Engine runs rough, then stalls and won't start for 5 minutes

[Jimhunter]

HELP, we are going on a trip this Friday, 7/25 and I'm running out of options. I have a 1998 Sport Nautique with the PCM Ford GT-40 engine. We've owned it for 1 year. It ran great all last year, but in the last month, it has started to run rough at times. Typically, it will start the day great and then after 1-2 hours of wakeboarding, it will occasionally start to miss at 10 - 20 mph. When we slow down, it can really start to sputter and then stall. Sometimes it will start up again but other times we'll keep cranking it over without it starting. A few times today, we lifted the engine cover (not sure that helped) and waited about 5 minutes to get it to start again.
Here's what I did last week to try and resolve the problem (unfortunately, the problem still persists.)
- I put in new spark plugs. I used Autolite 764, the same that were in the engine. My manual recommends Autolite 763, but 763 seems to be discontinued and 764 is what is the referral.
- I put in a new rotor, distributor cap and coil wire. I got them from my CC dealer so they should be the right ones. I didn't see any corrosion and problems with the spark plug wires so I didn't change them.
- I had been using Regular, Octane 86 for the last year. My owner's manual says that I should be running Octane 87. So, after I put in the new parts above, I put in a bottle of Techron fuel additive and filled it with premium gas. Today, I filled the tank with mid level Octane 87.
I'm scheduled to take it to the CC dealer on Tuesday, but it's far away and he can't promise I'll have it back in time for our trip.
HELP! Your ideas would be greatly appreciated!
Jim

[jpduster]

RE: Engine runs rough, then stalls and won

if it's got last years fuel in it it may have gone off, i think fuels only good for about six months

[Jimhunter]

RE: Engine runs rough, then stalls and won

No, last year's fuel is long gone. We wakeboard 1-2 times per week and started in the spring using a dry suit this year. Last winter, I put fuel stabilizer in the fuel tank.

[AirTool]

RE: Engine runs rough, then stalls and won

How much old gas was in there and how much new gas did you add?

When was the last time you changed the fuel filter?...."Typically, it will start the day great and then after 1-2 hours of wakeboarding, it will occasionally start to miss at 10 - 20 mph." makes me think you've got some gunk in there blocking the filter after a while, then settling when the engine stops.

AirTool

[AirTool]

RE: Engine runs rough, then stalls and won

Oops...you beat me to the answer one minute before I posted the question. I must type slow.

What about the filter?

AirTool

[Jimhunter]

RE: Engine runs rough, then stalls and won

In response to 'how much old gas was in there and how much new gas did you add?'
- I followed the directions on the Sta-Bil fuel stabilizer bottle. The bottle says that it keeps fuel fresh for 12 months. Our boat was idle over the winter for 7-8 months. I can't remember how much gas I left in the boat but I followed the directions...either half or full tank with Sta-Bil in it. I don't suspect that's the issue.

I've never checked the fuel filter. I just searched and reviewed a very helpful link on the topic posted on this site in May, 2005. Here's the link: http://www.planetnautique.com.unixwe...pic&t=2964.
Tomorrow, I'll pull the FCC and look at the filter. Hopefully, it looks dirty.
How many 'things' on the engine can be causing this problem? I can't imagine the spark plug wires (which look clean so I didn't replace them) can be causing my problem. Any other thoughts or possible sources of the problem?
Thanks, in advance, for your help,
Jim

[AirTool]

RE: Engine runs rough, then stalls and won

99.9% chance it is NOT the ignition wires. You would have more chronic misfire problems and probably see problems with the wires.

When I changed my filter, I drained the bowl into a funnel/hose routed through the hull drain plug into a mason jar. Just like pickin' your nose, you'll always want to see what comes out. If gas in your area has ethanol in it, it is unlikely there will be any water in your bowl....but it is possible.

Does that system have a check engine light? I don't know the specifics of the GT40.

Try to twist the distributor and make sure it doesn't rotate which would change the base timing.

I don't know how that ignition is set up, but it could be that your ECM is getting hot after 1 or 2 hours then malfunctioning. Usually a hot/bad ECM will just kill then engine once it heats up. Can that ECM be checked at AutoZone or Advance? Others may know the answer to that one.

AirTool

[Jimhunter]

RE: Engine runs rough, then stalls and won

What's the ECM? Where is it located? How would it be tested?

