjo bolts incorporates a check valve in its construction/assembly. It is necessary that that particular bolt be in the correct location so it prevents backflow of fuel and loss of pressure in the lift pump. I *think* it was Bob Rooks who brought up this issue a couple years ago. Maybe he'll recall it and can give you more and better information.
You do have the pump timed correctly, right?
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August 19, 2012 at 5:07 pm #34996
Hi Rich
I switched the banjo bolts on each end to see what would happen. When I had the banjo bolt with what looked like the check valve in it on the back of the pump (connected to the line from the filter) I could not get the hand primer to work. It acted as though it had been pumped up and couldn't get any harder. When I switched the banjo bolt with the check valve in it to the front of the pump (connected to the return line to the tank) The hand primer pump could be continously pumped without getting any harder to pump. The pump has been timed. I used a small amount of starting fluid to dtermine if it was a fuel problem and it started right up. So I am assuming that it is a fuel problem since it started with the staring fluid and I can't get the fuel to pump up any further than the pump itself. With the banjo bolt with the check valve in it connected to the front of the pump I can get fuel to the pump and through the pump to the return line but not up into the injector lines leading up to the injectors.
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August 19, 2012 at 6:13 pm #34997
make sure the direction of flow on the check valve is correct and let the air out at each injector at the head while pumping the primer.if it is in time and compression and fuel and air is there it will run,I think there is someting there with air ,if not let out the manual pump I do not think can overcome the backpressure to push fuel into the injector.
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August 19, 2012 at 10:32 pm #34998
Why is there a check valve?
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August 19, 2012 at 10:51 pm #34999
I second the
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August 20, 2012 at 3:48 am #35000
Ok, then I will digress.
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August 20, 2012 at 2:21 pm #35001
I was told on one side there is a regular banjo bolt and on the other side there is a bolt with a check valve in it to keep the fuel from running back out of the pump or somthing to the nature. When I put the regular banjo bolt on the back side (tank side) and the other bolt with the check valve ( return side) I was told it was called that I can pump the hand primer but it doesn't get hard to pusheven after I've been at it awhile. If I put the check valve bolt on the back side (tank side) and the regular bolt on the front side (return side) I cant get the primer to pump at all because it is instantly hard when I try to prime it .
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August 20, 2012 at 7:03 pm #35002
Hi everyone
Can anybody give me some good advice with my problem? Thanks
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August 20, 2012 at 8:37 pm #35003
ok take out the check valve and try pumping up the system and see if you get fuel to the injectors.you might want to look at a filter screen .there might be one at the in part of the fuel line at the injector pump at the manual pump inlet.I do not have a jimma so I am guessing about one being there
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August 20, 2012 at 9:26 pm #35004
I'm not going to go into detail here but the so-called “check valve” must be installed on the outlet side of the injection pump fuel cavity (doesn't matter what end of the pump it's on, it's just one big cavity), and connected to the return line to the tank. Every diesel engine in the world has some such device and their purpose is not that of a check valve.
The resistance you should feel by using the lift pump to prime the primary side of the fuel system is governed by the strength of the spring in that “check valve”. If you feel little or no resistance then the spring is weak and the “valve” should be replaced, however, this would not necessarily keep the engine from starting. Some “check valves” are adjustable. There is also a chance that corrosion has destroyed the ball and seat contact point, rendering the valve useless. Ya gotta keep the fuel clean, dry (no water), and free of bugs.
You cannot prime the secondary (high pressure) side of the fuel system with the lift pump, this can only be accomplished by turning the engine over.
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August 21, 2012 at 10:21 am #35006
Thanks for that, Bob. Now, can you tell us what that ching is properly called? I used the term “check valve” since it works somewhat like one, but I know that isn't correct – I just couldn't remember the correct term from the last time this came up. Thanks.
