Kohler 28EFI problems

[cward76]

Just bought a new Z last week 3/9/06. It has the 28hp Kohler EFI on it. After 1.8 of playing around on it the motor all of a sudden started running like it was flooding. I put it up and called my dealer. He came out and took a look at it. When we starter it up it sounded twice as bad as the day before. It was only running on one cylinder. Changed around the coils and plugs and found that the back cylinder had a low compression. He thinks that the fuel injection system maybe the problem. He hoped nothing was wrong internal with the engine.
Has anyone heard of this happening? Thanks for any info.

[cward76]

Anyone Out There

[work_it]

If you're already having problems with the mower after 1.8 hours you may want to consider having your dealer trade it out for another mower. If you're having problems with the engine now there's a good chance you'll continue having problems the entire time you own it.

Keep in mind that there's not a manufacturer out there that doesn't eventually produce a lemmon.

[Richard Martin]

I've had no problems with mine. Did your dealer run the ECU self diagnostic? I don't quite understand how he can blame the EFI for low compression.

[cward76]

If you're already having problems with the mower after 1.8 hours you may want to consider having your dealer trade it out for another mower. If you're having problems with the engine now there's a good chance you'll continue having problems the entire time you own it.

Keep in mind that there's not a manufacturer out there that doesn't eventually produce a lemmon.

My thoughts exactly. Dealer came by last night and picked it up to take it back to the shop. He said that trading it out might be an option if there is no easy fix. Seems if there is a lemon it will always fall in my hands.

[cward76]

I've had no problems with mine. Did your dealer run the ECU self diagnostic? I don't quite understand how he can blame the EFI for low compression.
This is a question I have been meaning to ask someone about. I don't know whether or not he did, but I did check the code and it displayed a 61. From what I understand this mean that no problem was detected. I do not understand how the engine could be running so poorly with the ECU not picking up anything.

[Envy Lawn Service]

Well, I for one don't believe compression has anything to do with this.
Well not compression as we are considering it...

What I mean is that the dealer probably meant something else.
I think that unless he literally did a compression test on that cylinder right there.

Sounds to me like one cylinder just isn't firing for whatever reason.

Hope your dealer is good with the EFI's though.
Many of them struggled to fix the carb ones, much less EFI.

[Richard Martin]

This is a question I have been meaning to ask someone about. I don't know whether or not he did, but I did check the code and it displayed a 61. From what I understand this mean that no problem was detected. I do not understand how the engine could be running so poorly with the ECU not picking up anything.

A 61 does indicate no codes in the Key On Engine Off mode or the Keep Alive Memory. A quick way to test the ignition portion of the EFI while the engine is running is to look at the tach. If it's nice and smooth then that cylinder generally is having no problems. You would then switch the tach wire to the other plug wire and look for the same thing. If both wires have erratic readings then the EFI definately has a problem. If only one cylinder is having an ignition problem you then switch the coils and see if the problem moves to the other cylinder. If it does then it's the coil, if it doesn't it's the EFI.

If the engine was running rough as soon as you started it then you can also rule out the HEGO (o2) sensor. The EFI only looks at the HEGO sensor after the engine has warmed up.

You can also check to see if the MIL light was flashing codes when the engine is running.

Grounds are extremely important in an EFI system. It sounds like one has not been connected properly or has come loose.

[thecrankshaft]

What is the serial number of this engine?

[puppypaws]

Please let us know what the problem was in detail on your 28 efi.

[cward76]

I will let all of you know what the problem is when I find out for sure.

I talked to my dealer on the phone Friday for just a moment. He said the motor had a hard part problem and there is a new engine on the way.

Thanks for the info.on the EFI. Cheyenne

[cward76]

Well, I guest it was a hard part problem. A hard part called a nut. The service guy told my dealer that Kohler would not let him order a new engine without trying to fix mine first. A nut that did not belong to the engine was found holding one of the valves open. I guess it was dropped in at the factory while they were putting it together.So, he ordered a new head and valves. I did not like the idea of this, so my dealer called me back today and said that he was ordering me a NEW MOWER in and he would take care of getting the other one fixed. It should be here Monday.

[John Gamba]

Well, I guest it was a hard part problem. A hard part called a nut. The service guy told my dealer that Kohler would not let him order a new engine without trying to fix mine first. A nut that did not belong to the engine was found holding one of the valves open. I guess it was dropped in at the factory while they were putting it together.So, he ordered a new head and valves. I did not like the idea of this, so my dealer called me back today and said that he was ordering me a NEW MOWER in and he would take care of getting the other one fixed. It should be here Monday.


Great Dealer:clapping:

[thecrankshaft]

Wow, a nut holding a valve open? Right. If nothing else the lifter would pump up enough to open the valve far enough to drop that nut into the CC.

[lucforce]

A nut of any size holding a valve open would have let the pushrod lose contact with the rocker arm and bent something as the lifter pushed the push rod on the next cycle. Then it could have backfired and blown the head gasket.

[Richard Martin]

A nut of any size holding a valve open would have let the pushrod lose contact with the rocker arm and bent something as the lifter pushed the push rod on the next cycle. Then it could have backfired and blown the head gasket.

The pushrod probably just fell out and then the cam pushed the lifter out. No biggy as long as the nut was still stuck under the valve. Replacing the head would have fixed it but since the dealer is replacing the whole mower then good for you.

Like John said, kudos to the dealer!

[cward76]

A nut of any size holding a valve open would have let the pushrod lose contact with the rocker arm and bent something as the lifter pushed the push rod on the next cycle. Then it could have backfired and blown the head gasket.
It did backfire one time very loud.

[cward76]

New mower arived yesterday like I was told it would. My dealer brought it to my house which is 45 miles away. He has been a great deal of help through this or-deal.I would buy again. Thanks for all the input and help on the matter.