AC 160 Injector pump

[acny]

I had been losing prime a few times so I changed the filter, checked fuel lines, bowls, transfer pump, etc. After changing filter I lost prime two more times, now I can't get fuel to the injectors.

I get good flow from the bottom bleed screw in the injector pump but not getting up to the injectors. Only get dribbles at the #3 injector and none at the other two. It also was spitting out unburnt fuel through the exhaust.

It seemed to lose prime or stall out when going up a steep hill. Tank is half full. Each time I got it primed, it ran fine for a day or so. Engine oil is clean.


Thanks,
WM in NY

 

[LAA]

Pretty much sounds like a weak injector pump, not enough fuel pressure to run under load. Getting fuel out of the exhaust could be a stuck or cracked injector but could also be from weak pump pressure and the fuel not being burnt. If the tractor has recently become hard starting that is another sign.

 

[acny]

Thanks, Do you mean that a weak fuel pressure would cause the injectors to not atomize properly?
Since I'm not getting fuel at the injectors that could be it if the injector pump had been getting weaker and finally quit. I'm going to check the blades at the rear of the pump and try again. I think I read that the CAV is a hard pump to prime? It primed OK before. I do worry about burning up the starter.

Thanks again.
WM

 

[LAA]

Maybe the pump was getting graudually weaker and it would run when not in a bind or working too hard but now it is too weak to put up enough fuel pressure with just the starter RPM's -- if that was the case you might pull it at a pretty good clip and get it fired off. If it started by pulling you would have another reason to suspect the pump. If you decide to take the pump off and get it checked I would reccomend pulling the injectors and checking them as well because bad tips could be another reason for fuel in the exhaust.

 

[acny]

LAA, Thanks, hope you're still here. I have no way to pull the tractor. Thought I would charge the battery and try again, It had been turning over fine, but just to be sure its fast enough.

However, maybe I should just take out the injectors and the pump and get them checked, then I know for sure. I have the IT manual and guess I can get the pump back in and timed without a problem.

Do you think that is my best move now?

Thanks,
Wayne

 

[LAA]

I read your post again and as far as I can tell you covered the bases and did a thorough job of checking where you were and were not getting fuel and the pump is still suspect. The fuel control valve could be stuck but that is internal and would have to be stuck with trash or shavings, so still means tearing the pump down. If I was taking the pump off I would mark the pumps position in relation to the adaptor plate scribe lines and snap a picture or draw a picture as well as mark it on the pump. When you remove the timing cover and the drive gear bolts mark the position and snap a picture, leave the gear in place if possible when you remove the pump. The good news is that basically the same CAV pump was used on many different brands of tractor and other machines so there are plenty of them out there and parts etc. are easy to get. In my opinion, injector repair places are like automatic transmission places, in other words, they charge an armm and a leg for their services because they can. It pays to shop around, even send it off if you are not in a big hurry. If a shop will not agree to look at the pump and give you a solid estimate then I would not fool with them, if the shop foreman says something like - I won't know what it needs till I tear into it, and won't give you a price just for diagnosing, like an hours labor or similar, then that usually means he is gonna stick it to you. I have seen injection services vary by as much as $2500.00 on big pumps and several hundred dollars on little ones. There is a place in Fort worth Texas that you can send it off to or at least call and get some price quotes, I got good deals from them in the past and the shipping is just a few bucks, Lonestar fuel in Fort Worth -- 1-800- 839-5734. What ever you do try to get more than one price because they will try to stick you up.

 

[acny]

LAA, thanks for your help. Was ready to pull the pump and have it rebuilt. Local rebuilders said no need to test it just rebuild it. Then I found a local mechanic who said, are you going to be around this afternoon? He came that day, and in 15 minutes had it running. He loosened the injector HP line at the pump along with other places as in the book and it has been fine since. Fuel was bad, replaced it also. Working fine now.

Thanks again, Wayne

 

[LAA]

I'm glad you got an honest man, its a damn good tractor otherwise though, ain't it ? I love my 160 because I was raised with one.

 

[acny]

LAA,

I have the 160 with a 460 loader and a 5020 for mowing, etc. Using the 460 to build a trail through the woods. It's great. doesn't seem to be stressing the machine at all. However I've lost my steering. Will check it out today, the wheel turns with no effect on the steering. Have you had any problems with steering?

Thanks,
Wayne