[brian_b]

Is it possible for my fuel pump to hum like normal but have failed? I'm not very experienced with fuel pumps.

I was mowing at full load when my 322 abruptly went dead. No fuel coming out of the hose into the carb. But the fuel pump humms like normal when the key is in “run”. I can’t think of what else it would be. I just want to make sure I’m not missing something else before I go to Napa and spend $48 for a replacement, per Chuck’s very helpful thread here:

http://www.wfmachines.com/discus/messages/335/107986.html

I recently replaced the fuel lines, tank screen, and fuel filter, so I doubt they are clogged.

Thanks in advance for any advice on if my pump is for sure dead.

 

[phil47]

Bump. No responses, eh?

How are you doing on this?

 

[knottyrope]

hose in tank could have fallen off

 

[chuckv]

Brian,

I have had two 322 tractors, a first year 1988 and a last year 1992 (still have that one) and neither pump would "hum" when the key was on -- rather they made a pulsing noise. If your pump is not pulsing/clicking with the key on it most likely is not moving any fuel.

Here is the fuel pump test from the TM1591:

Have you done this test?

Chuck

 

[brian_b]

Thanks for the bump Phil, and responses Knotty and Chuck.

The day after the original post I further isolated the fuel pump, and it was clear that was the problem. Down to Napa for Chuck’s part number, installed, and tractor ran fine—sort of.

First surprise is that the pump was clicking/pulsing very unlike the previous pump’s “hum”. After further thought, and Chuck’s #7624 post, I believe the previous owner said he had replaced the fuel pump, and I didn’t get the impression that he was very careful about specs, so who knows what kind of pump he had in there (but it had worked). So I have learned that the clicking/pulsing is the norm for this application, not a humming pump.

Second observation was during the 20 minutes to finish mowing lawn once the pump was installed (so the hose in the tank appears to still be attached, I replaced that last spring). Within a few minutes, the engine started to stumble and skip a beat every 3-5 seconds. My initial guess was that I got gunk in the carb when messing with the fuel system. I sprayed some gumout in there while running, and put some seafoam in the tank. Last Saturday I mowed again for 2 hours, still had the stumbling problem, but not as much. I also noticed that I could smell the exhaust more than typical, kind of like incomplete combustion? I’m not sure how to describe it other than just what an out-of-tune engine might smell like, maybe burning rich. So now I’m thinking that I might have a separate problem that is merely more noticeable now for whatever reason, the separate problem perhaps with the ignition system (coils, plugs/wires, etc…). My first thought would be condenser/points, but to be honest I haven’t had time yet to look up if this tractor even has points/condenser, or a different system. I don’t see points/condenser on JDparts. When I bought the tractor 18 months ago, it came with the tractor tech manual, but now I see that there is also an engine service manual and I don’t have that, so I’ll have to figure out where to get one.

I haven’t done the 7 oz/30 sec test yet. My tractor tech manual also has a second test to check for 2 psi, which I haven’t done either yet. I don’t think my tech manual is TM1591. It’s at home, my memory is dusty, but does a number like 2218 ring a bell to anyone? Anyone know what the difference is between TM1591 and the other manual that I have (which isn’t the engine manual)?

I really appreciate your help. I'll let you know as I find time to whittle away at the troubleshooting steps.

 

[trapperjohn]

Brian, Here's the other manual you will need. It is CTM12 and you will probably be able to get it on Ebay.

 

[trapperjohn]

Brian, I just glanced through the CTM-12 and there is nothing about the fuel pump in there. I guess because it is not attached to the engine, it is not a component of the engine. So, for the fuel pump, the TM1591 will be you best bet. The CTM12 is still a worth-while manual as it covers everything else on the gas Yanmar.

 

[brian_b]

Thanks for the number Ron. I'm intimidated to troubleshoot the plugs/wires/coils/points & condenser (or equiv)/carb/etc. without the manual, so I intend to get my hands on a copy.

 

[trapperjohn]

Brian, I just googled (John Deere manual CTM 12) and the first thing that popped up was the PDF of the CTM manual. Its free. I do have an extra hard copy of the CTM-12 if you can't find one elsewhere.

 

[phil47]

Ron - Could you post the link for the CTM manual? The ones that came up for my search required payment. Thanks.

 

[brian_b]

CTM12:
http://golftechs.us/Manuals/CTM12.pdf

I also found TM1591:
http://www.wfmfiles.com/download/manuals/TM1591.pdf

 

[brian_b]

Wow Ron, that made my life easy. Pdf saved. Thanks much for the link and the offer for the hard copy, I’d feel bad making it unavailable for someone who might not have the pdf.

