CAV DPA injector pump - no fuel to injectors after bleeding

[mungus]

Thanks, unfortunately STAR don't list one for my model. Yes saw the key. Timed the engine to TDC and removed the little cover and took a photo of the timing letter next to the circlip before I removed the pump. All good.

Options wise I have found a FIAT/NEW HOLLAND dealer recommended CAV repair shop about 40 mins from me, to look at my pump. In business since the 1930's so should know a thing or two...

Alternatively another old CAV repair shop in the next state over is selling reconditioned ones (with new heads), for around $900 USD. However they are listing one for my FIAT 780 has a different suffix, which made me wonder if Delphi have a cross reference table for their pumps? Mine is an 3342-F150 and their listing for a FIAT 780 is an 3342-F570. One Italian website selling pumps says that suffix fits a later 780 and early NH. Motor code is 8045-16, whereas mine is 8045-04. They look the same and are on almost identical motors. Call me a chicken, but without a CAV DPA document saying so I'm not putting down that kind of money.

I have both 1976 and 1979 FIAT service manuals and both list the F150...

Anyway I'll have a chat to the local shop on Monday and see what they think. I'm still thinking it must just be something jammed in a gallery or whatever, as it worked so well beforehand and nothing looks worn out etc inside. Anyway time will tell. Thanks for the help.

 

[thepumpguysc]

The 570 is the base pump the 150 was made from.. the fuel output is alittle higher than the 150.. 570=51mm & 150=46mm/st.. 10% higher.
Which is no big deal & you'll probably like it.. BUT the advance is only 4* as where the 150 is 8-9*..
YOU COULD get the pump, remove the advance cap, 7/8 wrench & remove 3-4mm worth of shims.. & be done..
OR get a shop to recalibrate it for you, which costs about 200.00..
Everything else is the same..

 

[thepumpguysc]

BTW> the Fiat # for the pump is>> 771050 & the Leyland # is>>AAU490.. hope this helps.. TPG

 

[mungus]

Thanks TPG, that's great info on the timing etc. Indeed that's a useable option with minor tweaking. A bit more fuel on the hills when pulling a load might be nice.
Yes that FIAT PN is confirmed from the service manual. Nice to know another manufacturer used it too. Might help with web searches. From the feedback I've received from a couple of suppliers it seems that PN is becoming a bit rare, so if I can source a 2nd hand spare in reasonable order, I might just do that.

BTW I've attached a couple of excellent video links here. I looked at quite a few before I settled on these as being the best for a layman. Might be of use to others seeking to understand the workings of CAV rotary pumps. The old English CAV B&W one really is an excellent introduction, with lots of cutaways and nice slow explanations. Very good grounding IMHO. After watching them and referring to my own I really felt like I had a basic understanding of how it works.

https://www.youtube.com/watch?v=kqDBMLB7jcY&t=515s

Be the Fuel.wmv - YouTube

I'm now almost certain the problem with mine is head related. Probably a blockage in a gallery downstream of the MV. Anyway I may post an update when its all resolved. I imagine this thread may help others as these CAV DPA pumps are employed on so many older tractors.

 

[thepumpguysc]

When you took the pump apart, did the rotor spin in the head?? if not, its seized up..
Inorder to remove the transfer pump rotor from the back of the pump.. the part the blades ride in.. to inspect the head rotor, you'll need to make a special tool..
A 15/16" socket will fit nicely over the tp rotor.. try it.. now, drill a hole across the socket & install a roll pin that will fit between the slots in the tp rotor.. The closest you can get to the bottom of the tp rotor, the better.. more "meat" to keep from breaking the rotor..
& IT WILL BREAK.. do not try to use a screwdriver!!!
The actual Delphi tool costs 80.00 but 1 can be made for about 6.00.. after loosening the tp rotor, inspecting the head&rotor & pumping plungers.. the tp rotor MUST BE TORQUED TO 65 INCH lbs.. good luck..

 

[mungus]

Thanks. Good to know the torque setting, as that useful data can't easily be found on the web.
But no it wasn't seized. In fact I was turning it port by port to align the holes, and blasting filtered air through to see if any gallery's were blocked.

Anyway without a test stand there's not a lot more I can do, so I'm dropping it at a shop today. $$$

Thanks again.

 

[thepumpguysc]

Sorry we couldn't fix it via the web.. I hope it doesn't cost you toooooo much.. post back & tell us what they found.. TPG

 

[Ford19488n]

I have a similar problem. I have a 1970 Ford 2000 with the CAV pump. I just rebuilt it with the kit and when I put it on the tractor without the fuel delivery tubes and cranked it, squirts of fuel come out of the holes. Once I put the tubes on there that the injector lines connect to there is barely a dribble out of the tubes and just some bubbles. There is some steel sleeve it looks like in the fuel delivery tubes. Is this normal for these to be blocking the fuel that much? I wanted to post the question to avoid the hour drive and cost for them to bench test it and tell me "its fine, that's normal..pay the cashier $$$$$$ on your way out". Thanks for all the great information on here.

 

[raymond ridge]

Hello, I am having the exact same problem with my CAV DPA pump that you had. Did you get it resolved? I resealed my pump and cleaned everything completely, but I just can't get fuel to pump out. If you got yours going, please let me know what you did. Thanks.

 

[thepumpguysc]

Ray.. the only thing I can suggest is MAKE SURE you engaged the shut-off bar w/ the shut-off shaft..
& that you put the spring back in THE EXACT SAME holes it came out of..
1 more thing>> how did you remove the gov. plate??>> the gizmo w/ the rod & fine spring hooked to the metering valve..
"IF" you took it apart, removed the small nuts, that's a problem..
"IF" you took it off as an assembly.. removing the 2 studs & the small screw in the center.. that's OK..
The pump doesn't pump much fuel.. so IF your getting dribbles from the LOOENED INJECTOR LINES.. & NO AIR.. tighten them up & give it a go.. TPG