2016 F70 Issues

[99yam40]

I checked the voltage in the harness unplugged from the sensor and its jumping from 2V-5V watching it, verifying what the computer shows. I have a video of it not sure how to post it.

I would find out what all gets that 5 volt feed and disconnect them one at a time to see it the voltage stops jumping around.
I am fairly sure not all are fed from same source

[Double_A]

id you check the 5 volt reference voltage to the TPS and intake pressure?
if that is bouncing around it would cause all kind of problems

Possibly one of the sensors going bad causing the voltage to get out of spec ,
or in and out

I checked the voltage in the harness unplugged from the sensor and its jumping from 2V-5V watching it, verifying what the computer shows. I have a video of it not sure how to post it.

[99yam40]

I have been experiencing the same problem with a 2011 F70 300hrs. I When the problem fist appeared the boat was running fine then total loss of power and surging. When it cooled down it would run normally. The problem was inconsistent it would happen, then it would be another 10 hrs before it would happen again. I took the boat to my trusted mechanic and he couldn't find any thing wrong. Originally I thought it was a fuel problem and tried a remote tank, no change. I have replaced everything from the fuel pickup in the tank to the VST pump. The problem has been getting worse, it shows now in 8 minutes of running. I purchased the computer diagnostic system from ebay. I had the motor running (cold) ran fine for 8 minutes, then it just shutoff. On the computer I noticed the TPS and Intake Pressure fluctuating wildly with the motor not running. I opened the throttle and the intake pressure changed but still moved wildly. I checked the harness voltage to the TPS and it's showing what the computer shows. My guess its the ECM, I have a call into the mechanic to get his input. Hpoefully he will call me today.

id you check the 5 volt reference voltage to the TPS and intake pressure?
if that is bouncing around it would cause all kind of problems

Possibly one of the sensors going bad causing the voltage to get out of spec ,
or in and out

[panasonic]

One more comment. I would look very carefully at the plug for the HP pump for pin and socket fitment issues. Same at the ECU plug. A bad pin or socket, loose or corroded, can cause problems like you are experiencing.

[Gatorlizard]

I have been experiencing the same problem with a 2011 F70 300hrs. I When the problem fist appeared the boat was running fine then total loss of power and surging. When it cooled down it would run normally. The problem was inconsistent it would happen, then it would be another 10 hrs before it would happen again. I took the boat to my trusted mechanic and he couldn't find any thing wrong. Originally I thought it was a fuel problem and tried a remote tank, no change. I have replaced everything from the fuel pickup in the tank to the VST pump. The problem has been getting worse, it shows now in 8 minutes of running. I purchased the computer diagnostic system from ebay. I had the motor running (cold) ran fine for 8 minutes, then it just shutoff. On the computer I noticed the TPS and Intake Pressure fluctuating wildly with the motor not running. I opened the throttle and the intake pressure changed but still moved wildly. I checked the harness voltage to the TPS and it's showing what the computer shows. My guess its the ECM, I have a call into the mechanic to get his input. Hpoefully he will call me today.

Sounds like we are walking down the same path. The mechanic that has my boat called me last night and says he now suspects the ECM. He finally got around to checking the fuel pump ground. "yam" had mentioned in an earlier post checking if the fuel pump ground was dropped by the ECM causing the shutdown. Luck for me he has access to a proven used ECM he can try before buying a new one.

[Double_A]

I have been experiencing the same problem with a 2011 F70 300hrs. I When the problem fist appeared the boat was running fine then total loss of power and surging. When it cooled down it would run normally. The problem was inconsistent it would happen, then it would be another 10 hrs before it would happen again. I took the boat to my trusted mechanic and he couldn't find any thing wrong. Originally I thought it was a fuel problem and tried a remote tank, no change. I have replaced everything from the fuel pickup in the tank to the VST pump. The problem has been getting worse, it shows now in 8 minutes of running. I purchased the computer diagnostic system from ebay. I had the motor running (cold) ran fine for 8 minutes, then it just shutoff. On the computer I noticed the TPS and Intake Pressure fluctuating wildly with the motor not running. I opened the throttle and the intake pressure changed but still moved wildly. I checked the harness voltage to the TPS and it's showing what the computer shows. My guess its the ECM, I have a call into the mechanic to get his input. Hpoefully he will call me today.

[Gatorlizard]

what electrical are you thinking is the problem?
monitor it to see if that is the problem

I have no idea. If I did I wouldn't be here asking stupid questions. Let me ask another one.. When all this started 5 months ago with the motor cold I could cycle the ignition switch and hear the HP pump make a whining/buzzing sound for a couple of seconds. Last week after being in the shop for 3 months It ran for 35 minutes and shut off. When cycling the switch it made a faint squealing sound. Not the sound I remember hearing before. The guy that had it for 3 months said he ran it till it shut down and said there was power to the HP pump but no fuel pressure on the rail. He replaced the pump. Obviously it didn't fix the problem.

[99yam40]

I can only assume it is because the ambient temp under the cowling is causing something electrical to temporally fail. Think about this scenario.... My lawn mower runs for 5 minutes and shuts down. 5 minutes later it starts up and runs for another 5 minutes. Easy diagnosis.. It's the coil. I wish my issue was this easy to solve.

.

what electrical are you thinking is the problem?
monitor it to see if that is the problem

[Gatorlizard]

all I can say is prove it is not a problem before eliminating it as the problem.
you eliminate enough things it will lead you somewhere.

why would this problem only be there when the cowling in on?

I can only assume it is because the ambient temp under the cowling is causing something electrical to temporally fail. Think about this scenario.... My lawn mower runs for 5 minutes and shuts down. 5 minutes later it starts up and runs for another 5 minutes. Easy diagnosis.. It's the coil. I wish my issue was this easy to solve.

.

[99yam40]

all I can say is prove it is not a problem before eliminating it as the problem.
you eliminate enough things it will lead you somewhere.

why would this problem only be there when the cowling in on?

[Gatorlizard]

I'm still here. I've ask before.... How can the VST be run dry when after cooling off the motor starts instantly with just a bump of the key?? Not naw, naw naw and it starts. Click vroom and it's running.

[pstephens46]

Where did he go?

[99yam40]

heat buildup maybe?
could the fuel cooler not be working properly, and the pump fails from overheat?
or maybe the VST gets hot enough to boil off the fuel in it so runs dry and fails the pump??

[panasonic]

so it does not happen with the cowling off?
that seems like an important clue

I am wondering the same thing

[99yam40]

In the driveway with the cowling on.

so it does not happen with the cowling off?
that seems like an important clue