Any ideas: '97 SN GT 40

[Drago]

She starts but only runs for about 2-3 second before the 15 amp circuit breaker (next to ECM back of engine, there are 3: a 60(?), a 15, and a 12.5).

I picked up my boat after it spent a month in Hanksville getting the trailer repaired, filled it up and headed for the lake. Very disappointed kids, but at least we have a house to go home to, unlike some in Colorado. Blown out anyway:)

[TWB]

My fuel pump (I think the low pressure, but can't remember) was seized and cause a fuse to burn.

[cragginshred]

Go to correct craft fan.com site if you have not already. By far the best resource on the web for your Nautique.

 

http://www.correctcraftfan.com/forum/default.asp

[Drago]

Awesome, thanks @cragginshred and @TWB , I'm still at Lake Powell, will -do after I drag her home

[lb]

It usually doesn't blow the fuse that quick but if your connection at the safety switch is bad or the switch is bad it will present the same way you can put a jumper wire in to test. I agree that it is probably a fuel pump issue. that is what the lanyard switch turns off.

[Drago]

Thanks@lb, I did jump the safety switch, should have said that originally. I think I'll check those wires back as far as I can just to be sure.

[A_B]

Check the grounds on the back of he engine block while you are chasing wires.

The PCM trouble shooting guide is really good to go through on these issues.

Google it or find on Planet Nautique.

[Drago]

Will do, thanks @AB

[Drago]

I swapped the two relays back there, since they were the same, nothing different.

[Wish]

This thread is a good read and at the end. It WILL solve you problem.

http://www.ballofspray.com/forum#/discussion/4367/sn-gt-40-won-t-stay-running-help

[A_B]

I will tell you that I thought I was onto something with the fuses for my intermittent problem. Turns out that when I was messing around with the fuses, I was jostling the ECM mount and later found that tapping lightly on the ECM caused the pumps to run fine then crap out. I hope it is just a bad LP pump.

 

I jumped my pump on the back tester box, so ruled my pump out. I forget which slot, but easy to do. Need a stripped wire with an alligator clip on it. Plug the wire into the right slot and clip the other end on metal. Also ran the volume test to see why rail pressure was all over. Pump tested fine. Hated pumping gas into a jar, but really only way to see what the pump was doing by itself. Test calls for x seconds and x ounces. Spelled out in trouble shooting guide.

[A_B]

http://www.correctcraftfan.com/Downloads/Pro_BOss_GT-40_Service_Manual.pdf

 

 

[Drago]

Good reading @ab and @wish. Not being near the boat now, I have a great game plan and feel good about finding the problem. Just in time to winterize;(

[Drago]

Actually, I wouldn't want to chase the EOS wiring around since that would not cause the breaker to pop(?)

[Doug]

Its your low pressure pump I have had 2 customers boats do the same thing change out the Carter pump you will be $$ Call Vince at SKIDIMS he will send one out the same day

[A_B]

They are easy enough to throw on. I replaced mine, and it ended up not being the problem any way. Sold my old good pump on here to some lucky Baller who actually needed one.

[A_B]

@Drago, just in case you are bored after putting the boat up, here is my problem with my '99 GT40, discussed ad nauseum with some of the experts on CorrectCraftFan.com: (there are a couple guys out there who really know their stuff!)

 

http://www.correctcraftfan.com/forum/forum_posts.asp?TID=25775&PN=1&title=99-sn-gt40-fuel-supply

[Drago]

Wow @ab, I got through p3, I want to skip to the ending.... Or u can just tell me the conclusion. Hop mine doesn't take that long. :(

[Drago]

Thanks @doug

[jhughes]

Bad low pressure fuel pump, for sure.

[Drago]

@doug, I don't see a lp pump at skidims, carter is the lp pump for 97 GT40? What's that set me back , approx?

