Nice work! Anytime you have a surging issue, always hook up an inline fuel pressure gauge, drive the boat and watch the gauge when the surging happens. You would see low fuel pressure, then you could hook up a meter to the fuel pump and see its voltage is cutting out while its surging. The ECM probably gives the fuel pump relay a ground to activate it which makes sense the ECM was damaged
I have been having a surge and slow firing problem with my GT 40. Just ordered a new computer as I am not as handy with a soldering iron as you are. I am definitely going to pull the old one apart and look at it once the new one arrives. Great video thank you
Good video and good work. I wish I would’ve seen this video and give me some effort to fix mine before I bought the used one. I had the same issues for a few years as you guys.
Great job! The previous owner on my '97 said that it kept dying when they were in Tahoe, but no place else. They said it was one of the relays so they kept a couple on board. I've had the boat for two years now and haven't had a problem (nor on my '96 that I put 1600hrs on from new). But good to know that it's fairly easy to get to the PCB. My '96 I kept in a garage since new so the engine looked pristine even at 1600hrs. The previous owner kept it outside and covered, but it appears they never opened the engine compartment to reduce humidity, because every bit of aluminum is severely oxidized. I'm hoping all of the connectors (especially the one to the ECM) are good; I'm afraid to pull it off in case it falls apart.... Just subscribed. Appreciate the video. Love learning from someone with a bubble but SN with a GT40!
Awesome video, just watched the “tips on driving an inboard” and learned a lot! Also- my family has a cabin about 200m towards the lake from that ending clip (PML)
Thanks for another option in my arsenal. I have a GT-40 in my 1998 Air Nautique and occasionally it won't fire on petrol (I'm in the UK) but it'll run fine on LPG as it's dual fuel. Even knowing that the spark and ECU are fine it's still been difficult to trace the intermittent start/not start issue on petrol. Recently picked up a Carter P4389 and it's been fine since replacement, but I'm still not convinced that was the root cause. The relays I got as part of the diagnosis, direct from Nautique Parts, are 4RD 007 794-31 that might be easier to get hold of than the original part numbers. Hopefully that might help others that happen across this video
That was a great video. You went all the way down the rabbit hole to find and fix the issue. WOW, good job!! 😃
Thank you. It was not easy but I finally got there.
Good job knowing how to diagnose the problem and electrical work. That exhaust sounds good in the water too
Thank you, I still cant believe it. This V8 sounds so great in the water
@@92813justin it does sound good. My moomba has straight dual exhaust but in the water it’s extremely quiet at idle. Almost can’t even hear it
Nice work! Anytime you have a surging issue, always hook up an inline fuel pressure gauge, drive the boat and watch the gauge when the surging happens. You would see low fuel pressure, then you could hook up a meter to the fuel pump and see its voltage is cutting out while its surging. The ECM probably gives the fuel pump relay a ground to activate it which makes sense the ECM was damaged
It was so hard to find this but I am glad it is all fixed.
I have been having a surge and slow firing problem with my GT 40. Just ordered a new computer as I am not as handy with a soldering iron as you are. I am definitely going to pull the old one apart and look at it once the new one arrives. Great video thank you
I hope that fixes your problems
Good video and good work. I wish I would’ve seen this video and give me some effort to fix mine before I bought the used one. I had the same issues for a few years as you guys.
Thanks 👍
Nice job finding the issue. By the way it is not a capacitor but a crystal. Used to generate specific frequencies.
Thanks for posting. That looks like the crystal that provides a 15 MHz clock cycle to the CPU, not a capacitor.
Great job! The previous owner on my '97 said that it kept dying when they were in Tahoe, but no place else. They said it was one of the relays so they kept a couple on board. I've had the boat for two years now and haven't had a problem (nor on my '96 that I put 1600hrs on from new). But good to know that it's fairly easy to get to the PCB. My '96 I kept in a garage since new so the engine looked pristine even at 1600hrs. The previous owner kept it outside and covered, but it appears they never opened the engine compartment to reduce humidity, because every bit of aluminum is severely oxidized. I'm hoping all of the connectors (especially the one to the ECM) are good; I'm afraid to pull it off in case it falls apart....
Just subscribed. Appreciate the video. Love learning from someone with a bubble but SN with a GT40!
Wow, 1,600 hours and still running hard. I’m glad to here it! See you on the water!
Awesome video, just watched the “tips on driving an inboard” and learned a lot! Also- my family has a cabin about 200m towards the lake from that ending clip (PML)
We will be on the lake this summer. Say hi!
Improbable breakdown, good job!
Thanks!
Great job Dude keep up the good work with these informative videos
Thank you
Thanks for another option in my arsenal. I have a GT-40 in my 1998 Air Nautique and occasionally it won't fire on petrol (I'm in the UK) but it'll run fine on LPG as it's dual fuel. Even knowing that the spark and ECU are fine it's still been difficult to trace the intermittent start/not start issue on petrol. Recently picked up a Carter P4389 and it's been fine since replacement, but I'm still not convinced that was the root cause. The relays I got as part of the diagnosis, direct from Nautique Parts, are 4RD 007 794-31 that might be easier to get hold of than the original part numbers. Hopefully that might help others that happen across this video
Great insight
Just bought the same boat but in masters green. 1997 Nautique
Well done. Re-upload with fixing EFI controller in title
Good idea, I am actually going to make a part 2 video because the board failed again
Wow, great find! Also, did you remove your exhaust down-pipe? It sounds “normal”.
Yes I did!
Great video. Thanks for sharing.
Great job
Well done.
thank you
Do you still live near Sacramento ?
No, I am in Texas
Bring back the boat vids
Working on it! Any videos you want me to make?
hibi had sent you a comment in own the same boat can you meet me one day I show you my boat thanks
That sounds great!