GT40 quit but still starts when cold

KENO wrote: How's that alternator alignment issue treating you? It must be time for an update on that

Wanted to let everyone know...after replacing the LP fuel pump the boat continues to run exceptionally well. No issues for several weeks and lots of hot and cold starts. I believe that was the issue, and the one I got from Summit Racing was very easy to install. 

Gary, 

Replaced the LP fuel pump with the CarterP4389. Picked it up at Summit Racing for $82. Spliced the wires with crimp connectors that shrink wrap. Made a good connection.  I ordered a fuel filter for the FCC canister and replaced that as well, since it has been 5 years since I changed that one. 

Leave the fuel pressure gauge hooked up and tie it to something so it does not do damage or get damaged.  Go ski and play in your boat.  If the problem comes back you can do a very quick check on your pressure at that time, you could also see if it is losing pressure while parked hot.  Your first pressure drop test is fine but see what it does out on the water, it may change when hot.  Good Luck.

When the boat will not start, feel the coil and see if it is hot.

As already advised, check the pressure before buying any new parts.  Those old Carter designed low pressure pumps are tough and last.  They powered nearly every Motorhome for years till those same Motorhomes switched to fuel injection or diesel.  Sometimes they need to be cleaned if the pump sits for long periods between use but other than that they are reliable.  If your fuel pressure gauge shows low pressure that will start directing you what to work on.  Warning do not test the fuel pumps dry, they are fuel lubricated and will burn up in just seconds of dry use.  It is so tempting to hook up the power and test one before install and that is fine if you supply fuel to the inlet so it gets lubricated while you test.

https://www.summitracing.com/search/part-type/fuel-pumps?fr=part-type&SortBy=BestKeywordMatch&SortOrder=Ascending&keyword=carter%20P4389%20fuel%20pump

MurphyCO wrote: MrMcD wrote: Start with verifying your fuel pressure while it is running.  Leave the gauge hooked up and run the boat, if it dies again check your pressure while it is dead.  Cycle your key on and off which should activate your fuel pumps with each time the key is turned on, it will only power the pumps for three seconds with each turn of the key if the engine does not start.  Pressure should be around 40 psi. Thank you! I have a fuel injection pump test kit; do I test at the relief valve / test point on the FCC body? Allen screw?

cboland wrote: I also agree this could be a low pressure pump failing. Mine did this as well. It would work fine when cool, but not pump anything when hot even though you could hear it power up. Check your fuel pressure with a gauge to confirm. I replaced with the Carter mentioned above. Works like a charm.

I bit the bullet this year and replaced my already 26 year old hoses and checked my valve as well. Have not had any trouble but just wanted to check. I was able to get the correct hose at O'Reilly's in a day. My LP pump was changed 8 years ago so I'm not worried about it but I might get a spare just to have one.  

MrMcD wrote: Start with verifying your fuel pressure while it is running.  Leave the gauge hooked up and run the boat, if it dies again check your pressure while it is dead.  Cycle your key on and off which should activate your fuel pumps with each time the key is turned on, it will only power the pumps for three seconds with each turn of the key if the engine does not start.  Pressure should be around 40 psi.

After 5 very successful and fun years, my 99 Air GT40 finally is giving us grief and my wife is not so trusting. (our lake has little traffic often and cell phones don't work....blessing and curse) Anyway, the engine started and ran great all season till yesterday when it bogged down and then quit. We were towed in and put  it away for the evening. Next day, started right up. Filled the tank at the marina (it was only down a quarter or so) running great. Tried to start it two hours later and no luck at all. Sounded like a fuel issue, and I read that vapor lock can happen so I loosed the fuel filler cap. (was a bit tighter than usual, but this didn't work.