941 injector pump

[Lee Tho]

I am working on a 941 diesel I am getting plenty of fuel to pump but nothing out to injectors what is the easiest way to find out if pump is turning ?

 

[agjim]

Remove the two screws from the timing window on the side of the pump. There should be a scribe mark showing on one part so you can make a mark on the part that mates the scribed part. Turn the engine and see if your scribe mark rotates. If your mark rotates your pump should be turning.

 

[riveroadrat]

Get a friend to help pull start it. Make sure your filters clean and no air in the top. There is also a very fine mesh screen filter inside the pump where the fuel line goes in, 13/16 wrench size. Scrape around it and spray it good with starting fluid before removal. you dont want ANY dirt to go in that hole.

 

[Al Baker(pumpman)]

you can almost bet the plungers and metering valve are stuck. If this tractor has set any length of time this just happens today with ultra low sulfur diesel and made worse by states blending soy diesel with fuel. I average about 2-3 stuck pumps each month. VERY VERY common problem. Best option is to pull it and have it resealed. Most Roosa pumps that have any age to them are due for a flex ring replacement anyway. Reseals are not terrible expensive. Shy away from anyone who is really cheap, or really expensive. Call around and price check and ask questions. If you are comfortable enough to use a computer to ask for advise from someone outside of your area, then be comfortable to send your pump away to be fixed. Don't just use a shop that is the closest. A reseal should cost 375-450 bucks. Be careful of the "Bubba or Jrs." that have a repair video or old service book and say they can do this. After they have worked their magic You can almost bet most times it never runs or starts as good as it could, or should. Get it done right and you will be happy with the results. Al

 

[cloydb]

you can almost bet the plungers and metering valve are stuck. If this tractor has set any length of time this just happens today with ultra low sulfur diesel and made worse by states blending soy diesel with fuel. I average about 2-3 stuck pumps each month. VERY VERY common problem. Best option is to pull it and have it resealed. Most Roosa pumps that have any age to them are due for a flex ring replacement anyway. Reseals are not terrible expensive. Shy away from anyone who is really cheap, or really expensive. Call around and price check and ask questions. If you are comfortable enough to use a computer to ask for advise from someone outside of your area, then be comfortable to send your pump away to be fixed. Don't just use a shop that is the closest. A reseal should cost 375-450 bucks. Be careful of the "Bubba or Jrs." that have a repair video or old service book and say they can do this. After they have worked their magic You can almost bet most times it never runs or starts as good as it could, or should. Get it done right and you will be happy with the results. Al

I have a 941 D that runs great for a few minutes then dies. its cranks right back up. its like its not getting enough fuel, All the filters and screens have been replaced or cleaned. All the fuel lines have been replaced. Got any ideas. The tractor does site alot, I use off road fuel. . I thought maybe water but looking at the fuel in a glass jar it looks ok.

 

[used red MN]

Hello cloy.., welcome to YT! When you tack on a reply to an old post most times you don’t get the same response as you would have by just creating your own post. This forum had a complete software change at the end of last year and I requested the moderators to include a note that triggers when someone attempts to reply to an old post warning them of this dilemma, it fell on deaf ears. Unfortunately Al Baker quit posting here in September 2023, so he will not reply here. It sounds like you have went through the fuel system pretty thoroughly. My only question is does the fuel flow well out of the line that comes from the tank and supplies the fuel filters? Sometimes a fuel system is verified to flow at one point and later debris finds its way into an opening and plugs it. This can fool you because in your mind you fixed or checked that already. I am not really familiar with Ford tractors at all I use factory parts diagrams to get an idea of the layout of machines I am less familiar with. Per the diagram for your tractor you say “glass bowl” shows no water, I don’t see that in the diagram. I do know of a filter set up that uses glass bowls and there is a trick to those that can cause your issue. You would have had to used Wix/NAPA brand filters to encounter this problem. In this case an oring gets placed out of position and blocks fuel flow. This link to an old YT post explains it, look at the 2nd pair of photos from the right. Filter info post
Beyond this I can’t help you. There is another posting member here that has an injection pump repair business a posts as Dieseltech. There is a possibility he may chime in here later or in the morning. During the summer he is an avid participant in “tractor drives” so he may be away on one this weekend. If he doesn’t you could contact him by a “Private Message” which is initiated from the “letter” icon at the top. Click it and choose “Start Conversation” then in Recipients type Dieseltech, when you type the t it should pop up to be selected. The rest is self explanatory. Good luck!
I will add you will probably get some replies from some Yahoos on here who are answering Lee Tho’s original post. Some on here only feel the need to read the first post in a thread and don’t look at the dates and throw there 2 cents worth of bla-bla on.
Good luck!

