2000 Ski with 2005 Excalibur engine Stalls

[audiodude]

Hi I have a 2000 Ski Nautique with a 2005 Excalibur engine and zero off. The boat runs fine, but, when attempting to pull a skier it will start to accelerate and then stop as if I pulled the throttle back, the engine continues to idle I pull the throttle back and then accelerate and it will pull just fine. If I put the boat slowly in reverse for a couple of seconds it will then pull fine. Sometimes when I put the boat in gear and attempt to slowly accelerate I put the throttle down but the boat only continues to idle until I pull back on the throttle and then it will act normally and accelerate. Anyone have any ideas as to what is going on with this boat. I checked for cracks around the cap and module as someone suggested but don't see any. Thanks!

[NautiqueJeff]

Sounds like either a ZO issue or possibly a potentiometer issue with the throttle control.

[jpwhit]

You can't put Zero Off on a 2005 Excalibur engine unless the engine ECU has been changed to an eControls ECU. Which is no small feat to accomplish. Are you sure you don't have a Perfect Pass speed control? If so, does it have the mechanical throttle cable servo that winds up cord such that perfect pass can release tension on the throttle cable? If you have that servo, then you could have an issue with the servo or a problem with the linkage, or the throttle return spring.

It's possible that you could have a Drive By Wire (DBW) perfect pass system. That was only available a for a few years right before Zero Off was introduced in 2008. But I can't remember if it goes all the way back to 2005. Because that was only available for a few years, you're not going to find that much knowledge out there about that system. If that's the system you're dealing with, I'd call Perfect Pass technical support.

[audiodude]

Hi thanks for the replies. Here is a picture of the tag on the engine. When I bought the boat I was told it was a 2005 engine. It says Excalibur 330 on the engine cover. It is definitely a Zero Off system.

[jpwhit]

Can you post a picture of the Zero Off and a picture of the top of the engine with the cover removed.

[SilentSeven]

I think jpwhit is leading you down the correct path.

To be Zero Off compatible (without any modifications), the factory engine would be the Excalibur 343...not the 330.

Clear pictures of the top of your engine with the cover off and the speed control dash gauge will help a lot.

[audiodude]

Hi again thanks for the replies, I am away from the boat for the next couple of weeks. I will post pictures when I get back.
Art

[audiodude]

Hi I am finally back. Here are some photos of the Zero Off and engine. Let me know what you all think.
Thanks,
Art

[jpwhit]

Looks like someone did do a pretty extensive update to that engine. They've added an e-controls ECM, likely have changed out the engine wiring harness, throttle body, and some of the sensors.

Either that, or the engine is newer than 2005. It could be a very late in the year 2007 EX330 what came equipped with an eControls ECM. My ski club had a late in the year 196 with that engine and Zero Off. But those engine's typically have a red top cover. I've never seen one with a gray cover. Which is why maybe it is a 2005 that's had a bunch of modifications.

In any case, this engine is actually closer to a PCM EX343 now than the EX330 in terms the electronics and the engine control system. One of the first questions that comes to mind, if this engine has been heavily modified, were the modifications done correctly. How long have you had this boat? Has it ever worked correctly? What do you know about the history and engine replacement?

Assuming it's been modified correctly or is a late model 2007 engine, then the following may be the source of your problem.

In the third picture, I see the throttle cable hooked to the Throttle Control Position Sensor (TCP) in the top right corner of the picture. Take a really close look at the TCP and see if the plastic case and/or mounting tabs are cracked. The plastic housing has a tendency to start falling apart with age. It could be broken loose from its mounting plate. Which could explain why putting it in reverse has an effect on the problem. If this is the case, then the TCP may be functioning correctly electrically, but you're getting strange behavior because it's physically moving around. In which case, you may be able to fix the issue, for at least some amount of time, by glueing everything back together. I would use some really strong epoxy type glue, such as gray Marine-Tex, after cleaning all the surfaces with alcohol. If the case is falling apart, be very careful taking it off the boat and putting glue on to hold it together. If it comes apart, the internals typically don't survive. Even in the best case, this will likely only be a temporary fix until you can replace the TCP.

