Lift pump question.

[Kevin Foust]

I've got a 1998 JCB 214S backhoe with a turbocharged Perkins Diesel. Owned it for 3 years and want to get this issue solved. Preevious owner had the same issue so I bought it with it. Engine will fire right up then die after 2 -3 seconds. then you have to crank for quite a while before it with hit and start. Then it runs fine. If you stop and restart it would nornally take 24 hours till it would do the quick kill. I have replaced the fuel filters, cleaned the sediment bowl which is transparent. Fuel looks fine with no signs of algea. Previous owner had bypassed the factory lift pump and put a tiny electric one on it. I am no expert so any advice would be appreciated. Is there a spec on how many GPM an electric should pump? Is the aftermatket electric better or should I go back to the factory one? Today it needed cranking after about 2 hrs so it seems to be getting worse. I'm wondering if the lift pump that is on it now is dying. Am I on the right track?

 

[Eric Forstrom]

Kevin, Sounds like you have air getting into the system and you are losing prime to the HP pump. The reason it starts right up and then dies is because the HP pump to the injectors still has fuel, there isn't any fuel from the lift pump to the HP pump. I had this exact same problem on my John Deere backhoe. At first I suspected my lift pump, so I put a new one on and it still didn't start. I ended up putting the old pump back on the engine because it was a better pump. Then someone on the forum suggested that I check the supply line from the tank, because the o-ring seal often fails (which would cause an air leak). I did this, and it still didn't want to start. Then I thought that maybe the pump was loosing its prime, so I put a small check valve off the tank outlet. At the same time, I changed out the old fuel hoses and tightened some fittings on the fuel filter. I found one of the fittings on the fuel filter was quite loose. Anyway, somewhere in all that I fixed the problem and now it starts right up every time. Hope this helps.

 

[franklin2]

Yes, these systems are like the fuel system on my old diesel pickup. Ever take a straw in a drink, put your thumb over the straw, and pull the straw out of the drink and the drink stays in the straw as long as you keep your thumb sealed over the end of the straw?

That's how these fuel systems work. The fuel is supposed to "hang" in the system till the next time you go to start it. A very minor leak is all it takes for the fuel to run back to the tank. A clue as to where the leak may be is dampness at a connection or hose. A very small hole will not leak much fuel, but can let a lot of air in.

 

[thepumpguysc]

That inj pump requires 5 psi at the pump inlet..
Hope that leads you in the right direction..

 

[Kevin Foust]

That inj pump requires 5 psi at the pump inlet..
Hope that leads you in the right direction..

Here is what I found. It looks like I do have a check valve before the tank.

Looked at the lift pump and both wires were off.

That explains why it was so hard to restart even though it was just minutes after shutting down last time. That had never happened before. They are push on connectors like a spark plug. Put the back on and it started like normal (hit/die/crank for a while then ran. Restarted fine. Used it a while in the cornfield and switched to another piece of equipment. When I went back to the hoe, turn the key and no pump noise. Looked again and wires were off.

They mounted the pump in a bad spot to me. In the rear wheel opening. Had a hunch and turned the steering wheel. (This has 4 wheel steering) The tires come right to the pump and any mud or cornstalk will hit/tweak the pump. I then noticed a drip coming from the end of the pump where the wires are. I'm guessing something has hit it and tweaked it.

I'm pretty sure this is the culprit. My plan is to get another pump and mount it out of harms way. The line to the Injector pump is dry when I followed it. Fine where it goes into the pump too.

What is the piece below the pump itself? Regulator? What pump would you recommend? I like the idea of an electric as it primes before cranking.

 

[franklin2]

I love these little pumps. Cheap and they work. I have one on my diesel pickup, one on my diesel lawnmower, and one on my gas Bronco II.

https://www.amazon.com/Electric-4-5-7psi-Universal-Standard-Installation/dp/B07W3DRZ41

 

[Diesel Dave]

That fuel check valve looks very similar to an old school Detroit Diesel piece.
When the DD fuel check valve was mounted horizontally the word “TOP“ or “UP” stamped in to the housing was to be oriented facing up.
Just something to verify.