 

[used red MN]

I see @Dieseltech, is posting right now. See if this works. DT, have any suggestions for this gentleman. I am not sure if loosening the timing cover plate to relieve housing pressure also applies to CAV pumps any thoughts. I think you have clued me in on this before I will have to wait for your response and burrow it deeper in my grey matter.

 

[Dieseltech]

I see @Dieseltech, is posting right now. See if this works. DT, have any suggestions for this gentleman. I am not sure if loosening the timing cover plate to relieve housing pressure also applies to CAV pumps any thoughts. I think you have clued me in on this before I will have to wait for your response and burrow it deeper in my grey matter.

Loosening the cover does not apply to CAV DPA pumps, only to Stanadyne/Rosa pumps like his tractor has. I’ve been in Wisconsin this week on a drive.

 

[used red MN]

Cloy, it looks like I didn’t investigate the parts diagrams close enough. Many Fords used the CAV pumps. But your tractor has a Roosamaster pump. What happens to them is they have a flexible plastic shock cushion ring that over time gets brittle and breaks to pieces. The pieces clog the return outlet from the pump. Pressure builds in the housing which does not let the pumping plungers move out to load with fuel so they can’t pump. A trick to verify the issue is to loosen the rectangular timing plate that has the two screws in it when the tractor is dying, so fuel leaks. This drops the housing pressure and the engine keeps running. If this proves out unfortunately it means the pump needs to be rebuilt. In which case I would recommend you contact Dieseltech, and check what his price will be to rebuild it for you. Many on here send pumps to him due to his economical charges and high quality work. He is in Indiana BTW. Now that he has posted here you can start a PM conversation with him through his profile on the left side of his reply.

 

[cloydb]

Hello cloy.., welcome to YT! When you tack on a reply to an old post most times you don’t get the same response as you would have by just creating your own post. This forum had a complete software change at the end of last year and I requested the moderators to include a note that triggers when someone attempts to reply to an old post warning them of this dilemma, it fell on deaf ears. Unfortunately Al Baker quit posting here in September 2023, so he will not reply here. It sounds like you have went through the fuel system pretty thoroughly. My only question is does the fuel flow well out of the line that comes from the tank and supplies the fuel filters? Sometimes a fuel system is verified to flow at one point and later debris finds its way into an opening and plugs it. This can fool you because in your mind you fixed or checked that already. I am not really familiar with Ford tractors at all I use factory parts diagrams to get an idea of the layout of machines I am less familiar with. Per the diagram for your tractor you say “glass bowl” shows no water, I don’t see that in the diagram. I do know of a filter set up that uses glass bowls and there is a trick to those that can cause your issue. You would have had to used Wix/NAPA brand filters to encounter this problem. In this case an oring gets placed out of position and blocks fuel flow. This link to an old YT post explains it, look at the 2nd pair of photos from the right. Filter info post
Beyond this I can’t help you. There is another posting member here that has an injection pump repair business a posts as Dieseltech. There is a possibility he may chime in here later or in the morning. During the summer he is an avid participant in “tractor drives” so he may be away on one this weekend. If he doesn’t you could contact him by a “Private Message” which is initiated from the “letter” icon at the top. Click it and choose “Start Conversation” then in Recipients type Dieseltech, when you type the t it should pop up to be selected. The rest is self explanatory. Good luck!
I will add you will probably get some replies from some Yahoos on here who are answering Lee Tho’s original post. Some on here only feel the need to read the first post in a thread and don’t look at the dates and throw there 2 cents worth of bla-bla on.
Good luck!

Thanks I will repost properly. I appreciate your prompt and informative responce.

 

[cloydb]

Loosening the cover does not apply to CAV DPA pumps, only to Stanadyne/Rosa pumps like his tractor has. I’ve been in Wisconsin this week on a drive.

It does have a Stanndyne/Rosa Master pump. My return flow seems to be good but I will try loosing the plate to see if it changes anything. Thanks. Can you send contact info.

 

[used red MN]

It does have a Stanndyne/Rosa Master pump. My return flow seems to be good but I will try loosing the plate to see if it changes anything. Thanks. Can you send contact info.

The pump “has” to return fuel or as said it will not pump fuel to the injectors and the engine will die. So you will either have some amount of return flow or a non-running engine. Check your PM envelope icon at the top for the contact info.

 

[cloydb]

Loosening the cover does not apply to CAV DPA pumps, only to Stanadyne/Rosa pumps like his tractor has. I’ve been in Wisconsin this week on a drive.

 

[cloydb]

So your diagnosis is correct. What would you charge be to rebuild? How do I contact you?

 

[used red MN]

At the very top off to the right is an envelope icon should have a 1 on it or mark maybe more if someone else sent you a PM, click that. I tell you what to do in my message to you.