GT40 stops after letting go of button

I have gone through in as much detail as I can the Poor Mans GT40 section without the proper tools… I do not have a lanyard as it is bypassed and I even checked the connection of the wires as it was this way when I bought it. I checked the 20amp fuse at the battery and tried the jumper to the STO Connector and it does not seem to be turning on the full pump. I can make the engine run as long as I want by keeping my finger on the start button and it is only after I left go that it shuts off.

There seems to be some kind of panel way under the dash next to my bilge pump override switch but I am not sure what it is for.

I tried a new relay from Advanced auto and it did nothing different. I when around the engine looking for loose connections but nothing made a difference.

I plan on making some jumper wires of various lengths and to bring my multi-tester with me next weekend. I don't have any of those tools at the lake. I do not have a Star Tester to follow the diagnostic steps in the GT40 Manual..


It is a Boss 5.8 in a 2001' year Ski Nautique
Any help would be appreciated.

That's easy, Don't stop pushing the start button!

Would suspect the keypad like GearE mentioned but would also wonder if a low voltage issue? Have you gone through the electrical connections and cleaned as req'd??

If the lanyard or it's bypass was a problem I don't think it would run at all.

So you press and hold start and continue holding after it starts, does the starter remain engaged??

When you code up the keypad initially the green light should go on after your code and a single push of start, when you press start again that should be ignition, gauges should activate, you should hear fuel pumps prime, then pressing and holding start again should activate the starter.

Is this what you are seeing/hearing??

Get a voltmeter already.

Sorry, it seemed like this thread was older than it really is.

Fuel system. Battery -> pumps
Ignition system. Battery -> plugs

In a nutshell, compare running to non-running. You shouldn't have to recreate the wheel for running, I would think the manuals available should hint at probable component failure.

I don't have a cover over the plug wires... I will have to get one, those have to be generic. I will put on the list, thanks!

Thanks jhersy29, will do... What is an mtb tube?

Gotcha, will try tube first and put distributor cover on the list.

Ordered it... free shipping:)

All though I am not too confident that it will fix this problem it will sure avoid another. I would think if continuing to push the starter button and the engine actually settling down into idle and even the PerfectPass beeping saying it is ready my guess is I am going to find the problem either in poor connection somewhere actually off the engine.

Whoever worked on the boat last did kind of a messy job around the relays but it is obvious that there was some work done. I know for one thing I am going to get to know this engine and other than messing with my skiing I enjoy working on engines/boats.

So when I am in start mode (the port side led is green on the keypad) vs. actually pushing the start button while in start mode I should have power to the coil?

Hmmm... I replaced my oil pressure switch about a month ago. I can disconnect that and still have the analog and see if it is the problem. Thanks

I had replaced it becuase the old one failed and it would put me into limp mode.

Saturday... I have used the boat at least 5 different times since I replaced the oil pressure switch.

Hey, I appreciate the thought and am going to take the time to disconnect it just becuase.... I thought that switch basically told the computer if it was above 5psi and when it went below that with the boat running it would put it into limp mode. Does it do more than that?

Brian from the described symptoms it may be a problem with the keypad and or PME Gateway box. I do not have the circuit diagram of a GT40 with this configuration. But as they still have the same EEC and fuel pump relay I assume that operation after the keypad and PME box is mostly the same as the standard ignition key GT40.

The keypad is trigger mechanism to the PME Gateway to distribute power. Most of the electronics are inside this box. It distributes the power to the engine and throughout the boat.

Test for voltage at EEC relay you should even be able to feel the relay click in and out with a finger. The 12V output from the EEC relay goes to the coil, TFI ignition module and ECM. It sounds like you are losing the activation power for the EEC relay so check terminal 85 on the relay for 12V. You will need to make up 4 short jumper wires for the relay to make testing easier with voltmeter.