Excalibur Problems

vtmechengvtmecheng Posts: 903 Crazy Baller
edited September 12 in Boat Talk
Ski partner has a 2004 SN 196 with Excalibur 5.7L engine. Symptoms:
-It is randomly bogging shortly after getting to speed, though it always seems to recover and go for the pass.
-At times it won't start. When this happens it is getting zero fuel pressure but disconnecting the high pressure supply line just a bit and reconnecting will result in resumed pressure and it will run fine after. Both fuel pumps are always running though this.

I took a pressure gauge to the pond and ran some tests.
-First key on and got only 20psi at the fuel rail.
-Second key on and got it up to about 30 psi.
-Releved pressure at the gauge to try again, turned key to on, and it only went to 5 psi. After that it wouldn't pressurize the fuel rail at all.
-I was about to say that the pump must be bad dispite that I could hear it run. Decided to try and disconnect that high pressure line from the pump housing and reconnect. Did that, gas started to spray into the rag, I retightened, and turned the key to on. Sure enough, the fuel rail pressure gauge shoots to 51 psi. Boat started fine after that and ran great with pressures holding nicely.
-Disconnecting vacuum from the fuel regulator brings pressure up just like it should.
-Holding vacuum at the regulator, it does not leak down.

So I'm trying to figure out what is going on here. It seems that even when the fuel rail has no pressure, there is pressure in the line between the pump and the regulator. Is it possible for the regulator to completely block fuel from getting to the rail down stream or is this some strange fuel pump problem? Let me know if I didn't explain something well and thank you all for actually reading this and any thoughts.

EDIT: Forgot to mention that we were having problems a month ago where it would stall half way through the course. Found out the low pressure pump was failing to supply enough fuel to the fuel control cell so that was replaced. I replaced the fuel filter in the control cell at that same time (this boat only has that one).

Comments

  • skier2788skier2788 Posts: 810 Crazy Baller
    First thoughts when was the last time the fuel filter was changed and was the fuel line inside the housing checked for any cracks?
    Travis Torley
  • DragoDrago Posts: 1,673 Mega Baller
    Different engine but similar problems: as @skier2788 said, check the lines in you low and high pressure pumps
    SR SL Judge & Driver (“a driver who is super late on the wheel and is out of sync”)
  • DanEDanE Posts: 934 Crazy Baller
    @vtmecheng One possibility is the hose between fuel control cell and rail is failing internally. Inner rubber tube bunching up and acts like a check valve.
  • vtmechengvtmecheng Posts: 903 Crazy Baller
    edited September 12
    This engine only has the filter in the fuel control cell and I replaced it a few weeks ago as my first thing to try. Sorry I forgot to mention that. I also forgot to mention that the low pressure pump went bad a month ago so that was replaced. I’ll update the first post with this info if I’m still in the time window for that.

