Somebody is feeding you bad information. CAV is a better quality injection pump - period.Stanadyne/Roosmaster was the original and is the first rotary pump used by Deere ca. 1960 on 1010s and 2010s. CAV and Bosch purchased rights from Stanadyne to copy it with some improvements and use it only overseas. Later, some of those aggreements changed a bit. Any of the pumps are designed to inject a certain amount of fuel at cranking speed - and it makes absolutley no difference if it's a Stanadyne or CAV. What is the difference is which one wears first and gives problems. A cared for CAV will outlast the Stanadyne. Now, 2840s nad 2940s were some of the worst starting diesels Deere ever sold - we sold them new and had enless problems with them. Some old 4020s started at 10 degrees F with no heat or ether. We had new 2940s that wouldn' start at 40 degrees F. Deere had a long check-list to things to do to them - when new - in an effort to make them start as good as an older 2010s, 2020s, 4020s 4030s, etc. I can guarantee you that your tractor has had many things done to it since it was sold. Some of the original "fixes" that rarely worked were - new transfer-pump blades in the CAV injection pump, advance the static timing 2 degrees, thinner head gasket, plane cylinder head to get valve-in-head depth .025" and .040", hydraulic pump destroker, and new graded pistons with higher top rings. Kind of hard to tell what the story is now with your tractor - but I guarantee you the make of pump has absolutely noting to do with it - and anyone that told you that is clueless. Some of the best starting tractors we ever sold were the 50 and 55 series with CAV pumps. But, the improvement was not because of those pumps, it was due to closer assembly and machining tolerances. I will also mention - that at the same time of the starting problems with the 40 series ag tractors, we had the same cold starting problems with industrial stuff - like 350C and 450C crawlers - and they ALL had Stanadyne pumps.
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