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View Full Version : 26 HP EFI Kohler trouble


TOOMUCHWALKING
06-11-2007, 01:08 AM
Hi Folks , I'm hoping someone has had this same problem and can tell me which part might be causing...the mower won't restart . The first start of the day , works right . Go to restart it , and no go . It's a 2001 Exmark Lazer Z with 925 hours , 150 PSI in both holes . I have spark , fuel . During the no-start phase , it will crank till the battery goes dead and you can smell fuel . I repalced the oxygen sensor and blasted the plugs today with no change . For the last 2 weeks , you could get it started with the battery booster pack . :cry: :hammerhead: Ideas ?? Thanks

fixer67
06-12-2007, 09:55 PM
Turn the switch to the run position but do not start. Listen for the fuel pump to run. If you do not hear the fuel pump running it is a VERY good chance you have cook the ECU (computer). That will cost you about $400 to replace if so. You CAN NOT jump start Kohler EFI engines. The voltage spike will cook the computer. You most likely got lucky a few times jump starting it but it sounds like you luck ran out. Sorry

TOOMUCHWALKING
06-12-2007, 10:08 PM
Thanks for the reply . The fuel pump cycles just like it always has . Today the mechanic I use replaced the ignition switch , opc relay and blade clutch (unrelated ).It started up nicely , and I ran it at half throttle and cycled the blade clutch about six times , then shut it off . It would not restart . During the no-restart condition , when you crank it over it sounds like it fires the plugs once and then stops firing . One irate phone call later , I was advised it would need a throttle position sensor . What other consumables are in there ? :dizzy: :drinkup: This sucks.....

fixer67
06-13-2007, 12:09 AM
Thanks for the reply . The fuel pump cycles just like it always has . Today the mechanic I use replaced the ignition switch , opc relay and blade clutch (unrelated ).It started up nicely , and I ran it at half throttle and cycled the blade clutch about six times , then shut it off . It would not restart . During the no-restart condition , when you crank it over it sounds like it fires the plugs once and then stops firing . One irate phone call later , I was advised it would need a throttle position sensor . What other consumables are in there ? :dizzy: :drinkup: This sucks.....

You really do not want to know. Like I said EFI engines do not like to be jump started. When you disconnect the good battery you are using as a jumper the voltage regulator looses it reference voltage and the output spikes. The output can jump to over 30 volts. This last just a split second but long enough to fry the computer and related items. Even if you did not fry the computer it sounds like it may have got a little brain damage from the jump starting. After the tech replaces and resets the TPS there is no guaranteeing that the Crankshaft position sensor (CPS) or the O2 sensor or one if not both injectors or one if not both coils are not damaged. I work on Walkers that use the Kohler 26 EFI engine and I have seen all kinds of damage done just because they were jump started. You may do it a few times and get away with it it in the end it will bit you. I have seen damage range from $400 to over $600 in damage. I think the record was like $800 when the CPU and TPS and CPS and one injector and the wiring harness was damaged. Please if any one out there have any engine that is EFI or computer controlled be it mower or car or truck engine be forewarned there do not like being jumped started. I have seen air bags in cars set off from jump starting. Sorry for all the bad news. I hope it is not as bad as I have stated it could be. I wish you a lot of luck.



PS=Throw away the jumper cables.

TOOMUCHWALKING
06-13-2007, 12:49 AM
It's a battery pack , and I always let the mower recharge the pack . So while we're on doom and gloom , what else should be checked ? Is the factory diagnostic kit worthwhile ?

fixer67
06-13-2007, 01:26 AM
It's a battery pack , and I always let the mower recharge the pack . So while we're on doom and gloom , what else should be checked ? Is the factory diagnostic kit worthwhile ?

The factory kidiagnostic kit you speak of runs on a computer (desktop or laptop) and the program and cable cost about $300 last I remember. I would say have the TSP replaced and reset and just hope it is OK. If not you will know soon enough. Maybe I am a little on the doom and gloom side and I am sorry for that but each summer I seen at least 3 and as high as 6 EFIs fried from jump starting. But if you can still here the fuel pump running then you may be OK. The fuel pump is the first thing the ECU switches on and if that does not switch you then you have problems. You maybe OK after the TSP is replaced and reset. I just wanted you have a heads up for what could happen. There is no use worrying about it now. Just wait and see what happens and then take it from there. If there shop you took it to is a Kohler Dealer then they should have the EFI diagnostic kit. I know we do. We run it on an old laptop the boss use to use before the upgraded.

TOOMUCHWALKING
06-18-2007, 08:06 AM
O.K. ! It's fixed now , I think . Technician replaced the TPS and did a factory " wiring upgrade " which involved a ground to the computer and a different oil pressure sensor !?!?!? Wish me luck...

Meadowbrook
07-17-2007, 07:22 PM
While we're at it....where are the codes listed for those 26 hp efi Kohler's? I'm throwing a code on each of my eXmark's. Not a big deal, they both run fine, but never the less, they're having an issue somewhere. Everyone else, if you have an eXmark with an efi motor (26hp) turn the key on & off 3 times, let it on the third time & if your lil' light blinks in different sequences, you have a problem somewhere. If anybody knows where to find out what numbers are what, let me know. One of my buddies works at an eXmark dealer, but I really don't wanna bug him.

Chris

thecrankshaft
07-18-2007, 10:49 AM
O.K. ! It's fixed now , I think . Technician replaced the TPS and did a factory " wiring upgrade " which involved a ground to the computer and a different oil pressure sensor !?!?!? Wish me luck...

Kohler has a kit to upgrade the ground from the EFI computer (ECU) and the kit also includes a new oil temp sensor that has a weather-pak connector to prevent corrosion.

Codes can be found in the service manuals for the engines - go to www.kohlerplus, enter as a guest, then go to service literature. They will also throw a code 61 to signal end transmission.