Advise needed on CB pump malfunction, Dieseltech and others

Good morning,
It seems that I need some help. I bought an injection pump in the US for a friend and it got shipped to France. It was sold as a rebuilt. It took long time to get the 4020 where the pump could be assembled. The pump did not look like a rebuilt, more than an old shelve item that someone did paint. Upon testing, we found that the solenoid was bad (would not clck), then we found that the tractor would barely start with a ton of smoke. Injectors are brand new original Stanadyne.

Then the pump as swapped with a CB from a 4520, tractors is running very well with ton of power then. So we are sure cupright is the pump.


Pump get shipped back (carried in suitcases by people visiting US tractors shows). We had to pay for another rebuilt at same place that did it (or did not do it first place), and we got the pump back.

Now, we got it tried out. Tractor is starting very well, but it sounds like it is missing a cylinder. Power and throttle reponse seems to be lacking a lot compared to the 4520 pump. Also, the rpm are not going to 2500, only 1900. Tractor is running with a small tank of fuel to make sure the supply system is not getting us.

Yesterday, the eveness of the flow was checked by putting clear tubes with plugs at the end of the injectors lines to collect the fuel while tractor was crancked, then the same thing was done with the injectors dumping into a glass. It was found that the flow was fairly even. The injectors where poped checked and are at 215 Bars all even.

What could cause the engine to "miss" at higher RPM?
Is it possible that the rebuilder forgot to check and set:
- Transfer pump pressure at full delivery
- Automatic advance adjustment
- Governor adjusting screw (If I understand right the SM2045, only way to adjust that one is with the stanadyne gauge?)
- Roller to roller dimension
- Full throttle stop

Also, if tranfer pump is worn, the fact that we are running the tractor on a bottle of fuel and not with the supply pump is making it worse?

Lastly, is it possible to get access to the smoke screw by removing the cam advance pin, while pump is at 90d from timing position?

Thanks,
Frdric

You will need to get the supply pump feeding the filters and injection pump as it's supposed to be, then see how it runs. Low or no inlet supply pressure WILL upset the pump advance curve, and could possibly create a 'missing' sound. Best place for that pump is the trash can, and put a JDB pump and lines on it. On two tractor drives this year a fellow had a nice 4020 with the CB pump still on it with a chrome straight pipe. Sounded like crap when it ran when compared to other 4020s with DB/JDB pumps..

The fuel shut-off solenoid never "clicks" on a CDC or CBC pump.

Uneven fuel distribution is nearly impossible since this is a distributor-type injection pump.

I would check the fuel-injection timing at high RPMs. You can stick a clear plastic timing window on the pump and check it yourself (if you
have the Stanadyne window). Or - just manually advance the pump by loosening it and turning it and see if it runs smoother.

I doubt anyone can "rebuild" a C model pump. Patch up, paint and sell as "cleaned and tested", yes.

The trouble, and cash you have wrapped up in this pump would have easily bought you a JDB style pump n lines. Stop the pain and replace it. I have swapped out 3 this year. You can get a JDB with lines for 1000-1200 bucks. The pump you have was a bad idea from the beginning. If it wasnt it would still at least have replacement parts available. Al

Bad idea or not, some of those pumps greatly outlasted the D series pumps.

According to Stanadyne, support for the C pump was dropped because it was limited to smaller engines with relatively low output. So the D took over. How true that is, not sure if anyone ever knew. Corporate decisions are rarely made by one person.

I would not assume just because some design somewhere is dropped, it has to be because it was flawed. Lots of great stuff no longer made.

If I was working on your tractor - first thing I would do is pull the JD-270 plastic timing window out of my toolbox and check your timing
advance. One nice thing about most of the older Deere spec Stanadyne pumps is they have adjustable timing advances that the owner can do
on a running engine.

If you cannot find a timing window - next best thing is just manually advance the pump and see if it smooths out at high RPM. We had to
fix many that way and not just with Standayne pumps. 2940s with CAV pumps were know for high speed skipping unless be bumped up the
timing.

One other option is to get your hands on a diesel timing-light adapter. I have one but they are not real common anymore.

It is also good to know if the skip is on all cylinders or just one. A skip on just one is rare but it is possible with a bad lobe on the
cam-ring. When we had a tractor with a high speed skip - and were not sure if it was all the cylinders or just one? We'd pull off the
exhaust manifold and let the tractor get cold. Then start it and rev it up. White smoke would come out the bad running exhaust port. If
just one port - they you know it is just one cylinder.

As the other guy said, you would of been way better off finding a used conversion pump and lines with a D series pump.

(quoted from post at 06:18:23 09/22/19) The fuel shut-off solenoid never "clicks" on a CDC or CBC pump.

Uneven fuel distribution is nearly impossible since this is a distributor-type injection pump.

I would check the fuel-injection timing at high RPMs. You can stick a clear plastic timing window on the pump and check it yourself (if you
have the Stanadyne window). Or - just manually advance the pump by loosening it and turning it and see if it runs smoother.

I doubt anyone can "rebuild" a C model pump. Patch up, paint and sell as "cleaned and tested", yes.

Click to expand...

Fuel shutoff does make a very small sound that you can hear only if you take the wire off and bump it. A soark shoumd also occur.
As far as the pump I agree, but Cb pump are more reliable and original. Yes at low idle they rattle, but in France we have so many 1969 tractors that it is the normal sound.
Thanks for the advise about the fuel supply pump, I will yry that.

And I can tell you the invoice say Rebuilt. I ask the seller where they are finding parts?
We have brought few pumps from Spencer fuel and Columbus diesel with very good success on old Cb pump. They came back running like new.

Sorry you got gypped with that cb pump.they were
mistake number1 .many mechanics reported trouble
deere should have listened to and recalled every
cb pump and installed the b pump