GT40 intermittent idle problem

[Chexi]

For anyone with that Amazon/ebay star tester clone, could you post a picture of it hooked up to the engine? I have one, but don't know where / how to hook it up. Thanks.

[Lewy2001]

Chexi this should help.

http://www.youtube.com/watch?feature...&v=zqCiyw41zMY

[Chexi]

Thank you.

[boo]

Finally the solution has been discovered. Our local independent boat mechanic connected a fuel pressure gauge to the fuel rail and then proceeded to use a pair of slip joint pliers and slowly crushed the fuel pressure regulator until the fuel pressure reached its maximum tolerance.

It's been 6 months since he "squeezed" the fuel pressure regulator and the oscillation has only occurred twice and not bad enough to turn the engine off and then on again. The idle evened out on its own.

In all fairness to the Nautique dealer, crushing the fuel pressure regulator was one of the options he recommended back in 2012 at the time of my first post. It was my choice to leave it as the last viable option. It turned out to be the solution.

[jhersey29]

What did crushing it do? Why wouldn't he just replace it with one that correctly manages the fuel pressure?
Sent from my RM-877_nam_att_205 using Tapatalk

[boo]

One local friend that owns the same boat that's one year older did replace his fuel pressure regulator and the symptom did not go away. My guess, and this is only a guess, when the GT40 engine ages (ours has 1,400 hours on it) a new fuel pressure regulator does not function well on it. I honesty can not remember when the oscillating started. It was well before my first post so I don't know how many hours were on the boat at the time.

To answer your question specifically as to what the crushing did, I don't know because I've never seen the inside of the fuel pressure regulator.

I can say with absolute certainty, the problem is fixed. We've used the boat many times under the same conditions that should have made the idle go up and down and it has not.

[jjgag60]

can you post a picture of what your regulator looks like after being crushed? Or can someone describe how you can do this?

[boo]

A photo would not show any difference. The crushing was very slight. One correction. It was a C-clamp that was used not slip joint pliers.

[jjgag60]

Thanks, when he squeezed it did he do it from side to side or do you know? It is interesting I cant find any mention of doing this anywhere else

[boo]

Top and bottom. Not the circumference.

[Pumpe]

Did he crush it out on the edges or in the mittle directly on the pipe that goes to the plenum, a Picture with some arrows would mean a lot to me as I have the same issue

[BigBen_UK]

There's a spring inside the FPR, so crushing effectively increases your fuel pressure by squishing the spring a bit - not something you can do without an accurate pressure gauge attached - it can't be un-crushed so if you increase the pressure too far you're stuffed. I'd be looking at other components if my fuel pressure is on spec before resorting to this.

[ShouldbeWorking]

... I'd be looking at other components if my fuel pressure is on spec before resorting to this.

I agree. Seems like a janky band aid. It doesn't really fix the problem, just mask it. If the fuel pressure isn't staying at 60ish, it would seem like he's on the right track for actually solving the problem properly. There's only so many components from the gas tank to the motor.

[boo]

I'm the author of this post and squeezing the regulator worked. The oscillation is gone and has not returned. Sorry I don't have any photos. The squeezing was done from the top and bottom, not the sides.

The procedure was performed on July 2015 and its now December 2016. We use the boat all year here in San Diego so I can truthfully say the engine has been turned on and off many, many, many times in the past 1-1/2 years.