Heat Soak problem

[Rock_Toy]

Those symptoms definitely point to a rare condition referred to as "over-bling" :mrgreen: The boat actually forces you to stop so that it can show itself off. There's no cure for it. Might as well crack a cold one and turn up the tunes Yellow_Flash_Colorz:

[DanielC]

If I am understanding you correctly, the fuel pressure stays up, and the boat dies, indicating an ignition problem. Is that correct?
Have you downloaded the GT-40 service manual, yet?
It has a very good troubleshooting section.

[Grant_West]

Dan you are correct.

I have tryed to find the loose wire by running the boat for a while and then trying to wiggle the wires at the back of the motor by the computer to see if i can make the fuel pump turn on and off. I havent had any luck. the only time I can get the fuel pump to turn on and of by wiggleing the wires is when the motor die's

[DanielC]

Have you downloaded the GT-40 service manual, yet?
It has a very good troubleshooting section.

[DanielC]

The computer tells the fuel pumps to run at these times. When the wire at the test port is grounded, when the motor is running, and sending a signal from the crank position sensor, when the starter is engaged, and when the key is first turned on.
I know it is hard to isolate an intermittent problem when it is not present, but try to keep track of every thing you do, and all the things that happen.
If you cannot figure this out, the more info you give the service center you use, the easier it will be for them.

[Grant_West]

Im guessing its only a matter of time before I find the wire or loose connection.
Ill keep track of what wires do nothing when I pull on them so I can narrow it down.

It was super hard to track down the bad connection or what was ever making the pump turn on and off. All the wire's were all zit tie'd to each other so pulling on one was like pulling on them all. Ill keep track like you said and see what pop's up. Ill be at the lake this weekend to try it out

[DanielC]

When the motor dies, and you wiggle the wires, that causes the fuel pumps to run for a few seconds, is that correct?
This behavior would cause me to think the problem with the power being supplied to the engines computer. The computer turns the fuel pumps on for about two seconds when the key is switched on, and then the computer switches them off, if the engine is not cranked, or started.
Switched power, when the key is on, gets to the engine on a purple wire. There is a 10 pin connector on the back of the motor that this wire goes through. Just for fun, I would take this connector apart, see if it has any oxidation or corrosion on the pins that make contact. Clean them shiny and bright, and put it back together.

[Grant_West]

Dan I know the 10 Pin connector your talking about. It a Rubber square style plug.
When I plug and un plug that connection YES the fuel pump fire's just like you switched the key on and off. This connection seem'd to be some what pulled apart. I pushed it together and thought "NO WAY" this cant be my problem or the fix. Sure enough the boat die'd later that day. Ill bring up some electrical contact cleaner and take a closer look into that connection. The wires that seemed to make the fuel pumps run were lockated down by the start relay. But like I said I could not pin point the wire or connection that was giving me the problem. There was to many wires that would move at once when you pulled on a single wire. This weekend is supposed to be hot so the boat should do its tricks quite often and I will get more chances to try to pin point the bad connection.
Again thanks again for all your help up to this point.

[DanielC]

Grant, I have been thinking about this problem. I do not mean to nag, but have you downloaded the GT-40 service manual, yet?
Lets identify a few things so when we write back and forth we are talking about the same thing.
There is a round device on the backside of the steel plate, that holds the computer, and other electrical devices on the back of the motor. It looks like a Ford starter solenoid, or relay. It is not for the starter, it is called the "assist solenoid" When this part goes bad, typically you cannot crank the engine. I believe this "assist soleniod" switches power to the key, or control box if you have a touchpad system.
There are two relays on the plate that holds the engine electronics. One is the ECC system relay, the other is the fuel pump relay. These are more or less standard Bosch type relays.
The ECC (Engine Control Computer?) relay closes when the key is switched on, or the touch pad on your boat is switched on. The coil of this relay is grounded, and is activated when power is applied to it. When this relay is closed, power is applied to the ignition system, the ECC, and the coil of the fuel pump relay.
The fuel pump relay coil is not grounded normally, it is grounded by the ECC, when the ECC thinks it is appropriate.
I am leaning to thinking you have a problem with the power to the ECC relay, the ECC relay, or the ground for the ECC relay. This relay being intermittant will cause the ECC to think the key, or your equivalant was just switched on, and causes your fuel pumps to run for about two seconds.
If any of this does not make sense to you, reply back to me, and I will try to explain it a different way.

[Grant_West]

Dan I know exactley what your talking about. The 2 Bosh style relays are brand new. I just replaced them with factory PCM relay's.

The starter assist solonoid your talking about is NEW as well. I just replaced it with a factory solonoid. ( I broke it on accident trying to tighten one of the nuts)

What your saying about the relay grounds being bad makes alot of sence. The first time I went to wiggle wires I wiggled the relays and they seemed to be the problem. I was moving them back and forth and the fuel pump was going on and off as I moved the relay's. Later when the motor did it thing again moving the relays had no effect???
I started looking else where. Where do the ECC realys ground. I bet thats the problem

[DanielC]

One of the Bosch style relays is for the ECC, the ignition, and it supplies power to the coil of the fuel pump relay. This relay's coil has a normal ground, and the coils power is switched by the key.
The fuel pump relay's coil is grounded by the ECC, and gets its power from the contacts on the ECC system relay.

[Grant_West]

Im not complaining but my boat didnt do it's usuall this weeknd. I wasnt able to get it to die. It ran fine all weekend

[STANGKILLASS]

fuel pump drawing too many amps?
could trip a relay or temp fuse, or even some internal program in the ecu

[Grant_West]

I found the problem. It was a fusable link comming of the start solonoid. There was 2 wire's in the loom next to each other. The one that was bad had a purple wire comming off of it. The connection at one end was no good. I traced it down to a section of the loom where I come bend the wire's and make the pump turn on and off. I cut a section of the loom open and exposed the bad wire's. Like I said it was 2 wire's side by side. They were both fusable links. The one thats attached to the start solonoid was bad. I cut it open and I could see that where the purple wire crimp's to the fusable link was bad. Im sure it made a bad connection and when the motor got hot the connection opend and killed the motor. I took some pick's of the bad wire so you could see what Im talking about. Ill up load them. Thanks for all the help everyone gave me tracking down this problem.