1999 SN GT40 Stalling at rpm > 1,000

[AB]

Went out today and the boat ran great for the first 4 passes through the course. On the 5th pass, when I gave it gas, it missed a few times and then stalled. It would idle, but any time I gave it gas it would surge and stall. Picked up some dry gas on the way home and ran it in my driveway for at lest 15 to 20 minutes thinking that was enough to pull through any bad gas. When I increased to 1500 rpm or so, it would just surge and die.

The boat has 400 hours, Perfect Pass, and I replaced the low speed fuelt pump 2 summers ago, probably not needed, as I eventually traced the problem to the fuel pump relay. New filter put on at that time.

Temp was solid at 160 degrees, no red warning lights or anything come on. It sounds like it is running out of gas, yet it smells like it is running very rich.

Anyone have any thoughts on this?

Thanks

[east tx skier]

My 98 did the exact same thing at the end of the 2009 season. Replaced the antisiphon valve on the top of the gas tank (attached to the fuel feed line (not the return)) and problem solved for $11.

[AB]

I was a little suspicious of that as well, but thought I would ask for other ideas.

I have an extra somewhere, as I replaced it when I finally found another problem a year or so ago with the fuel pump relay. Cleaned the old one out with solvent and it seemed to be fine anyway.

I can pop it on fairly easily to check. It is the red taped feed correct?

Thanks.
AB

[east tx skier]

It should be the same as whatever the hose is at the pump. In other words, if there's red tape at the pump, it's the red one at the tank. According to my local CC service guru, they do not come from the factory with 100% consistence on color coding or which side of the tank is the send and which is the return.

[AB]

I replaced the fuel filter. Not the fix. Still stalling out as rpm's are applied. The anti siphon is new from last year.

Aside from the high pressure fuel pump, is there a relay that controls this like the low pressure? I think I just replaced the low pressure relay last year, but I am not sure if I replaced 2 relays or one.

[east tx skier]

One other thing I was told to check by my dealer when this happened to me was the little fuel line inside the FCC. They can crack with age and cause a loss in fuel pressure.

[AB]

I can spin the high pressure pump around, shouldn't this be really tight on the short fuel line that hangs down? This is a strange looking power clamp that looks like no way to tighten, or take off and replace. Maybe I can break it off and put a regular stainless clamp on it.

I was going to hookup my battery charger leads to the fuel pump tonight to see if the pump motor would turn on, but trick or treat got in the way. The alternative would be to put the cell back together and try the new fuel pump pressure gauge I just bought at Autozone.

The thing that I keep getting back to is that it ran ok for 4 passes and then just acted up like it was starving for gas. Hard to imagine a fuel filter, fuel pump supply hose, etc., just all of a sudden causing this without some surging or sputtering on some other runs.

[AB]

I got some stainless power clamps tonight and replaced the crimped on clamps on the high pressure line in the FCC. Hopefully, I will have some time after work tomorrow to fire it up in the driveway. If that doesn't solve it, I have a fuel pressure pump that I can hookup to the fuel rail.

[AB]

Started it up and now it is leaking gas out the top of the FCC where the wires pass through. Shut it down before I could check the fuel rail pressure.

This is why I hate working on motors. One thing leads to another!!

[east tx skier]

Well there's your problem!

Sorry it's turning into chasing a ghost. Hope when you find it, it's an easy fix.

[AB]

Just ordered a new FCC from White Lake. As they get old, if you mess around with the wires, the gas seal can crack. Once it leaks, you have to replace. JB Weld for the more adventurous, but I don't mess around with gas in the boat.
Hope this is the fix.

[east tx skier]

Keep us posted.

[mrbobolina]

I did not see anywhere where you mentioned gass was not getting to the and through the pump? I presume that it is? The simple test is disconnect the hose from the pump put it in a clean container liKe a alhambra bottle that is empty. Flip the key to on and the pump fires. Do this e or three times and if the containers all get the same amount of gass problem is not likely between the tank to the pump. Assuming your injectors are not bad I would check the airflow. If your intake is sticking or the cable is catching it can basically sufficate the motor at go. You can see this by pushing the lever forward and watching the throttle body open close or get stuck.

Another thought is that it happened after 4 hours of running vs 5 minutes. This sounds like it could be vapor locking. Look for soft hoses or swollen cracked etc.

Hope this may help?

[AB]

Once I get the FCC installed, I will attempt to run in my driveway again.

The low pressure pump must be working, as it pumped the FCC up 3 times after I changed the filter, then put new hose clamps on, then the last time to check the fuel rail pressure with a gauge.

The boat ran fine for 4 passes through the slalom course, and then bogged and died on the fifth pass. Will not handle any gas above 1000 rpm. Bogs and dies. Sounds fine at idle. Checked the anti-siphon valve, and traced the fuel line again to make sure I don't have a hidden inline filter somewhere.

I can check the throttle body valve though. Hadn't thought of that.

The low pressure pump is a year old. The high pressure pump is original '99. There was no water or junk in the FCC that I could tell.

The new filter made no difference. I didn't try revving with the new clamps on the hi pressure feed line, as the gas was gurgling up and out of the FCC pretty good. Didn't want to cash in on my insurance policies yet.

[mrbobolina]

I would check your. Throttle cable closely as well. You will need another person. If you put the throttle in gear obviously the cable opens the throttle body and gives gas. If they are not working together then you can esentially cut the gas off when you hit go.

When I did my rebuild I put my cable on the wrong hole on the tranny, so when went in gear it died. That is how I learned about the throttle bodychoking the engine. I obviously caused my own headache, however in your case if the problem is after the pump there are not many variableds left. Injectors are dirty? You can get injector cleaner pour it into a bucket and let your injectors soak for a day. I bought an injector rebuilt kit on bay for like $20 on ebay when I did my motor. Takes like 1\2 hour to do.

If not the injectors not the cables, not the thrttle body and not a vacume issue at the hoses then you are looking at an ecu, or sensor challenge.

I would start by making sure your grounds for the sensors are not coroded. The power from those sensors to the grounds are really light, so a little corrosion can cause them to malfunction.

I wil keep thinking, but for the engine to cut at the same rpm Every time lends me to think something electical.

Look up a post I did on the master solinoid. I had a starting and cutting of problem a while ago and the solonoid was my culpret in combo with a loose ground.