Franklin 120 Porter CAV Injection Pump Issues

[c greenham]

Good Morning,


I have a problem with an CAV injection pump on my porter the engine is a Perkins 4.236.  The lift pump is supplying fuel to the injection pump but the injection pump isn't pushing the fuel to the injectors.  I have replaced/checked filters so this isn't the problem.

Anyone have any ideas what could have happened to it the pump, it spins well but not pressuring up fuel.

Thanks for your help.

[chevytaHOE5674]

Does it have a manual or solinoid for the shut off?

Are you sure that the shut off is moving to the run position?

[Satamax]

I start to know these a smidge. So, first thing to check, the electric solenoid, if there is one. Second, the filter at the banjo fitting between the injectors lines.  they're notoriously hard to bleed. Firt you bleed the fuel filter, then the body of the pump, the lower 8mm bleed, then the cap bleed, the higher 8mm bleed, then the injectors. Sometimes you have to try three four times, if there is lots of bubbles in the lines. I have replaced the mechanical pump, with an electric one. Makes my life easier. Check if the anti return valve (check valve) on the return line is not stuck open. Then, if azll fails, replace at least the cover's joints. There  is good tutorials about all this from an aussie guy on youtube. 

[newoodguy78]

I'll agree with what's been mentioned above.  Those pumps can be a real bear to bleed. I've got one one a Massey Ferguson tractor with the 4 cylinder Perkins in it, my only reservation with it is bleeding the system after a fuel filter change.
They are fairly simple pumps, rebuilt mine with the help of the local pump shop and I believe the same guy satamax is talking about.
One thing to watch if you pull the top of the pump off is the position of the spring on the end of the throttle shaft. There's an arm on it internally with three holes in it. Take note which hole the spring is in and make sure it's put back in the same place.
Also when removing the cover hold the shafts (throttle and shutoff) down as you lift the cover that way nothing gets out of place.
If you take the cover off that's the time to replace the orings at the very least.

[C5C Tree Farmer]

If air has entered the injector pump head it will not displace fuel until the injector lines are loosened. Crank the engine at wide open throttle until the fuel appears then tighten the lines and see if it will start. If the pump will not displace fuel with the injector lines loose and the fuel shut off is in the run position it is probable that something failed in the pump itself. If it was me I would remove it and send to a pump shop.

[EricR]

Bundy bears shed on YouTube.  If it has been sitting they have a plunger in the head that can get sticky.  These pumps are pretty simple to tackle yourself. There is no reason to be afraid to open it up if you are mechanically inclined.  If you don't repair yourself, around here it is cheaper to buy a new/rebuild then to pay a shop to go through yours

[c greenham]

The pump got a manual shut off.  The shut off or the fuel valve is not stuck, I can get fuel in the pump but it wont pressurize the injectors.  I have loosen the fuel line going to the injectors, no fuel coming out then bleeding.

Any help greatly appreciated.

[C5C Tree Farmer]

Most of the shops that repair injector pumps will walk a potential customer though the things to check out first before the pump is diagnosed as bad. This may be of some help to you as they will know where the problem areas are on a CAV pump.

[beenthere]

Lots of videos on CAV injection pumps.. some likely better than others.

Watched one the other day that was very informative and very well presented, linked here. An acquaintance sent a pump to this service center for repair and passed the name on. Getting past the intro helped to enjoy the rest of the video. Interested me to learn about so many detailed parts inside an injection pump, also my father was involved in designing injection pumps for the first diesel tractor produced by John Deere. Knew Roosa-Master and Stanadyne as household names when I was 5-10 years old in the 40's. 
@AreaDieselService DB2 Pump Rebuild for @C_CEQUIPMENT's JD455E Track Loader DB2435-4490 Stanadyne - YouTube

[barbender]

I don't even know what injection pump it had, but the only Perkins I've ever been around was the most miserable thing to get running again after it was run out of fuel. I've been around a lot of diesels that were run out of fuel, nothing approached what it took to get that thing reprised and bled.

[c greenham]

There is no air in the system, what would cause this pump to quite pumping fuel to the injectors?

Worked perfectly the machine was moving and it just shut off like someone pulled the stop lever.

Thanks for your help.

[newoodguy78]

Have you removed the filter /screen and made sure it's not plugged?
If that's not it sounds like it's time to pull the pump and do some exploratory surgery or take it to a shop.
Shutting down while running leads me to believe something internal let go or plugged up providing it didn't run out of fuel.
It's been mentioned several times but bleeding those pumps on Perkins engines are an absolute bear. No idea what the difference is but those pumps are run on older fords as well, completely different animal when it comes to bleeding them.
Had a white tractor with the Perkins in it with that style pump, nightmare to bleed

[barbender]

You can have fuel in the system, and no air. But have a blockage anywhere in the fuel system and it will act just like your shut off solenoid.

[Corley5]

Is the pump turning? Did a piece of the drive break?

[c greenham]

The pump is turning took the side cover off and it does rotate.  I also took did check the screen on the intake it wasn't dirty or plugged.  I have the pump off it don't look like there is any issue mechanically.  I have not taken it apart, that will be the next step.  

Just wondering what to look for?

[newoodguy78]

Look at the governor weight and veins of the motor. Might be sticking or broken somehow. 
There's lots of good advice being given, also a lot of how it works, repair type videos on these pumps. Have you checked any of them out?They certainly helped me understand how they work and what to look for. 

[Satamax]

The pump is turning took the side cover off and it does rotate.  I also took did check the screen on the intake it wasn't dirty or plugged.  I have the pump off it don't look like there is any issue mechanically.  I have not taken it apart, that will be the next step.  

Just wondering what to look for?

I have had a stuck past fully open metering valve.  Another thing you could look for, a stuck pumping element. 
The CAV Distributor Type Fuel Injection Pump Type DPA Construction & Operation - YouTube

[c greenham]

Good morning All,

Got the pump sent to the shop, they are to take it apart on Monday July 31, 2023.  I will let you all know what the problem is when they give me the diagnostics.

Anyone want to try and guess how much this will cost?

Hope you all have a good weekend.

[c greenham]

The shop is saying the pumps head and rotor is gone, it will cost $1750 to replace.

[Satamax]

The shop is saying the pumps head and rotor is gone, it will cost $1750 to replace.

By any chance, you haven't taken a pic of the pump's identification plate? Because it seems a bit steep. May be check dieselfresh on ebay

[leeroyjd]

The shop is saying the pumps head and rotor is gone, it will cost $1750 to replace.

Like Satamax said, check Dieselrefresh on ebay. I know nothing about them but price is about half.