Hello, I have a 2003 341 Midi-x and it started to lose power, like a plugged fuel filter. I changed the filter and it still would bog down if I did any heavy digging or 2 functions at the same time. I started poking around in the engine compartment and found one of the distribution valve O-rings was shot and leaking fuel. I replaced all 4 o-rings and put the injector lines back on. When I started the machine, the exhaust was black!! Like smoke you out of the yard black. I shut er down and did a little interneting. I read that I could find the problem by cracking the injector lines and when the problem stops, it would narrow down the cylinder that's having problems. I did this to find the last cylinder (of course) has the issue. When I crack the fuel line going to cylinder 4 the smoke stops, the high idle comes back to normal, but now I have a dead cylinder!! I replaced the injector for #4 with no improvement. Next I removed the lines again to see if the fuel coming from the other injector lines was comparable to what #4 was pushing. Somehow, #4 has around half the fuel as the others. I swapped the distribution valves between #4 and #1 to see if that was the problem and now #3 has no fuel flow. Also, now the fuel shut off switch will not kill the engine. I have to crack the injector lines to kill the engine. Please help!!! I'm starting to think that the injection pump is my problem, but I really don't want to spend another grand to find out that it wasn't the problem. Thanks!!
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So after extensive interneting, I think my problem lies in the delivery valves. I tried to set them to where they were, but I still don't have fuel coming out of cyl #3. Is this something that has to be bench set? Pull off the entire injector pump and bring it to a shop? Also on a Denso pump, is there any possibility that the plunger that sits under the delivery valve can turn or is it held in place with the rack and pinion? Any help appreciated!!
It sounds like you went a little deep into the pump and sadly, a shop will need to re-set it for you.
The elements in the pump rotate to alter the amount of fuel being delivered. If when you pull the delivery nozzles out the element comes out too, it messes with the position it sits in relation tothe rack. The rack moves all 4 together, so if one is out, it will put out more or less fuel than the other three. You need special gear to ensure you get them all adjusted correctly
That's what I was afraid of.. I guess time to bite the bullet and pay someone else to work on my equipment. Grrr... Thanks Tazza!It sounds like you went a little deep into the pump and sadly, a shop will need to re-set it for you.
The elements in the pump rotate to alter the amount of fuel being delivered. If when you pull the delivery nozzles out the element comes out too, it messes with the position it sits in relation tothe rack. The rack moves all 4 together, so if one is out, it will put out more or less fuel than the other three. You need special gear to ensure you get them all adjusted correctly
I know it's not what you wanted to hear, hopefully the job is simply an adjustment, so the price shouldn't be too bad.
I brought the pump to a local guy working out of a Quonset (best kind, imo), and he said even by changing the O-rings on the delivery valve stems will throw off the injector pump. So, basically if you loosen anything deeper that the injector lines off of the pump, you will have to bring in the pump to have it calibrated afterwards. Hope this helps someone else down the line! Thanks for the help!!
It's a shame they didn't design it better, but at least you now know and can get it adjusted to get it right again.
Thanks for the tidbit of info...I did read somewhere, long ago, that the pump is shimmed for fuel flow, so even a 1/32" makes a difference...
