VX110 Fault code 29 - Please help

[JTI]

Hi everyone,

I posted on here a little while ago that i was having a problem with a VX110.

The background of the ski is that i just rebuilt the engine due to water damage. Originally after it was rebuild it would not idle and would surge when i could get it to idle. It would turn the spark plugs black very quickly and would stall. Every now and again it would throw up fault 29. Everyone pointed to cam timing, which wasnt out, it turns out the company that i had recondition the cylinder head did not do the valve shimming correctly and the head wasnt holding pressure.

Since then, i have had another company do the valve shimming, and now im still getting fault 29. The ski starts first try, it seems to be idling ok, not surging and revs clean in the garage, all of which were not right previously. I do not even have to start the ski to get the fault to come up, i just tap the start button to ignite the dash and it comes up every time.
Im ripping my hair out trying to find the problem.

I have swapped the Intake pressure sensor with another, i have tested the wires from the Intake pressure sensor to the computer, all of which are fine. I have checked my timing marks 3 times, they are spot on. Could it still possibly be an issue with the head?

What else could it be? Im ready to give up!

[JIM'S PERFORMANCE]

intake air sensor, Make sure it's not unplugged or corroded.

[JTI]

intake air sensor, Make sure it's not unplugged or corroded.

I know that it is the intake air pressure/temp sensor (map sensor). It is pluged in, it is not corroded, i have swapped it with another sensor with no luck, i have tested the wires that go from the sensor to the ECU which are all fine. It throws the code whether i have the ski started or just ignite the dash.

[JIM'S PERFORMANCE]

intake air sensor, Make sure it's not unplugged or corroded.

I know that it is the intake air pressure/temp sensor (map sensor). It is pluged in, it is not corroded, i have swapped it with another sensor with no luck, i have tested the wires that go from the sensor to the ECU which are all fine. It throws the code whether i have the ski started or just ignite the dash.

If you do not even have to start it to get the code you have a dead short, Three things it can be sensor, wiring or ecu that is it it's not mechanical.

[JTI]

intake air sensor, Make sure it's not unplugged or corroded.

I know that it is the intake air pressure/temp sensor (map sensor). It is pluged in, it is not corroded, i have swapped it with another sensor with no luck, i have tested the wires that go from the sensor to the ECU which are all fine. It throws the code whether i have the ski started or just ignite the dash.

If you do not even have to start it to get the code you have a dead short, Three things it can be sensor, wiring or ecu that is it it's not mechanical.

What do you mean when you say "that is if it is not mechanical"? What mechanically could be causing this problem?

[JIM'S PERFORMANCE]

intake air sensor, Make sure it's not unplugged or corroded.

I know that it is the intake air pressure/temp sensor (map sensor). It is pluged in, it is not corroded, i have swapped it with another sensor with no luck, i have tested the wires that go from the sensor to the ECU which are all fine. It throws the code whether i have the ski started or just ignite the dash.

If you do not even have to start it to get the code you have a dead short, Three things it can be sensor, wiring or ecu that is it it's not mechanical.

What do you mean when you say "that is if it is not mechanical"? What mechanically could be causing this problem?

If the valves are adjusted to tight or the timing chain jumped you will not have good vacuum and it can trip that code because the sensor is picking up that the vacuum is not correct, But in your case you do not need to start it to get that code so it's electrical.

[JTI]

intake air sensor, Make sure it's not unplugged or corroded.

I know that it is the intake air pressure/temp sensor (map sensor). It is pluged in, it is not corroded, i have swapped it with another sensor with no luck, i have tested the wires that go from the sensor to the ECU which are all fine. It throws the code whether i have the ski started or just ignite the dash.

If you do not even have to start it to get the code you have a dead short, Three things it can be sensor, wiring or ecu that is it it's not mechanical.

What do you mean when you say "that is if it is not mechanical"? What mechanically could be causing this problem?

If the valves are adjusted to tight or the timing chain jumped you will not have good vacuum and it can trip that code because the sensor is picking up that the vacuum is not correct, But in your case you do not need to start it to get that code so it's electrical.

Thank you for explaining. Much appreciated.

[JIM'S PERFORMANCE]

intake air sensor, Make sure it's not unplugged or corroded.

I know that it is the intake air pressure/temp sensor (map sensor). It is pluged in, it is not corroded, i have swapped it with another sensor with no luck, i have tested the wires that go from the sensor to the ECU which are all fine. It throws the code whether i have the ski started or just ignite the dash.

If you do not even have to start it to get the code you have a dead short, Three things it can be sensor, wiring or ecu that is it it's not mechanical.

What do you mean when you say "that is if it is not mechanical"? What mechanically could be causing this problem?

If the valves are adjusted to tight or the timing chain jumped you will not have good vacuum and it can trip that code because the sensor is picking up that the vacuum is not correct, But in your case you do not need to start it to get that code so it's electrical.

Thank you for explaining. Much appreciated.

You are very welcome.

[JTI]

So today i borrowed a CDI computer of a mate that has the same ski, i have installed it and the problem is still there. Whether i start the ski or no the check engine light comes on and it is fault 29. Today i again swapped over the Intake manifold temp/pressure sensor (MAP sensor) with still no luck and have re-tested the wiring which all tests fine.

The CDI was my last hope. Anyone with any ideas...?

[JTI]

UPDATE:

So i took the ski to the local Yamaha dealer today to have it plugged into the YDS to read the faults and to try and see if they could figure it out also.

On the YDS, the fault comes up and without it started the intake air pressure is 126.08 kPa. Then with it started the fault is still there and the YDS set to engine monitor, the intake air pressure is 125.9 kPa. According to the dealer, this is all running correctly, besides having a fault code.

They were as stumped with it as i was, so i took it home with no outcome.

Can anyone confirm if these kPa reading are correct for a VX110? Like is said, the dealer said they were, but why is the sensor going off?

They also replaced the intake air pressure/temp sensor (map sensor) with a new one just to try, which didnt work.

[JoeyDFZS]

Thats not right 126.8kpa is 18.39psi..........I doubt your N/A motor is running that kinda manafold pressure at idle or off or running wide open for that matter

[JTI]

Thats not right 126.8kpa is 18.39psi..........I doubt your N/A motor is running that kinda manafold pressure at idle or off or running wide open for that matter

Oh really? Ok, i would not know, i am only going off what they said. You think that this is way too high?

[JTI]

Can anyone with access to a YDS and a VX110 please do me a massive favor and check your intake manifold air pressure and post it up for me.

[JoeyDFZS]

Sounds like the Map sensor is bad........ there is a test for it in the Manual no?

[JTI]

There is not test that i could find, but i have swapped it out with 2 different MAP sensors. One used, then one new. Both of which did not fix the problem. And like i state earlier in my posts, i have also swapped out the CDI computer with no affect at all.