[A_B]

Pump is about $125 if I remember. My ECM was bad and telling the fuel pump to do crazy things. $500+ and a major pain to figure out. There is no error codes for it. Everyone says they rule everything else out. The funny thing was that a few months sooner I had two friends who had GT40's that I could have swapped an ECM out to try, but both had sold them and bought 09 SN's when the problem hit. That would have saved a bunch of time. The weird part was that I accidentally found that tapping on the ECM would make the pumps work then cut out again a few seconds later. I knew all about the relays from one going bad a couple years earlier. Replaced the fuses because tapping on them made it work,but in reality, the ECM was being jiggled when I tapped on the fuses. Chased every darn wire on the boat! Took fuel tank out etc.... I had a fuel pump gauge, so I could see the pressure going crazy. One would think it was the pump, until I jumped it and saw it was working fine.

[JC McCavit]

@AB - Who did you get the new ECM from, and how much did it cost. Was it the 300 model?

[A_B]

Jody hooked me up. It was over $500 if I remember correctly. I figured I owned the boat for 12 years, so not bad. Just a few other odds and ends. Hated to sell it, but ZO on a 2007 co-owning with my lake partner seemed to make the most sense.

[Drago]

Yeah, @ab, your link reads like a novel. I can picture you in there pulling your hair out.,

[A_B]

Ate a lot of donuts...

[A_B]

@JC McCavit, yes, 300M version. That is the upgraded version that took care of the surging issue of the first generation GT40's.

[Drago]

Didn't see it in the manual, any spec on how much pressure the low pressure pump puts out? I disconnected the line btwn LP and HP pump and she's spewing out gas pretty well....

[A_B]

Pressure on the schraeder valve should be up around 30-40 psi if I remember. The link to my discussion i posted has a link to a video of how my pressure would start out normal and then fluctuate wildly between zero and normal.

[Drago]

Yes, 32-40, something like that. That's after the HP pump , though. I don't find an LP pressure in the manual, guess it doesn't matter because there is no way to measure it there anyway.there is pressure exiting the LP pump , I would hate to replace if that's not It. Neither is making obvious priming sound. I'll jump them next time. Rain all day, changing to snow. Thanks @AB, not a single donut yet!

[DanE]

@Drago If neither pump is not priming when you turn the key on (they should prime about 2 seconds) you could have a bad diode in the cable harness feeding the fuel pump relay.

Had that problem myself (don´t have a wiring diagram handy right now), easy fix once I found the location of the diodes.

 

[A_B]

The LP feeds the FCC and the HP feeds the rail. I was told the LP would keep the engine running at low rpm. There is a jump for each pump on the test connector on the back of the motor. Hard to hear the HP inside the FCC, but can be felt by grabbing the FCC with bare hand.

 

If you put new pump relays in, jumped the kill switch, and checked the fuse coming off the battery in the red line, if you have one, mine did not have, and the pumps prime randomly or not, i hate to say it, but sounds like you are headed for an ECM. Any one of your friends have a GT40 that would let you swap their ECM in for a test? That would be quick and rule out the ultimate big $ fix.

[Drago]

Thanks @AB and. @danE, I think I do have a friend w/ a '97. I'll check the other stuff next time out to the boat.

[Drago]

Update: didn't look at the boat all summer because of work and tournament skiing for my son.

after checking the kill switch, fuse at battery, back-flow valve, pumps priming (they did), hp filter, relays, actual circuit breaker... Maybe more things that I've forgotten, I jumped the hp pump directly from the battery: ran great and didn't kill the breaker.Plugged the hp pump back in, and jumped the LP pump from the battery, ran great and didn't pop the breaker either,

BUT-- the wires I was holding onto the LP pump terminals got Really Hot really quickly. So, big hunch something was wrong with the LP pump. Called DIM, 10 minute install (new pump had a pigtail and plug), she's up and running!!!

20-20 hindsight : that was easy ;)

Thanks to all of you for your wisdom, and Vince at dim.