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August 21, 2012 at 1:33 pm #35007
Hi Bob
If I understand you correctly the hand pump should get fuel up to the top of the pump only. Then by turning over the engine you get the fuel up to and including into the injectors to start the motor. If I can get fuel up to the top of the pump where the injector lines connect but no further the what could the problem be? I have what we will call the check valve connect to the return line that goes up to the injectors and on to the tank. With this connected this way I can pump forever and not get hard prime. If I understand you correcetly this means that that valve is weak and is allowing fuel to up through the return line instead of stopping the fuel in the top of the pump and letting it go up to the injectors through the top of the pump. Please be paitient with me as I am not even a good backyard mechanic but slowly learning from experience. Thank You!!!!!
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August 21, 2012 at 3:56 pm #35008
Stupid question: the fuel shutoff cable isn't stuck open on anything is it?
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August 21, 2012 at 6:43 pm #35009
Rich wrote:
Now, can you tell us what that ching is properly called? I used the term “check valve” since it works somewhat like one, but I know that isn’t correct – I just couldn’t remember the correct term from the last time this came up.
It seems like every engine manufacturer has their own name for it, but generically speaking it is a pressure regulating valve. The fuel pressure is regulated by the spring tension against the ball and is usually preset to between 20 and 35 psig. This pressure helps keep the fuel from aerating, and keeps a positive head on the plungers (like keeping them primed).
There are lots of different types of check valves, and this particular valve could be used for a spring loaded model, however, that is not it's purpose here. A “check valve” in the return line isn't really necessary but a “pressure regulating valve” is. It probably seems like a battle of symantics to the lay person, sorry.
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August 21, 2012 at 6:49 pm #35010
zRoger,
Nope, you misunderstood Bob, I think. You will *never* get fuel to the injectors using the primer pump. The primer pump only gets fuel from the tank to the injector pump, no further. From the injector pump to the injectors is solely done by turning the engine over to activate the injection pump circuits. The hand pump might never get to hard pump like a boat primer does, even with the pressure compensating valve (or whatever its called) working properly. That valve is only intended to provide sufficient back pressure for the hand pump to function, as I understand it from what Bob posted.
Once you have fuel in the injector body with the hand pump, you'll need to pull the injectors loose and turn the engine over to pump fuel up to them. I'd suggest pulling the compression release and locking it open while you do this to save wear and tear on the battery and starter, but lots of guys do it without doing that and ju st let the thing start when it gets sufficient fuel up to one of the injectors. When you get a decent bit of fuel coming out around the injector, screw it back down. Once all the injectors have fuel to them, then undo the compression release and fire it up.
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August 21, 2012 at 6:51 pm #35011
Thanks Bob, I was apparently busy writing while you were posting that, so I called it the wrong thing again. At least I called it a *different* wrong thing, right?
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August 21, 2012 at 7:04 pm #35012
No problem, and I apologize for my goof.
The lift pump and primer pump are two separate pumps, incorporated into one body, but use the same check valves. WOW!
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August 21, 2012 at 7:27 pm #35013
Roger wrote:
If I understand you correctly the hand pump should get fuel up to the top of the pump only.
Correct. Fuel flows freely from the priming pump, through the secondary fuel filter, and into the injection pump fuel cavity (chamber).
Then by turning over the engine you get the fuel up to and including into the injectors to start the motor.
Correct. The barrel and plunger assemblies (the individual pumps) are operated by a camshaft in the injection pump and fuel is metered to the injectors by rotating the helix on the plunger with the rack.
If I can get fuel up to the top of the pump where the injector lines connect but no further, what could the problem be?
No problem. That is as far as you can go with the priming pump. It doesn't have the capability of bypassing the lap fit of the plunger assemblies.
I have what we will call the check valve connect to the return line that goes up to the injectors and on to the tank. With this connected this way I can pump forever and not get hard prime. If I understand you correcetly this means that that valve is weak and is allowing fuel to up through the return line instead of stopping the fuel in the top of the pump and letting it go up to the injectors through the top of the pump.
The Pressure Regulating Valve (PRV) must ONLY be on the return line to the tank. As Rich stated, you won't necessarily get a “hard bulb” with the priming pump but you should feel some resistance, and maybe a squeaking noise, after several strokes.
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August 21, 2012 at 7:53 pm #35014
Tinbender also makes a very strong point.
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