ZD21 isn’t getting gas to injectors

Mattcade

New member

Equipment
ZD21
May 7, 2022
1
0
1
Albertville
Hey. I’ve got a ZD21 zero turn mower and it has been running pretty good, but yesterday I went to start it up and it started then died and won’t start back up. It turns over good and the glow plugs are only a year old. I replaced the fuel filters, fuel pump, and fuel hose yesterday but I’m still not getting gas. When I pull the return line off gas is coming all the way through, but when I loosened the injectors no gas was coming out. Could it be the fuel injection pump? Is it possible to just clean it to get it working or does it need to be replaced?
 

Dave_eng

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Lifetime Member

Equipment
M7040, Nuffield 465
Oct 6, 2012
5,108
926
113
Williamstown Ontario Canada
Hey. I’ve got a ZD21 zero turn mower and it has been running pretty good, but yesterday I went to start it up and it started then died and won’t start back up. It turns over good and the glow plugs are only a year old. I replaced the fuel filters, fuel pump, and fuel hose yesterday but I’m still not getting gas. When I pull the return line off gas is coming all the way through, but when I loosened the injectors no gas was coming out. Could it be the fuel injection pump? Is it possible to just clean it to get it working or does it need to be replaced?
Do you have the manual?
Since you opened the fuel system and now it is not starting it sure sounds like there is a bleeding procedure you did not follow.
Do not start taking things apart as you will turn a simple problem into a major one.
Dave

p.s.
Forum ZD21 troublesshooting.jpg


forum ZD21 Bleeding.jpg
 
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Whatscooking

Active member

Equipment
Grand L 3130. BX2360. RTV900. GRASSHOPPER 721D
May 19, 2021
122
60
28
Indiana
Just went through this with my Grasshopper. Bought it new,721D, in 01. Have taken extra good care of it, i thought. Thought it was losing power over time especially with a bagger on it. Thought i would do some checking by looking at the rubber fuel lines. Tightened up the clamps and took off. Didn't even make it 50 ft. Limped back to the shop. On this Grasshopper the fuel pickup tube unscrews so i pulled it out and tried to blow through it, ha ha plugged tight. Cleaned that out but still not wanting to start right. Went back to the fuel lines. Upon close inspection when bending the rubber lines cracks glore. Replaced every line. Fired right up and barley grunts when mowing hard, glad to have her back.
Check your pickup tube, lines,filter, anywhere it could suck air or be plugged.
 
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Dieseldonato

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B7510 hydro, yanmar ym146, cub cadet 1450, 582,782
Mar 15, 2022
728
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Pa
If it has an electric fuel pump some of them have fine screens in them that can get gunked up as well. And fuel flow needs to be checked before the injection pump, fuel coming out of the return is more or less irrelevant. Fuel supply needs check.
 

Captain13

Active member

Equipment
M7040 4WD ROPS, ZD28, Woods (84” box blade, 72” harrow, 48” pallet forks)
Feb 27, 2019
516
168
43
Kathleen, GA
I’m a little confused. this a ZD21, right? So we are talking diesel, not gas.
The fuel shutoff solenoid can cause your problem. You could disconnect the cable going to it and see if it will start and run. If it does, you will have to manually operate the lever to the fuel pump to shut it down. i had to replace mine a couple of weeks ago because it failed in the open position and the key wouldn’t shut it off. The solenoid is just forward of the air filter housing. It should have a two wire harness running to it. The rod is connected from The solenoid to a lever on the pump. Takes about 15 minutes to replace if that’s your problem.

Also, there is a micro switch for the blade engage that can get clippings, etc on it that will now allow the engine to run. It’s on the right side controls. Look under the shroud where the blade control handle is. Use a flashlight and you will see the small black micro switch. Make sure there is no debris around the switch’s blade. Do not bent the switch’s blade.

i believe all of your safety switches are tied in to the fuel shutoff solenoid (seat, blade engage, steering handles, parking brake) so they all have to be functional or the engine will not start.
 
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North Idaho Wolfman

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Lifetime Member

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
28,306
4,856
113
Sandpoint, ID
Hey. I’ve got a ZD21 zero turn mower and it has been running pretty good, but yesterday I went to start it up and it started then died and won’t start back up. It turns over good and the glow plugs are only a year old. I replaced the fuel filters, fuel pump, and fuel hose yesterday but I’m still not getting gas. When I pull the return line off gas is coming all the way through, but when I loosened the injectors no gas was coming out. Could it be the fuel injection pump? Is it possible to just clean it to get it working or does it need to be replaced?
When I read GAS this many times when your talking about a DIESEL engine, is it possible you put GAS in your Diesel?
 
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