HELP! - Engies dies

[peteSki]

Having a problem with my 97 Ski, hoping someone else has had this and can tell me what the problem might be.

Boat details: 97 Ski with 5.8L GT-40 fuel injected. Reconditioned 80 hours ago.

Problem: This has happened 3 times so far. Once at slalom speed, once at wakeboard speed and once just in idle. While purring along, the engine completely dies without any warning. No sputtering like it's not getting fuel or miss firing on a cylinder.. just dies. When I try to restart, the engine cranks over no problem, but never does it ever begin to run. After about 4-5 minutes of sitting there, she cranks up like there was never a problem and continues to run. Yesterday it did this twice in the span of about 10 minutes, then ran fine for the rest of the day. No power loss, sputtering or anything. Visual inspection of the engine looks good as there didn't seem to be anything obvious.

Any help greatly appreciated.

Pete

[DanielC]

RE: HELP! - Engies dies

Peteski, I also have a 1997 ski,GT-40. I have 1594.5 hours on mine. At 920 hours, mine died, and did not run, but it sounded like it wanted to start, sometimes. I had a bad fuel pump. Get the fuel pressure checked, at the injection rail, there is a schrader fitting for this. On marine fuel injection engines there is no feedback into the computer on how rich or lean the engine is running, so if the fuel injection pressure is off, the computer does not compensate for it.

[slob02]

RE: HELP! - Engies dies

I just cut and pasted what I posted a few days ago here again!

I can't believe how many people are having trouble with the same thing on here.
I have heard to check:
1. The fuse coming from the battery
2. The kill switch safety laynard.
3. The fuel pump
4. The relays.

My problem was the the relay on the left had a bad connection and wasn't giving power to the relay on the right which gives the fuel pump power. If I would wiggle it, it would give the right one power and the pump would kick on.
Sometimes it would run fine for days and others it may stall a few times an hour.

[peteSki]

Thanks slob02, I actually found your post after doing a search. Thanks for reposting here. Thinking back, I seem to recall not hearing the fuel pump engage when turning the key just after the engine quit. The next time it happens I will check for this.

I can see a relay problem being intermittent, but if it's a problem with the fuel pump itself, my thinking is that it will either work or fail entirely.

I'm going to replace the relay this weekend as a starting point and see how it goes.

Pete

[slob02]

I agree with you. A fuel pump SHOULD be an all or none. I would almost bet is in the relays or their connections. Keep us posted.

[peteSki]

Well I replaced both relays today and examined all the connections. They all looked fine. Boat ran as usual for the first hour, then died just as before so the relays were obviously not the problem. This time we were ready for the failure, we had an extra spark plug in the boat so we tested for spark just after the engine died and there was no spark. I also noticed that when the key was turned to the run position, the fuel pump would not make its usual sound before starting. Could hear the relays clicking but nothing from the pump. Again after about 4 minutes, turning the key to run we could hear the fuel pump and the engine then started up and ran fine for the rest of the day with no failures.

Maybe the ignition coil is bad? Do they usually fail in this sort of manner? Maybe it's temperature related?

Any thoughts are welcome...

Pete

[slob02]

I doubt it would make a difference.......but my connections looked clean and clear, but it took some needle-nose pylers and tightened them up a bit. When the boat would stall I could squeeze the relay on the right together tighter and that would cause the pump to kick in. Remember the pump will only stay on so long and you have to turn the key off and back on. It think it cycles for something like 15sec.??? Just another thought! Good luck.

[peteSki]

Update.....

After getting hold of the GT-40 service manual and talking with numerous marine and auto electrical 'experts', here's the scenario:

Most agree that the intermittent nature of this problem and the fact that there is no spark during a failure point to a problem with the ignition module. I also measured the resistance of the primary coil on the ignition coil and found it to be higher than the specified tolerance.

I've ordered a new ignition coil and module and am currently awaiting delivery.

Meanwhile it's 100F and sunny out (Australian summer) so I'm bumming rides behind any Nautique I can find 8-)

Pete

[bkhallpass]

Pete. Had a very similar problem with my 2001. Took it to the dealer. They replaced
some kind of computer module, and went away.

BKH

[peteSki]

Just replaced the ignition module and coil and went for a water test. The problem was still the same.

I went back and read some of the other posts here regarding similar problems and was drawn back to check the battery connections and the inline fuse from the smaller wire off the + terminal that feeds the EEC relay. The terminals themselves were fine as I had inspected them before, but I didn't bother to actually open up the fuse and have a look.

This time I did, and the fuse casing was cracked and the wire was discoloured from heat exposure underneath the plastic sheilding. The fuse itself looked OK, but the connection inside the holder looked corroded and also didn't look like it contacted the entire end of the fuse. I cleaned up this connection and on the next test run the boat ran perfect. I did notice that this fuse holder started to heat up, probably not as much as it did before I cleaned it as I improved the connection within but not replaced it with a new one.

So couple of questions come to mind:

1) Is it normal for this inline fuse to heat up during use?
2) Does the holder have a spring mechanism inside that keeps contact with the fuse (mine didn't appear to have one or it was seized)
3) Is there anything special about this fuse other than being 50A and time delay?

I plan to replace it locally with a new one, but it won't be from Nautique. I'm assuming I can just substitute any 50A time delay fuse and it should work fine.

Pete

[slob02]

Glad to see you found your problem. Good Job!!! I know some people just cut the fuse out and crip the wires together. I don't know if that is the best solution though. It seems like it do remember a spring loaded feeling at the fuse.