GT-40 stalls at start then will immediately restart - anyone seen this?

[SilentSeven]

Searched all the archives etc and did not run into this problem. Anyone with specific experience?

1997 GT40 with 1300 hours

Description: Typically when hot, go to start the boat and it promptly starts and then dies. No sputter, more like ...vrooom...off. Go to restart - same thing. No excessive cranking or anything like that. If you advance throttle to about 2k RPMs or so and then start, it will generally start and run. Once running, will idle fine, run fine.

Annoyingly, the problem seems intermittent and most likely to occur after being run for a period. Seems like the problem is getting worse...boat started this a couple weeks ago and is now seemingly more frequent.

Boat is new to me this season. I've done some basic tuneup work including new wires, new plugs, cleaned up the rotor and cap.

Haven't yet had chance to check FP at the rail, on the list of diagnostics. Heat related seems to suggest engine electronics.

Anyone seen this or have a good short list of items to start with?

Thanks in advance!

[wskiboy]

low pressure fuel pump

[SilentSeven]

That was on my suspect list. Are you speaking from experience with the same issue or is this an educated guess?

[Connor]

Subscribed! My boat (99 SAN, GT40) started doing the same thing a few months ago. I researched a lot, changed the fuel filter, plugs, wires, rotor, etc, tested the low pressure pump, etc. The only way I can get it to start cold is with giving it a little throttle while cranking. Once it is cranked and runs for a few mins it will cut off and on no problem. I have been trying to limp it along until winter before I can really tear into it.

[DanielC]

What are the words I can use to stress the importance of checking the fuel pressure when the problem is occuring?

if fuel pressure is good, my next guess is the IAC, Idle Air Controller.

You can down load the GT-40 service manual from the "downloads" section of Planetnautique.

[SilentSeven]

Hi Conner - is your issue related to hot and cold starting? Mine cold starts fine. It also hot starts fine.

My problem is that once it starts, it immediately shuts off. So, my problem is not really a starting problem - it's more a 'it doesn't continue to run once started' problem.

Do we have the same issue?

[bscott]

The relays for the fuel system and ECM also seem to be temperature sensitive. They are identical relays and are relatively inexpensive to replace.

[SilentSeven]

Yes Dan - As I noted above, I haven't yet checked the FP at the rail. That is on the todo list.

I also have the service manual downloaded and am reviewing it closely.

I have a few emerging ideas on the cause of the problem but was looking for others who have the same issue as this specific failure is not described in the archives. That one else has run into this is interesting and seems hard to believe.

To the actual problem - this is very suspect and is from the Service manual - 'if the ignition switch is not turned to the start position, the ECA will not receive a PIP signal and will shut off the fuel pumps after approximately two seconds'.

As the boat starts and then stalls, it's clear I have enough fuel (and pressure to start). What I don't have is fuel (and pressure) to run. So, the FP key on cycle is running but what appears to be failing is the signal to tell the pumps to re-start once the engine is running. So, at this point I think it's more likely a problem with the PIP signal than the pumps itself. As I stated above - once running, it's fine. It's the transition from pressure up at key on to continuous pressure at run that appears to be failing.

[SilentSeven]

Installed a remanufactured distributor over the weekend. Was planning to install a new pickup but removing the cam gear was impossible with the tools available and a reman unit was $90 via NAPA. Ran the boat about 3 hours yesterday in mixed use - idle cruising, towing. Did not have a repeat of the start/stall issue. Started and ran each time. Did continue to experience 'cut out while running' issues. eg - running at some throttle load, boat momentarily cuts out and then immediately continues. Can do just one hiccup or a couple. Feels very much like an ignition cutout. Going to look again at the kill switch shunting wiring and main relays.

In general boat ran better with new distributor. Idled better without the slight miss it had before. Internals of the old distributor had some rust on the stator, bolts. No real runout on the shaft. Clearly was the original distributor.

[SilentSeven]

The relays for the fuel system and ECM also seem to be temperature sensitive. They are identical relays and are relatively inexpensive to replace.

Yes - they are next on the list. Agree they are both suspect and cheap to replace.

[SilentSeven]

Pictures of my distributor with the hall effect sender on and removed. This is the orginal unit. Wiring pigtail looked good, lots of surface rust, very little shaft runout if any.

[SilentSeven]

Start/stall problem still has not re-surfaced.

Boat is running much smoother with replaced distributor. Idles better, smoother under throttle. Not that it ran bad before but it did have a slight 'tick' in the idle.

[SilentSeven]

Cross post to a similar problem solved by a distributor swap out.

LINK

[SilentSeven]

Problem has not resurfaced since distributor was swapped out with a remanufactured unit.

[chaskett]

I have the exact same problem with my 2001 gt40. It would cold start fine but once I run for awhile, stop and chill, etc and crank it will start and then cut off. It always starts after 1 or 2 more try's but its annoying and I'd like to get it fixed. I replaced the IAC and it did not correct the issue.