I started a thread about two months ago over here.
Cliff notes:
Husqvarna ZTH 7226 I've since tried everything I can think of and still have the same problem. Engine starts up fine, and usally when it gets close to temp, it starts hunting and then stalls and dies. On two occasions, it's run like a champ with no issues, once running for nearly 4 hours mowing, towing, and doing laps around my buddy's trailer park.
Picked up the mower in February for what I thought was a good price. It had the same issue of starting to slowly hunt when heating up and getting progresivley worse to the point where the rpm would drop to where it would stall. The issue seemed to be fuel related to me (throttle changes would make it bog like a carb with too big an accelerator shot), and looking at the fuel system patch work, I thought it would be an easy fix. Cleaned the tanks, installed new lines and filters. Fired right up but quickly found the issue persisted. I checked all my connections, installed new fittings where i thought they may be even questionable and installed a known good fuel pump. Ran good for about 45min with varying throttle, rpm, load and pto on/off. I deemed it good and went back to make everything nice and neat....Went back out the next day to finish mowing and the same f#$@ing thing!!!
Checked the computer, and found TPS code. WIthout doing ay further troubleshooting ordered a TPS and installed....Same issue. Tested TPS resistance through its range at sensor and at ECU. Went through the TPS learning procedure, but could never get the MIL to confirm things recalibrated...I gave up and brought it to my old ladys friends husbands place (he works at a mower shop). We chased down each ECU wire to its end and checked for connectivity. Fixed a questionable ground and it ran for 4 hours....Everything seemed great, the sun was shinning, life was good I FINALLY had a good mower...Untill we went to put it on the trailer...same thing!!! Pulled the oil temp sensor thinking that keeping it from going open loop would make it run...nope
He did some more testing of rail pressure, sensors, etc....As a last ditch effort he sonic cleaned the injectors and rail....to no avail.
I dont have the money to take it to a shop and have a scanner bolted on this thing. I've been scouring craigslist for an engine that will pull this thing to no avail. Neither of us can figure it out...has good compression, spark and is getting fuel (although i cant verify injector duty cycle when at temp). Please...help
James
Cliff notes:
Husqvarna ZTH 7226 I've since tried everything I can think of and still have the same problem. Engine starts up fine, and usally when it gets close to temp, it starts hunting and then stalls and dies. On two occasions, it's run like a champ with no issues, once running for nearly 4 hours mowing, towing, and doing laps around my buddy's trailer park.
Picked up the mower in February for what I thought was a good price. It had the same issue of starting to slowly hunt when heating up and getting progresivley worse to the point where the rpm would drop to where it would stall. The issue seemed to be fuel related to me (throttle changes would make it bog like a carb with too big an accelerator shot), and looking at the fuel system patch work, I thought it would be an easy fix. Cleaned the tanks, installed new lines and filters. Fired right up but quickly found the issue persisted. I checked all my connections, installed new fittings where i thought they may be even questionable and installed a known good fuel pump. Ran good for about 45min with varying throttle, rpm, load and pto on/off. I deemed it good and went back to make everything nice and neat....Went back out the next day to finish mowing and the same f#$@ing thing!!!
Checked the computer, and found TPS code. WIthout doing ay further troubleshooting ordered a TPS and installed....Same issue. Tested TPS resistance through its range at sensor and at ECU. Went through the TPS learning procedure, but could never get the MIL to confirm things recalibrated...I gave up and brought it to my old ladys friends husbands place (he works at a mower shop). We chased down each ECU wire to its end and checked for connectivity. Fixed a questionable ground and it ran for 4 hours....Everything seemed great, the sun was shinning, life was good I FINALLY had a good mower...Untill we went to put it on the trailer...same thing!!! Pulled the oil temp sensor thinking that keeping it from going open loop would make it run...nope
He did some more testing of rail pressure, sensors, etc....As a last ditch effort he sonic cleaned the injectors and rail....to no avail.
I dont have the money to take it to a shop and have a scanner bolted on this thing. I've been scouring craigslist for an engine that will pull this thing to no avail. Neither of us can figure it out...has good compression, spark and is getting fuel (although i cant verify injector duty cycle when at temp). Please...help
James