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New to the forum (although i have owned gators for quite a few years). I recently purchased a 2011 825i from an auction. It was a decent deal considering options and condition. The engine is running rough and maybe misfiring. I have been going through the systems both to familiarize myself with the current state of each and also to find any potential problems. This is my second gator so it can be a long term project. I checked fuel pressure last night (inline just after the fuel filter, which is new). I am seeing about 40 psi from the fuel pump (a little low - i have the service manual) but when the pump stops the pressure immediately drops to 20 psi and slows leaks down to 0. Is this normal? Is there a check valve in the fuel pump/system somewhere that should be maintaining pressure? I know the fuel pressure is important for the performance of these engines. Thanks in advance for any help you guys can be. Look forward to from learning the folks on this forum.
 

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New to the forum (although i have owned gators for quite a few years). I recently purchased a 2011 825i from an auction. It was a decent deal considering options and condition. The engine is running rough and maybe misfiring. I have been going through the systems both to familiarize myself with the current state of each and also to find any potential problems. This is my second gator so it can be a long term project. I checked fuel pressure last night (inline just after the fuel filter, which is new). I am seeing about 40 psi from the fuel pump (a little low - i have the service manual) but when the pump stops the pressure immediately drops to 20 psi and slows leaks down to 0. Is this normal? Is there a check valve in the fuel pump/system somewhere that should be maintaining pressure? I know the fuel pressure is important for the performance of these engines. Thanks in advance for any help you guys can be. Look forward to from learning the folks on this forum.
Have you replaced the fuel filter and retested ? According to specifications your pump is almost 5 psi below spec. Additionally have you looked for kinks or leaks on the fuel line ?
 

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Discussion Starter #3
Filter is new. Fuel line is new. No leaks that i can find. I am just unclear on how the fuel system is supposed to work (stay pressurized or not). There is nothing about that in the service manual, as far as i can find. I havent read all 490 pages yet, but im not too far off. Either way it would probably be a good idea to get a new pump since it is off spec. However i am trying to allocate my available funds to immediate problems if possible. Any more thought or suggestions would be appreciated. Thanks
 

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I believe the pump will drop in pressure although, leaking down to zero does not seem good ?
 

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Try looking online at Power Sports Nation in Norfolk Nebraska, they’re a large used part warehouse for UTV’s
 

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The fuel pressure specs are 45.6 to 50.4 PSI. The tech manual states to replace the Filter, check for leaking/kinked hoses and if your still have low pressure it is the fuel pump/regulator in the tank. As far as leak down the manual doesn't specify, but if you ever changed your fuel filter without disconnecting the pump and running the engine you will find out that the system maintains pressure, not sure how long but I can attest to at least 10 minutes. Leak down test should be performed at approx. 85-95 PSI, any reading below 25% is considered normal. The compression test should be approx. 180 PSI but since your readings were so low in every cylinder and your leakdown test was within the acceptable range I would suspect one of your tests in skewed.
 

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Thanks for the reply. I suspect my compression tester guage is off. I am getting a new one and will be testing again after verifying the new guage is working appropriately (connecting to a known source of pressure for testing). The leak down tests looked fine. I will be replacing the fuel pump. I have found an aftermarket one made by quantum fuel systems. The advantage with that one over oem (other than price) seems to be a lifetime warranty and it is designed/rated to handle ethanol fuels. Has anyone tried this one or a similar one with good results? The pump in my other gator is oem and has never caused me problems, but has a lot fewer hours on it. Thanks
 

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Sounds like a plan.

My 825i ran rough and sounded like it had a miss and after testing everything I could and finding nothing I was told to replace the injectors. The new JD injectors helped a little but did not solve the problem so I continued to troubleshoot off and on for about 6 months with no success. I finally broke down and took it to JD for testing, they hooked it up to their computer and ran it through the entire testing process (I stood there and watched the tests) and could not find anything wrong (according to the computer everything was running okay). I told the tech and service manager something was wrong because I can hear the miss and they agreed but they had no idea what the problem was, they recommended changing the injectors. I explained that I already changed them and they said that the only thing on the engine that isn't tested by the computer are the injectors and there are no codes in the ECU so it must be the injectors. I tried to get new injectors replaced under warranty but since I had already used them they wouldn't replace them under warranty but would sell me a new set, I refused to buy another set of the Chinese junk injectors . I took it home and eventually ordered a set of injectors from (www.motormanfuelinjection.com), they offer a set of Bosch Injectors (not china junk) for the Gator for about 1/3 the price of the OEM's. They are a direct replacement for the OEM's except your need to purchase two bolts and 4 washers as spacers for the fuel rail (available at Ace hardware). After the Bosch injector install my machine runs like new.

I am not saying that your problem is the injectors, but if you test everything else and still can't find the problem it may be something to try.

Good Luck, if you have any questions let me know.
 

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Discussion Starter #10
Thanks! That is great insight. I have a friend of a friend who is a john deere mechanic. He is supposed to meet up at some point and hook my gator up to his laptop. He didnt seem too confident that it would do any good, since I am also not throwing any codes. I have listened to the injectors with a stethoscope and they are all clicking, although that doesnt mean they are all shooting. I will give that link a look and get some on order. With over 2900 hours and 14000 miles they could probably use a swap anyway. I assume the bolts and washers are just to accommodate a slightly longer injector? Thanks again!
 

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Discussion Starter #11
Also, did you use the john deere part number to look up those bosch injectors? Or did you contact them and ask? Thanks
 

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Sounds like a plan.

My 825i ran rough and sounded like it had a miss and after testing everything I could and finding nothing I was told to replace the injectors. The new JD injectors helped a little but did not solve the problem so I continued to troubleshoot off and on for about 6 months with no success. I finally broke down and took it to JD for testing, they hooked it up to their computer and ran it through the entire testing process (I stood there and watched the tests) and could not find anything wrong (according to the computer everything was running okay). I told the tech and service manager something was wrong because I can hear the miss and they agreed but they had no idea what the problem was, they recommended changing the injectors. I explained that I already changed them and they said that the only thing on the engine that isn't tested by the computer are the injectors and there are no codes in the ECU so it must be the injectors. I tried to get new injectors replaced under warranty but since I had already used them they wouldn't replace them under warranty but would sell me a new set, I refused to buy another set of the Chinese junk injectors . I took it home and eventually ordered a set of injectors from (www.motormanfuelinjection.com), they offer a set of Bosch Injectors (not china junk) for the Gator for about 1/3 the price of the OEM's. They are a direct replacement for the OEM's except your need to purchase two bolts and 4 washers as spacers for the fuel rail (available at Ace hardware). After the Bosch injector install my machine runs like new.

I am not saying that your problem is the injectors, but if you test everything else and still can't find the problem it may be something to try.

Good Luck, if you have any questions let me know.
Thanks for sharing, do you know the part number from the company you purchased the injectors and the size of bolts and washers you used ? This information will help others when diagnosing and repairing their 825i.
 
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