Zero off acceleration issues

[Orlando76]

My buddy's 2007 Ski Nautique with Excalibur and ZO. A few weeks ago we noticed when we drop a skier and bump into reverse most of the time the Check engine light flashes for about 3 seconds. Temp and oil looks good, but the oil pressure may drop to about 24 psi according to gauge. Thought maybe 25 psi is the limit for the system and maybe the sender is getting tired.

 

This weekend when (only I) I'd take off to pull up a skier I'd throttle down and it was like there's nothing there, go to reverse and same thing. Move the controller down and no revs. Just in gear idle. Once skier is in, pop open dog house, swap drivers, etc and problems stops. Every time it's done it we noticed a slight whining noise from possibly rear of engine. Today when it did It i noticed RPM's jumped maybe 50 turns. Suggestions?

 

[gregy]

Could be going into some kind of a limp mode. Take it a shop or find someone with a marine code reader.

 

 

 

[Jody_Seal]

Check all your grounds.

[Orlando76]

Grounds are checked and cleaned. No issues there except definitely nasty corrosion on positive terminal. Hoped it could've been that along with weak battery. All cleaned up, new battery and problem is still. Same symptoms. Can anybody in Central Florida recommend a PCM/zero off mechanic?

[Gloersen]

could be a failing throttle body or bad potentiometer.

contact Skip Dunlap

[Orlando76]

I'm feeling potentiometer or possible adjustment issue, perhaps weak return spring or not fully engaging transmission?

 

Skip Dunlap sounds familiar but I'm drawing a blank. Forum member?

[Gloersen]

ZO is only DBW so no return spring. The potentiometer is the TCP sensor assembly.

 

pm'd you Skip Dunlap email address

[Zman]

Doesn't sound ZO related. Does that boat have a screen where you can check to see which engine diagnostic code is giving you the check engine indicator, like on Malibus? If so, get the SPN and FMI off the screen, and google it, or call Skip as Peter suggested.

[mac]

Same symptoms with ZO off? Or maybe the pedal position sensor in the throttle assembly is going bad? If it is similar to the one MasterCraft uses, apparently you can take it apart and clean the contact portion on the sensor or just buy a new one ($80) vs the whole throttle assembly that MasterCraft suggests for $650...see this thread

 

LONG LINK TO TEAM TALK

[Gloersen]

If it is just the TCP sensor assembly, it may be that just replacing the potentiometer will do.

 

But a Diacom dx eval should be 1st priority.

[eleeski]

I had my throttle go dead once. My water pump was leaking and got the engine wet and steamy. I left it for a while and came back to the throttle not responding. Inspection showed that the butterfly valve at the front of the manifold was stuck closed. A bit of WD40 and a clean up fixed it.

 

Our van would get sticky there and run badly. Again, the quick clean out cured that as well. Try the mechanical fix first.

 

Eric

[Orlando76]

@Gloersen appears to got it right. Finally got to play and look around a ZO Excal for the first time and learned a few things. Right away first thing I saw was a significant crack in potentiometer housing. Not sure if that is the reason for the check engine light coming on but surely it's the throttle issue. Thanks for the pointers.