Engine starts then dies. Need help asap.

Ok. I screwd up big last night. It was late, I was tired & I couldn't see real well. That's my lame excuse. I hooked up the positive to negative & vice versa on the battery. It tripped the 60 amp circuit breaker. I reset it and hooked everything up correctly, but when I got to the lake it wouldn't stay running. It will start just fine, but only stays running for about 2 seconds. What do I need to do??????

This is a 1996 SuperSport with the gt-40 engine.

Please help!!! I would like to get on the water tomorrow and don't want to have to pay a million dollars to take my boat to the shop on Tuesday.

Thanks,
Robert

Sounds like a wire, fuse, or fuseable link on the ignition switch or starter.

Another item you will need to check is the alternator. Reverse polarity often blows diodes in the alternator. It may not charge when you get the engine running. Happens real often when someone tries to use booster cables and hooks the battery up reversed.

Clean the IAC. The GT40 motors are notorious for idle issues.

I wasn't clear on the engine dies part. The electrical power shuts off to the engine, guages, etc after about 2 seconds of the engine running. I know this is due to me hooking up the battery wrong, but I thought that the main breaker would protect everything. I reset it and have power to everything until I start the motor.

What is the IAC and do you think this is what is wrong after I explained my situation better?

(Message edited by rkh on July 26, 2008)

IAC is idle air control, doubt if you caused it to go bad by reverse polarity. The 2 seconds you talk about sounds like the time for your key to return to the run position from the start position.
When in the start position power goes through the starter solonid to the ignition (distributor/electronic spark control) when in run position it comes from another terminal on the ignition switch. I had the "run" wire come off of the ignition switch once and it exhibited the same symptoms.

Starter solonids have 2 small wires, one comes from the key switch, and the other goes to the distributor. It is labeled "I" on the solonid. That wire is often a fuseable link on older cars and boats. I'm not sure on yours, but with the symptoms you describe that is one place I would look. In addition to checking the ignition switch.

I checked again today and I was mistaken about power being cutoff to the guages etc. The engine runs for 2 seconds and then just dies. The guages still have power.

I'm not very good working on things, obviously, so I don't know where to look for the solenoid. I have the owner's manual, but the diagram doesn't show the solenoid. It does show a wiring diagram with a fuseable link to the 12.5amp breaker, but my boat doesn't seem to have that same setup.

I've checked every other wire I could find, but can't find a fuse that's popped. Could I have fried the 12.5 or 15 amp breakers instead of just tripping them?

I'll check the back of the ignition switch for any loose connections.

(Message edited by rkh on July 27, 2008)

the motor will have to go through a re- learn procedure. during this time it could idle ruff or stall. this happens when you remove power from the ecm.once you get it moving with some throttle drive it around for at least 20-30 minutes the more you drive it the better it will get. vary the speeds it should come back around for you.

My bad, didn't notice the reverse polarity part for some reason.

It starts just fine, but it will not run for more than 1 or 2 seconds. It doesn't slowly die. When it shuts off, it cuts off immediately.

It's almost like the fuel is just cutoff. Is there 2 systems delivering fuel? One for start up & one for running?

This is really getting frustrating! I guess I'm just stuck taking it to the shop & spending more money. I was just hoping someone could point me to the fuse that needed to be replaced. Oh well.

Thanks for the help though.

Sounds like an ignition relay- I did the same thing a few years ago and went through everythin before I tried the relay and bingo- it's about a 20 dollar part- I don't know where they are on your motor- but shouldbe on top near the throttle body.

I'll try the ignition relay. I'll check the owners manual, but I don't remember seeing it in the diagram. What should it look like? If I can find it, do I just need to do an ohm test to see if the circuit is still complete?

This may sound really stupid but if your boat came equipped with a "safety lanyard" (probably part of the throttle/gear shift) check and make sure it is properly installed.

My son removed mine one time and I spent half the day debugging that problem. Symptom was pretty close to what you described, it would start and run as long I held the key to start but would die as soon as I released the starter.

Rod

^^^^^
Yep, I'm with Rod...bypass the lanyard by connecting the two wire together and see if it solves the problem.

I think George hit it "fuseable link on the ignition switch or starter"

My boat was doing the same thing. When it would get hot it would die. It would re-star and then die like 1-2 seconds later. It turned out to be a fuseable link. Its a wire thats located in the Main harness. You will need to go and cut your harness apart to find it. Cut out or replace the fuseable link and you should be all good

BTW I have the same PCM GT40

Here is a picture of the fusable link that went bad in my boat. Its a purple wire comming off the start relay.
I think it gives power to the fuel pump. It would make contact when the motor was cold and then when it would get hot the fusable link would get hot and then break contact. It would cause the boat to run for a few seconds and then shut down JUST LIKE WHEN THE LANYARD IS DISCONECTED. If I described the problem to people this was their first answer.
I made my lanyard a solid connection so I wont have the problem of it comming off and killing the boat

Well, the lanyard people win this round. I had absolutely no problems like this before my stupid human error. I think that's why I didn't even think to check the lanyard. A wire connection had come off.

Thanks for all the help,

Robert