2000 exmark laser missing.

[gnccer150]

It has a 26 fuel injected kohler and it will miss sometimes with the deck engaged and @ full throttle. If you disengage the deck it will run fine or if you back the throttle down just a tad it will not miss anymore. It seemed as though the e-brake switch was the culprit but bypassed the switch and same problem occured. any help is appreciated.

[Brianslawn]

is the O2 sensor clean?

[gnccer150]

Don't know.. Can I just unbolt clean and put back in the manifold.
thanks in advance

[1grnlwn]

Check air filter.

[Jman]

How many hours are on the unit? When was the last time plugs and fuel filter changed?

[gnccer150]

1100 hours. Air filter and plugs were both replaced before the mowing season. Unit had the miss all year, but would come and go.

[Jman]

Change the fuel filter and the oxygen sensor.

[gnccer150]

Just did the fuel filter. I will order a 02 sensor and replace. It is cold here so it will be a few months before I can check it out.

[Oldtimer]

The engine has a diagnostic plug. Take it to your dealer and he will be able to find the problem in a few minutes.

Oldtimer

[Jman]

make sure the dealer has the EFI diagnostic program. Not all dealers have those.

[viper00085]

there are many updates out on these efii's also to help that problem. First make sure you have no exhaust leaks anywhere, check o2 sensor and wiring, then start looking at the ground update kit, temp sensor update kit, making sure all the pin connectors on the efi ecu connector are clean and rust/debris free. also the last update out there to look into (its expensive) is the new TPS and intake manifold kit. the older tps axial shafts would wear out and not make good contact with electrical scrub connectors in it and cause a lean or rich mixture issues, and even if you dont do this repair, you should take it to a dealer to hook up the puter and do a re-learn on the tps set -up for the ecu's sake. Good Luck, Vinny