If the sensor is damaged electrically, which can by caused by the cracked case letting contaminates in, falling apart to where the internal potentiometer pieces fall out of place, or due to a straight electrical failure, you're going to have to replace the TCP. Unfortunately, the original TCP used on engines of this age is no longer available. Nautique sells an alternate part, but to use the alternate part you'll have to have the ECU re-programmed. See the details in the listing for the newer alternate TCP here.

https://nautiqueparts.com/potentiome...-sensor-2007-/

Also in the third picture, I see the CANBUS diagnostic connector, with its dust cover attached, right near the oil filler cap. You, or a shop, can connect Rhinda Diacom to the connector and if it's the TCP is failing electrically, you'll have codes stored in the ECM. You'll need to use the Diacom adapter and software setting for the EX343 for this to work. If you follow the instructions for the EX330, it's going to assume the engine has an MEFI ECM and it'll direct you to use the wrong adapter and software setting. Also, in Diacom, you can watch the live graph of what the ECM thinks is the %throttle as you move the lever around based on the reading it's getting from the TCP.

[audiodude]

Thank you for the info. I will take a closer look at the TCP. I bought the boat last year. I was told that the upgrade was done by a ski instructor, last name Byrd.
I haven't been able to contact the guy I bought it from. When I test drove the boat I don't recall any issues so I'm not sure if it was that way from when I bought it. I will try to reach out to the guy I got it from again for more info.

[jpwhit]

I had another thought, and this is somewhat based on the red pen writing on the E-Controls ECM in your 2nd picture. I think that's where someone noted the firmware configuration loaded on that ECM. Which makes me feel pretty certain this is an EX330 that has been updated to be the same as the 2nd half of the 2007 model year of the EX330 where PCM started introducing the E-Controls ECM. I really think they should have given that brief transition model between the typical EX330 and EX343 a different model number. They should have called that short-lived series something like the "EX330+". Just to prevent this kind of confusion.

The reason someone updating a EX330 to be Zero Off compatible would convert to this short-lived intermediate version, is they wouldn't have had to replace the throttle body. That version still used the same throttle body as the EX330. The EX343 went to a larger throttle body to increase the HP. Another reason I suspect this is the case is if the throttle body had been switched out it would look a cleaner/newer than what I see in the pictures.

I don't know this for a fact, but I would think what I'll refer to as an "EX330+" in the rest of this post, probably had its own unique ECM firmware configuration to account for the smaller throttle body.

Here's another possibility for why your engine may not be working right. When the conversion of this engine was done, they would have had to add the TCP. And it's possible the original TCP was already unavailable, and they had to use the revised TCP. When you look at your TCP, compare it to the pictures of the original version and the revised version in the pictures on the Nautique Parts page. If the TCP on your engine is the revised version, then I think there's a good chance the configuration loaded on your ECM is for the original TCP, and that's why the ECM and the TCP aren't getting along. This would especially be the case if the TCP is in good condition without cracks and is the revised version.

If that's the case, then this might be where you get a little stuck. If this engine has been converted to an "EX330+", PCM may not have developed an ECM firmware configuration for that engine that works with the revised TCP due to the limited quantity of that intermediate engine model. I think if you get to the point where it looks like this may be the case, I think you need to call PCM and discuss what options you may have to get this engine working properly. I suspect the answer may be swap the throttle body out to the newer EX343 throttle body and reload the ECM with firmware for the EX343 with the revised TCP. The upside of this besides getting it working properly, is you'll get the power boast of the EX343. The reason I would discuss it with PCM is because they may have the right ECM configuration for an "EX330+" with the new TCP, or if you have to upgrade the throttle body, they will know if there is anything else that needs to be changed.

[audiodude]

Thanks again JP I did look at the TCP and it looks to be in good shape with no cracks. I will compare it to the pictures and see what I have. I really appreciate you taking the time to help with this!!

[audiodude]

Here some photos of the TCP and throttle body Looks like I have the old style TCP. The only thing I notice is that there is a little bit of play at the screw marked in yellow. Not side to side or up and down but in and out if that makes any sense.

[jpwhit]

I'm pretty certain that's an EX330 throttle body. Here's what the EX343 throttle body looks like.

https://nautiqueparts.com/valve-dbw-...7-4-bolt-mntg/

At this point, I think it's likely the TCP is having issues electrically. I've replaced multiple TCPs that have failed internally due to the potentiometers wearing out. And I've also replaced one that were physically falling apart with cracks in the case.

But because the ECU re-program is required to install the revised TCP, I think it would be wise getting the boat hooked up to Diacom for validation that this is the issue before spending money on parts. I see from your profile that you're in NC. You may want to take the boat to White Lake Marine. They can hook it up to Diacom and tell quickly if their are codes indicated the TCP has been sending bad signals to make sure this is the problem. And because they are also NautiqueParts.com, they will have the TCP in stock if that's needed and they can re-program the ECU.

[audiodude]

JP thanks again. I will give them a call.