# Fordson dexta diesel injection pump help



## Fitz's Fordson (Aug 20, 2020)

I have, as near as I can tell, a early 60's (prior to April 1962 according to the service manual) fordson dexta with a 3 cylinder perkins diesel that I have been rebuilding for several years after I lost a bearing on the crankshaft. I have it all put back together but I am running into some issues getting the timing just right especially with the simms injection pump. I believe the problem is that I have the simms injection pump part number 957E-993101-A with a vacuum governor. I have come to this conclusion because the pictures in the manual match and there is a suction tube coming from the intake manifold to the diaphragm unit on the back of the injection pump. In the manual it states when attaching the gear to the drive gear adapter to use a socket and rotate the adapter until the timing line marked "S" for the vacuum governor pump lines up with the timing mark on the timing gear housing flange, and the adapter for the "minimec" injection pump with a mechanical governor has a timing line marked with a "TC". My adapter plate is marked with a "TC" which tells me that I have the wrong adapter plate for my injection pump? If anyone can offer some information to clarify this for me or knows where I can find the correct adapter or how to get the timing set it would be greatly appreciated!


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## Hacke (Feb 22, 2011)

Hello Fitz's Fordson, welcome to the forum.

Do the marks on your pump look like the marks in the attached picture?

Picture is a screenshot from Manual Part 4:





Tractor Manuals - Vintage Tractor Spares


Fordson Dexta/Super Dexta Workshop Manual The following manual is provided courtesy of Stefan Reigel and you may use and distribute it freely provided that you acknowledge it’s source and that you do not attempt to sell or make money from it. Manual Part 1 – Brakes and Wheels (472 KB) Manual...



tractorspares.ie




It covers only the early Simms pump.


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## Fitz's Fordson (Aug 20, 2020)

Hey Hacke, Thanks for your prompt reply! Yes from what I can see from the photo you attached they do appear to be the same. I am attaching some photos of my injector pump and the marks to better illustrate. Reading the manual you gave me access to (much appreciated and it is a bit more in depth than my current manual) seems to be the same procedure to attach the gear, from the engine section on the timing gears and the fuel systems section regarding timing the pump. I was trying to attach a picture but I cant do it as of yet but as soon as i can i will 

thanks again


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## Fitz's Fordson (Aug 20, 2020)

I think I got it I had to post them from my phone. Let me know what you see please 

Fitz


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## Hacke (Feb 22, 2011)

I do not see the mark on the right "wall" of the inspection opening. Clean that area, so you can see the mark.

How does it look with the gear on the pump, engine correctly rotated and the gear train timing marks aligned?

The "TC" line is top dead center and the lower line is the ~20° before top dead center that should coincide with the mark on the wall.


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## Fitz's Fordson (Aug 20, 2020)

Yes the mark is definitely there easy to see I just didn't get it in the picture and it is very clean, also that housing i believe is aluminum, so no issues there and all the timing marks lined up perfectly starting with the camshaft gear in the proper position with the third tappet in the highest position. I feel the biggest obstacle is that the adapter on the shaft of the injector pump that the gear attaches to with three set screws, is marked with the "TC" which is supposed to be at 20 degrees BTDC but that is for a "minimec" injector pump with a mechanical governor but my pump is the vacuum (pneumatic) governor model and needs to be timed at 26 degrees BTDC and the proper adapter is marked with a "S"?


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## Hacke (Feb 22, 2011)

I do not know about the Minimec, but if "TC" means 20° BTDC, the lower line should be around 40° BTDC. What is the use of that?

Was the engine running with this pump, before the renovation?


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## Hacke (Feb 22, 2011)

Maybe this pump is refurbished, or replaced? I see 2014 stamped on it, and the filter housing on the governor part does not look like on the old pumps. There may be parts that do not look like they did in the 50´s, and the manual instructions will be confusing.


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## Fitz's Fordson (Aug 20, 2020)

Hey Hacke Sorry I missed your last replies, yes this was the pump that was running this tractor before I had to tear it down. The good news is that I was able to get it running. I had also e mailed the simms injection pump manufacturer and they instructed me how to do a "spill test" on it. I believe you were on the right track as well because after performing the spill test and getting the spill mark on the flywheel lined up with the timing mark on the bell housing and when I got the pump dialed in I was just a little bit below the "TC" mark but well before the second mark that was 40 degrees before top dead center. Thanks for your help. But I am pretty sure that is the wrong adapter plate because when it is all said and done the timing mark on the actual gear does not line up with the timing marks on the other gears, it is just one or two teeth off.


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## Hacke (Feb 22, 2011)

Great news that it is running again!
I have seen some instructions for the spill test, was it very complicated to do?

Great service from Simms, by the way.


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## Fitz's Fordson (Aug 20, 2020)

It was not terribly hard to do, just rotate the pump clock wise mine has 3 lobes that it wants to fall into a certain spot, I guess one for each valve or port that the injector lines attach to. With the system full of diesel and primed slowly rotate it until you see the fuel come up through the port and that is where I tightened the gear down on to the adapter plate with the number 1 cylinder at 26 degrees before top dead center. I am pasting the instructions that simms sent to in an e mail also. 

A basic check is once you have bled the system and cranked over the engine, fuel will spit out of your deliver valve holders, number one is at the drive end, rotate the engine by hand and watch the fuel in the top of the delivery valve holder raise, and that is at point of injection, which should be 26 degrees before top dead centre, so the fuel should start to raise then, if not you will have to adjust pump to engine timing.

I was actually watching a car show and they happened to be working on an injection pump for a older mercedes and they were doing a "spill test" on it and they removed a spring from the top valve of the port to change from high pressure to low pressure but I didn't go that far and the gentlemen at a local diesel service place told me to hold my finger over the port to feel for the puff of air as well


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