 

[joe--h]

https://www.amazon.com/gp/product/B00L8IHM9K/ref=ox_sc_act_title_9?smid=A1M3N8TKC4WH0J&th=1

Half the price, same result.

Joe H

 

[Tinkerer]

Have you considered using the OEM lift pump that Perkins designed the engine to use ?
I cannot think of a reason to bypass it unless the camshaft lobe has tooo much wear on it to give the pump the full stroke it needs.
The OEM lift pump has a fuel strainer in it and may simply be plugged with crap.
If you choose to keep using an electric one ,the lowest psi it can pump should be at least 5 PSI.
It may run with less than that but thepumpguysc usually recommends 5.
Locate it as low as is practical to the fuel tank outlet. That will reduce suction it needs to pump the fuel and it may also result in a higher PSI at the injection pump. IMHO of course.

 

[joe--h]

It's a lot easier to bleed the system with an electric pump. My Perkins lift pump is on the right side of the engine, all the lines are on the left side. My arms aren't long enough to pump & bleed.

Joe H

 

[Tinkerer]

It's a lot easier to bleed the system with an electric pump. My Perkins lift pump is on the right side of the engine, all the lines are on the left side. My arms aren't long enough to pump & bleed.

Joe H

True, but even electric pumps sometimes need help with a difficult priming operation.
3 t0 7 PSI of air injected into the fuel tank will make the job very easy and simple.
If the tank has a breather it would need to be disabled.
I would conservatively say I have primed 300 hundred different kinds of machines using that method.
On one job I was on the contractor I was working for bought a load of "cheap" fuel.
It was contaminated with water.
14 Cat 631's all the push cats and dozers had to have the fuel drained and replaced.
I was running a service truck and had to do them all.
The air pressure in the tanks made it a fairly simple and fast operation.
I liked that Caterpillar had breather holes in the fuel caps and a blow gun with a rubber tip worked great.
Most other types of caps I wrapped a rag around my blow gun and applied the air that way.

 

[joe--h]

That's fine, but if I don't have an air supply I still have the electric pump. They don't all die in the driveway.

Joe H

 

[Delmer]

If the tank doesn't have a vented cap, then it usually has a vent hose, the vent hose is even easier to pressurize with an air blow gun. A vented cap you can remove and use a piece of inner tube with the valve with a hose clamp if the tank filler will hold it. Then add just enough pressure to lift the rubber but not pop it.

 

[Kevin Foust]

The new pump arrived and I hob cob installed it using the lines/routing they had so I could move it into the shop. Calling for rain soon and in the field. Hooked the feed line up along with the electrics and keyed the ignition to bleed the fluid out of the pump as it seemed like solvent. Then hooked the out going line up and bled it to get the air out. just a little cranking and it ran fine and drove it to the shop. I now want to hook this up correctly but the way it is doesn't seem right with me. Forgive me if this seems dumb but trying to learn here.

They have the feed to the pump coming from the TOP of the fuel tank as shown. Is this correct?

The outgoing line then goes to the sediment bowl.

There is another outlet on the fuel tank near the bottom on the in side of the tank with a spliced hose .

This runs to the fuel filter where I'm pointing to. That spring clamp is not tight ar all and the hose can be moved easily.

I have a JCB operators manual and they don't even show that line oe outlet even being there.

The original lift pump it still on it but only has one line still there. It's a hard line and I'm asssuming it the one of the hard lines going to the filter block with the bleeder. I can not see to verify, but I don't see a plug on the missing line port.

Why wouldn't you use the lower tank outlet to feed the pump?

Can anyone shed some light here or have a parts manual that would clear this up? I can't find any info on line.

 

[Billrog]

I'd be cleaning up that motor around where I had to work , easier and less chance of contamination.

 

[Delmer]

The fuel supply coming off the top is not unusual at all, and the return coming in the side is common also. Typically the suction supply will be larger than the return. If it works, I wouldn't worry about it.

 

[Kevin Foust]

Got everything rerouted and out of harms way. Bled it out and started it up. Left it sit overnight and restarted up this morning so it is fixed. Thanks for all the hand holding. LOL