1998 - 196 Nautique surging under load

[hoopdog]

Hi all,
Having problems with GT-40 98 model 196 surging under load. Tacho is bouncing around the 2-2500 rpm and boat struggles to go over 25mph.

I have changed plugs, leads, hook up to compter and no errors codes appeared. I changed fuel filter and even ran some injector cleaner.

I was thinking it could be either the ingnition coil or injectors?

What should I do??

Hoopdog

[BT]

You need to check fuel pressure while the surging occurs. You can buy a fuel pressure test kit that will work at most automotive stores. Ask for a fuel pressure tester that will fit mid to late 90's fords.

[hoopdog]

Thanks BT. I will give it a try

[Johnsongc]

Sounds like it is being sent into limp mode. Is the red warning light coming on?

I had a similar problem with my friend's '98. It turned out to be a bad oil sensor.

[hoopdog]

Hoopdog

Na, no engine light coming on. I think it is the injectors? What do you think?

[Rick]

Low pressure fuel pump

I'm betting on the low pressure fuel pump starting to go. As recommended before check the fuel pressure.

[DanielC]

Let me stress the importance of knowing what the fuel pressure is. The computer does not have any feedback from the engine on the fuel to air ratio, and just assumes the fuel pressure is right.

This is how to check the fuel pressure:
http://www.planetnautique.com/vb3/sh...=Fuel+Pressure

[hoopdog]

Pulled the injecters out and they look pretty dirty. The little filters look pretty clogged.
Only took an hour to get them out and will only cost $320 australian to get professionally cleaned.

I hope it works....

[hoopdog]

HI All,

Just got a call from the injector guys and the flow rate was good but the injector spray pattern was bad. Also, one of the injectors had a leak.

Hopefully, pick them up today and will put them in on Saturday and take it out for a spin.

If still playing up, then I think the possible cause will be the water temp switch.

Has anyone had this go in there 98 GT40? If so, what where the symptoms and can you test them?

Cheers
Hoopdog

[hoopdog]

PCM GT-40 Still Surging

Hi Guys,

Took the boat out yesterday after changing Spark Plugs, Leads, Coil, Injectors and distributer cap and my boat is still surging. It struggles to accelerate on open throttle aswell.

I run 98 octane fuel and have test fuel pressure with boat is on tralier and reving it to 2500-3000 rpm. Fuel pressure is ok.

This only happens when the boat is in the water and under load?

I have tested the computer and no error codes have appread.

Does any one know what I should do next? Burn the boat perhaps??? (Only joking)

Thanks
Hoopdog

[east tx skier]

My 98 would die on acceleration and it turned about to be the antisiphon valve. Mine never surged. It just died when I gave it too much gas.

How dirty is your flame arrestor?

[jjgag60]

Surging

Try hooking up the fuel pressure gauge while you are running the boat underload to see what is happening.
98 percent of problems with the Gt-40 are fuel related. You checked your fuel filter to see if you have any water in it? You might also replace your fuel relay's they cost about $11 each

[eseybold]

I had a similar problem

I had a similar problem on my 2000 SNOB with GT 40...... and did everyhting that you did and changed my low and high pressure fuel pumps. Still no luck. I too was ready to burn my boat. One day I decided to start the engine on the trailer at night and inspect for leaking spark....... .sure enough one of my BRAND new spark plugs had a crack in the porcelain and it was leaking spark to the engine block that I could not see in the daytime. I replaced the plug and it was fixed. Took me 2 years and about 600 dollars in parts to figure it out !

[hoopdog]

Thanks Guys,

I will take the boat out for another run on the weekend and see if any of your suggestions work?

I still think it is electical somehow

[JUST-IN-TIME]

did you have the fuel pressure gauge hooked up while under load?
what computer program are you using>