Jim

[AirTool]

RE: Engine runs rough, then stalls and won

The ECM is the electronic brain of the entire engine control system.

http://en.wikipedia.org/wiki/Engine_control_unit

I'm not sure if that engine has a separate ignition module from the ECM. If so, I should have said Ignition Control Module instead of Engine Control Module. Usually the ignition module goes bad before the ECM. I'm also not sure they have automotive cousins and can be tested at the autozone.

Actually, I'm really stretching my fundamentals here because I don't know much about that configuration. I know a lot fords....and more about GM. I'm just not sure what shipped that year.

Is it carb or fuel injected?
Is the ignition original?
Is there a check engine or malfunction light? ...is it on?
Is this the gt40 generation with the known coil and module defects?

[Jimhunter]

RE: Engine runs rough, then stalls and won

I pulled off the FCC Bowl and the filter was not suspended from the fuel pump, as the instructions say it should be. It was sitting on the bottom of the bowl. Could the problem have been that the fuel filter was not suspended around the pump? Yes, it does look dirty but I'm not sure it's so dirty that it would have obstructed flow of fuel. Attached is a photo. What do you think?

I sure hope it's not anything advanced (and big $$), like the ECM or ICM. Yikes!

Answers to your questions:
- It's fuel injected
- I've owned the boat for 13 months so I don't know if the ignition is original
- There is a check engine light. It goes on when the engine is too hot. Haven't seen it go on regarding the rough engine running issue.
- there's a section in the owner's manual that addresses problems corrected by the PCM Fuel Control Cell, which include solutions for vapor lock, debris in the fuel, water ingestion and air ingestion. It says that the Fuel Control Cell eliminates these problems by eliminating vapor lock and air ingestions caused by fuel tank slosh and provides the necessary EFI filtration and water separation.

In summary, it seems that the fuel filter is the prime suspect right now. But is the filter really dirty enough to cause this kind of problem? Is the fact that the filter was not suspended around the fuel pump (it was at the bottom of the FCC) enough to cause the problem? Sure wish I could find an obvious problem. Our 5-day trip is this coming Friday!

Current plan of action: tomorrow, I am going to have the dealer overnight me a new fuel filter and then go test it Wednesday at the lake. If there are any other tests I should do at the lake, please let me know. Say a prayer that it works GREAT!

I'd appreciate any other ideas.

Jim

[jasper]

I don't have a lot to compare it to (sample size = 2), but that fuel filter looks pretty dirty compared to my limited experience. You can get skidim.com to send you a new filter over night too.

[AirTool]

That filter is pretty dirty and the paper has become a bit fuzzy. I'm not sure it is the culprit. A dirty filter is often a problem in autos. One thing to note. On my 2006, there is a prefilter screen also. It is replacable and somewhat cleanable. If the problems persist and point to fuel, you might check that also. Here are links.

http://www.skidim.com/prodinfo.asp?number=RP080026

http://www.skidim.com/prodinfo.asp?number=RP077014

Note pre-filter shows to be only for 2005/06.

You may also want to check your fuel pump pressure. There is probably a test connection. Your dealer can do this easy...he already has the tools.

Also, I'm pretty sure your filter was in place and it just stuck in the bowl when you pulled the bowl off. Mine did the same thing and I had trouble keeping it in place as the bowl went back on. But if you look at the length of the string, I'm not sure the filter has any room to fall. I didn't measure it all and maybe others can comment, but it all looked jammed up in there. Plus, how would your filter be so dirty if the gas was bypassing.

I'm still wondering about that ignition coil and module. Do you have a timing light? If not, some kind of cheap spark tester? (Don't do the pull-the-wire-off-trick.) Once everything gets hot and starts to shut down, check for spark at the coil wire. I say coil wire because you get eight times as many sparks there. If the spark doesn't keep a perfect beat when cranking, you have ignition problems and will have to figure out which part(s). You can also google how to test a coil with a multi-meter. If your coil is oozing oil, it is probably bad.

Sorry for the rambling here.

AirTool

[DanielC]

If you have driveability issues with a marine engine, always check the fuel pressure first. unlike an engine in a car, the engines computer does not have feedback on the air fuel ratio, and it just assumes that the fuel pressure is correct.

[Jimhunter]

Thanks guys for all your help. Since we leave for a 5-day wakeboard trip tomorrow, I decided to take it to the dealer to be sure that it's working right (I hope!). This should finish my need for discussion on this topic.
All the Best,
Jim

[saceone]

I had a similar this year
changed the plugs, rotor and the KILLSWITCH. the killswitch was the problem in my case.

good luck and have a safe trip