    The line between the low and high pressure pump is metal so that won’t degrade. The ones between that high pump and the regulator are not kinked but it’s definitely possible that they are degraded inside. How would that cause pressure between the high pressure pump and the regular but not in the fuel rail? I know there is pressure at the regulator connection because removing the supply line there and reconnecting also works to regain pressure at the fuel rail. I would think that bunching of a degraded line would change if just wiggle the supply line and not require complete disconnection of it.
  • skier2788skier2788 Posts: 810 Crazy Baller
    Almost sounds like a vapor lock issue. Does it do it cold?
    Travis Torley
  • vtmechengvtmecheng Posts: 903 Crazy Baller
    @skier2788 it’s usually worse when cold.
  • skimtbskimtb Posts: 522 Crazy Baller
    Maybe not the cheapest fix, but you could swap engines and get ZO? Ha. I got nothing sorry.
  • ski6jonesski6jones Posts: 1,193 Mega Baller
    Not sure it fits your symptoms but my Exaliber setup also had no external fuel filter. Only the one In the fuel cell. I was experiencing fuel supply issues and surging engine. Checked the fuel return to the tank and it was barely a trickle at idle. At idle most of the fuel output should be redirected back to the tank. The hose from the tank attached to a barbed fitting on the inlet to the low pressure fuel pump. There was a screen in the barbed fitting the was mostly packed with detritus from years if use. Cleaned that screen and all was good. Added an inline filter between the tank and fuel cell to prevent recurring.
    Carl Addington, Lakes of Katy, Texas
    thagersgreggrawly
  • vtmechengvtmecheng Posts: 903 Crazy Baller
    @ski6jones so your supply to the low pressure pump was low, causing too little fuel to the fuel control cell and little to return to the tank? If that were the problem wouldn’t it always run super lean and have poor acceleration even when we do get it started?
  • ski6jonesski6jones Posts: 1,193 Mega Baller
    Maybe. Fuel supply problems can give weird symptoms. Easy to check both and zero cost.
    Carl Addington, Lakes of Katy, Texas
  • vtmechengvtmecheng Posts: 903 Crazy Baller
    I’ll definitely check the tank supply and return lines
  • jetpilotg4jetpilotg4 Posts: 340 Solid Baller
    Anti siphon valve clogged?
  • Jody_SealJody_Seal Posts: 3,469 Mega Baller
    Has the steering cable been replaced?
    Hobby Boats can be expensive when the hobbyist is limited on their own skill and expertise.


  • vtmechengvtmecheng Posts: 903 Crazy Baller
    @Jody_Seal I’m not sure what that has to do with the fuel but we have not touched the steering cable.
  • thagerthager Posts: 5,374 Mega Baller
    edited September 14
    Could be sarcasm Sheldon, a garlic necklace might help also!
    Stir vigorously then leave!
  • vtmechengvtmecheng Posts: 903 Crazy Baller
    I sensed sarcasm but also didn’t want to be a dick (not easy for me) in case some situation where a model has a fuel line right next to the steering cable and replacement tends to cause damage to the line or something.
    Andre
  • vtmechengvtmecheng Posts: 903 Crazy Baller
    Boat was running fine since Saturday so I left it alone. Today it stalls once, then runs for 12 passes. Next skier, me, it starts but runs like crap and exhaust smells really rich. Shut down and it won’t start until maybe the 5th attempt, then runs fine for 6 passes before stalling out. Now it won’t start at all. We loosened the high pressure line from the pump to see if it was pressurized and it definitely was (didn’t have a gauge with me). I’m thinking it is most likely a plugged return line or the regulator. Any other thoughts?
  • vtmechengvtmecheng Posts: 903 Crazy Baller
    And today it starts right up again. This sucks!
  • cacmancacman Posts: 119 Open or Level 9 Skier
    just a thought, The distributor cap is held down by two screws that screw into plastic. That plastic breaks. They make a metal piece that goes underneath and you screw into that. Worth checking.
  • Jody_SealJody_Seal Posts: 3,469 Mega Baller
    @vtmecheng

    Had a boat a 03 196 that a previous individual installed a steering cable tearing up the red wire that comes from the battery to the breaker box. It had the same similar symptoms as you described.
    Had to replace that wire from the battery to the breaker box. Only after hours of chasing what I though was a fuel pressure problem. That's why I asked.
    Carry on!
    Hobby Boats can be expensive when the hobbyist is limited on their own skill and expertise.


  • vtmechengvtmecheng Posts: 903 Crazy Baller
    edited September 20
    Thank you @Jody_Seal for the information and I am sorry I doubted your intentions. This is becoming a real problem at this point because the mechanics in our area are completely swamped so it’s up to us in order to finish the season. Both pumps run all the time but at times I get zero pressure at the rail. I still think there’s pressure between the pump and regulator even when the rail has zero. I’m thinking of adapting a pressure gauge T to the pump supply so that I can test that.
Sign In or Register to comment.