My tractor manual is TM1277, rev Jan 1988. My 322 is a 1989. However, then I found a different forum that said that TM1591 is a better version that JD dealers were instructed to use as a TM1277 replacement. Now I have a Jul 1995 copy of TM1591, even though I assume my TM1277 would still be adequate, for my tractor hasn’t changed since the time when TM1277 was deemed adequate.

Now that I have CTM12, I see that all along my TM1277 has had all the info and troubleshooting for the ignition circuit. So, I can start from there. I see no points/condenser, instead electronic ignition.

 

[phil47]

Thanks, Brad. That was helpful. I need to explore this site more thoroughly. That one had blown by me.

 

[phil47]

The link to the manuals on this site is not very obvious. I would not have found it without Brian's post.

That is valuable info. I just spent $97 for a hard copy for a manual for the 316 I just bought. I've always like hard copies, but now that I have a pdf copy, I'll try printing out the pages I need to trouble shoot and electrical problem and use them as a check sheet on a clipboard. It should be much easier than handling the whole, bulky manual.

I did find the thread on sources of manuals in the FAQ section, but there is no post with the link to the WFM site.

 

[brian_b]

If I'm not mistaken, the wfmfiles.com website is a totally separate entity than www.wfmachines.com. Others may know the history of the two names better.

 

[craft57]

Phil Peterson : …. the problem you described above, of exhaust smelling Rich ? …. If this odour was NOT present before you replaced the fuel pump, then I would suspect that : Either the NEW Fuel Pump is producing Too Much fuel pressure to force the Float Needle down to create a Flooding Rich Condition or ??? with the New Fuel Pump producing Proper Pressure the Float Needle in the carb is worn to a point of not sealing correctly anymore maintaining the proper float level then Flooding the Engine ….. ???? …. Just a thought for you to consider, I would highly doubt that your Electrical system is failing as a coincidental problem ??? ….

Check Your Spark-Plugs TIP COLOR ! …IF they are ALL A DARK BROWN Chocolate Color then It's running TOO Rich ….. after this condition happens, this Will be a sure way to determine if you have a Flooding condition happening , Also does this stumbling of the engine happen in WOT (wide open throttle) under load … if it clears up at WOT then I would for sure Suspect the Float Needle …..

Hope this might Help you narrow down your issue ….. Cheers …GK

 

[brian_b]

Gary,
I assume your post was for me. I also suspected the fuel pump, but wasn't sure why that would cause the engine to stumble at WOT under load. To be honest, I haven't run it much without load except initial warm-up, when it doesn't stumble, maybe because it's cold, or maybe because it's no load. I'll make more observations.

I have "fixed" 2 carbs in my life enough to know that I'd rather leave this one alone until I absolutely have isolated the problem to the carb. I haven't checked plugs yet, another thing on my troubleshooting checklist. Could dark brown chocolate also be caused by weak spark with the proper fuel ratio?

Thanks,
Brian

 

[craft57]

Sorry Brian B it was ….. was looking at your name and typed out Phil's ….. Oh My ! …… another one of those something else was on the brain Day ! …. LOL ….. OOP's Sorry but glad you caught it Too

 

[craft57]

Brian B : Hmmm ? …. With a weak spark it would create more of a fouling condition in my opinion ……. But without not being there and not seeing/hearing it run it's kind of hard to try and diag your problem, this is why suggestions hopefully lead to a solution ….. Having never seen a 322 set-up , Chuck would be the Man to clarify if this GT had Points and a Condenser ….. My thought lead me to believe that by the date of your machine that it is a CD ignition system and Not Points, that being said CD ignitions either work or they don't eliminating the DA guessing with the old Point/condenser engines had …. LOL ….. Check the plugs and go from there, maybe replace them anyways rather safe than have to second guess … if you haven't done that in a while maybe they're burned out ??? …… Cheers …. GK

 

[chuckv]

Brian and Gary,

The 322 has a Yanmar 3 cylinder gas engine that uses a transistor ignition -- there are no points. The crankshaft rotation is sensed by magnetic pickups on the flywheel called Pulsars, which in turn trigger the transistor module to drive the primary windings of the three individual spark coils. Here is the wiring involved...

The problem being described above in Brian's post of the 24th does sound like it is most probably a fuel delivery issue -- and missing at full throttle but smooth running at lower speeds points to fuel starvation at higher delivery rates. This could be a plugged orifice in the carburetor from a burst of crud when the lines were opened and the pump replaced, so check the passages and jets...be sure to NEVER use a wire or other probe to clear the orifices -- just cleaning solvent and low pressure air as instructed in this excerpt from the manual:

Check the float level setting as well, per this manual excerpt:

I will send you some more info that is too large to post here.

Chuck