GT-40 not starting

[rmillard]

I am stumped? MY 1999 Air Nautique with EFI, runs great when it starts. Randonly, when turning the ignition key on it either starts fine or the starter cranks without trying to start? Sit there in the water and wait and it starts up 5 to six times, and then will not start again? It is totally random when it starts and does not? I thought maybe a loose ground but not so? Any ideas???

[xlair]

Does the starter crank but the engine doesn't start? Or do you just hear a clicking sound? Could be a bad starter or starter solenoid.

[rmillard]

No, cranks fine. It seams like a sensor or ignition problem that is random?

[Chexi]

Bad gas?

[rmillard]

No, 30 gal of new gas, boat runs perfect when it starts. It just starts or does not start randomly.

[DanielC]

When it is not starting do this:
http://www.planetnautique.com/vb3/sh...light=ignition.
If you have good spark do this:
http://www.planetnautique.com/vb3/sh...=fuel+pressure

[slob02]

Fuse at battery......lanyard issue.......but probably the Relays on back of the motor. Are you hearing the fuel pumps cycle when you turn on the key?

[ricky]

I just went through the same issue with my 2003 Super Air - PCM 330

Read through the thread I posted and take a look at everything I troubleshooted. My issue ended up being a corroded distributor/rotor and I was thrown off because I still saw it sparking at plugs...just was too weak and inconstant to ignite fuel.

http://www.planetnautique.com/vb3/sh...t-not-starting

[rmillard]

yes, I hear the fuel pump click on when first starting. It may be a fuse or electrical problem. I will try these suggestions. Thanks Bob

[Chexi]

Take what I say with a grain of salt. I am by no means an engine expert. However, definitely look into the relays on the back of the engine and see if others with that issue had similar symptoms (I believe they have). That seems to be a common problem and an easy and inexpensive fix.

[DanielC]

Once again, did you check for spark, and did you check the fuel pressure?
Just because you hear a relay click, or a fuel pump run does not mean anything.
There are two fuel pumps. Both must work, if one is bad, the engine will not run.

[jedgell]

I had the same issue last year. I replaced my positive battery cable and it's been fine since. I think over time the wires had worked themselves loose from the connector.

[newfoundskier]

Did you have any luck getting this resolved? I am having the exact same issue with a 97 Ski Nautique with the GT-40.

[DanielC]

GT-40 not starting

The engine cranks, but does not start, here is what to do. No cranking is an entirely different problem.

Engines are simple. They need three things to run. Compression, ignition, and fuel. Supply all three in the proper amount, at the proper time, and the engine will run. Millions of internal combustion engines prove that every day.

If nothing catastrophic happened to your engine, ("It was running just fine, and then I heard a loud bang, and smoke filled the engine compartment") the compression is probably OK. If you are working on restoring that 1989 2001 Ski Nautique you found on Craig's list, check the compression first. If your compression is low, you are probably looking at spending a major amount of money, and it does not matter if the ignition and fuel are perfect, the engine has to have decent compression to run.

With good or even excellent compression, without spark your engine will not run. If it has spark, and the spark is at the wrong time, the engine also may not run, but I can promise you that without any spark, your engine will not run.

You have to have fuel. in fact, the lanyard that shuts off the GT-40 engine does it by stopping the fuel supply. On a GT-40 engine, shutting off the fuel suddenly, kills the engine as quick as shutting off the ignition.
The computer in a GT-40 engine does not monitor the fuel air ratio. It does not know if any fuel is getting to the fuel injectors, nor how much is actually getting into the engines cylinders.
The computer assumes the fuel pressure is correct, and knows how long to open the fuel injectors, for the conditions the engine is running under, but it has no feedback the amount of fuel actually going into the engine. That is why you have to check the fuel pressure on a poorly running GT-40, or one that is not starting.

That is why at the beginning of this thread, I ask to check the spark, and the fuel pressure. Doing that really helps all the people out here who know your GT-40 engine help you.
Or you could randomly replace parts, until you get lucky. After all, marine engine parts are not really that expensive.

[eseybold]

i had the same problem last yearas - it was the 9 dollar relays in the back of engine.