03' Wakesetter VLX Indmar Monsoon 335

[dj468]

I've read through a hundred hours of forum questions over the past 2 summers. Lots of problems sound similar but I've replaced all the items that solved their issues to no avail.

I have owned the boat for 11 years and never had an issue until 3 years ago when we had a couple trans bolts break that were repaired. Then beginning of summer last year the engine problems began. Many new parts and 2 dealers/mechanics later and no resolution (one is a Mastercraft dealer and the other is a former Malibu dealer). Both have lots of experience with this/similar motor.

Boat idles rough (started when issues started) but runs great after throttling up for 2-3 minutes until it reaches temperature (160). After about a minute it falters then loses power. RPM's surge, boat continues to move but with almost no power that continues to fade. Move to neutral and it resets. Boat runs great for about 20 seconds and all repeats. I can do the neutral reset a 100 times and it never changes. The dealers have not been able to duplicate the fail while in the shop.

It went to the MC dealer 1st because he is closest to my house: they said the ECM was bad and needed to be repaired. Sent it out for repair. Boat came back and ran for about 4 hours and then failed. After 6 weeks of them not giving my boat attention I took the boat back. Then it went to the Malibu dealer that has serviced/winterized it for me the past 11 years.

This is what the former Malibu dealer detailed for me; We found a bad ground last year (19') in the motor and fixed. Motor ran well after that for a couple of hours and then failed and wouldn't start/run. Then we changed the complete distributor because we had no spark. Boat would start and run but then the original power failure returned.
Then we changed the distributor again because the motor had no spark again and we found the module in the distributor bad so we changed.
The last time in we found the distributor module bad again and changed. Also checked all the power wires and grounds and found one of the grounds going into the ECM to be bad. Repaired but are questioning, since day 1, the ECM rebuild that the other dealer had done. When we hook either my Rinda hand held or Laptop I often can’t get a connection to ECM.
Motor also doesn’t run well at idle compared to other like motors. We are at a loss.
Here is what has been done, checked, replaced.

• ECU was sent out for a rebuild
• Fuel filter replaced
• Fuel pump replaced
• Fuel pressure regulator replaced
• Fuel injectors professionally cleaned and tested  
• Fuel pressure is solid at 44 psi even when boat is failing.
• MAF replaced
• TPS replaced
• New gasket on air intake
• New distributor
•  Plugs
• Wires

Any thoughts on this would be helpful.

[RedWakesetterVLX]

Man that’s tough.  If your gut is telling you the ECU rebuilt was no good I’d go back to that or just buy a new one. I know they are not cheap.  Anyway to have it tested?

[formulaben]

6 hours ago, dj468 said:

Then we changed the distributor again because the motor had no spark again and we found the module in the distributor bad so we changed.
The last time in we found the distributor module bad again and changed.

Did they use the thermal paste on the module?  Did they look at (clean or replace) the IAC?  Also, at this point I'd replace the coil since they are relatively cheap.

[dj468]

The IAC was replaced. Forgot that in my list. Coil has not been, so will try that. If that does not work I will probably pull the ECM and send it out for testing.  

[justgary]

Is the throttle body clean inside? 

Can you rig up a gas tank to run the engine?  Your fuel lines could be rotting and have random clogging issues. 

Does your rinda unit allow you to grab data while the engine is running?  Comparing good to bad can tell you a lot. 

[dj468]

The ECM is not read by the Rinda most of the time. Both handheld and laptop. Believe it's the ECM. When it does connect it shows no issues, which of course is not true. That being said we've never had the boat fail in the shop. Fuel pressure is excellent all the time including when the boat is failing. 

Edited August 1, 2020 by dj468
Mispell

[justgary]

You or your repair place found poor connections, then found more poor connections.  Go through the power circuit of the engine and make sure every connection is clean and tight.  Note that this doesn't mean make sure they *look* good.  Remove each connection, clean it, and put it back.  From the battery to the engine, both positive and return connections.  Pay special attention to the cannon plug at the engine and the ground lugs on the engine.  For the cannon plug, use a small blade and *gently* spread the male contacts before you replace the plug.

Does your Rinda only read codes, or can it read live data?

[dj468]

Update:

After talking with my car mechanic we decided to do a compression test. 

Cylinders 

1 - 180psi   2 - 150

3 - 160        4 - 150

5 - 15          6 - 90

7 - 160        8 - 150

Obviously I have an issue. Mechanic is doing a leak down test on Saturday.  Hoping it's just the head gaskets.......

My question; what are the head, exhaust manifold and valve cover gaskets I need to order?

[dj468]

Update: After finding the low compression numbers top half of the motor was rebuilt, bent valves, bottom half looked in excellent shape. Boat still not running. It was at Skipper Bud's in Madison, WI (Malibu dealer) all last summer and they were not able to find the issue. MEFI 4 ECM and distributor burned again and they through up their hands. I'm done messing with the current electronics. Talking with the engine builder and the techs at Holley this is what they are recommending. 

https://www.holley.com/products/fuel_systems/fuel_injection/terminator_x/terminator_x_and_x_max_universal_kits/terminator_x_universal_kits/parts/550-936

https://www.holley.com/products/ignition/distributors/chevrolet/dual_sync_distributors/parts/565-200

Has anyone out there done anything like this to their boat? Any input would be greatly appreciated. 

[Dbrake]

How did it turn out?