GT-40 Fuel Pressure Regulator

[jhersey29]

I wanted to share the crazy experience I had with my 99 Ski Nautique GT-40. I've been having a intermittent hard starting issue since I bought the boat. I've been replacing the inexpensive parts(relays, fuel filter, plugs, cap, rotor, etc.) that I felt comfortable replacing since the were old and needed some love and also have been reported as known areas to address. I finally think I've narrowed down the problem to the fuel pressure regulator using a leak down test. I ordered a new one for $170.00 from a dealer online. The new one arrived and I put it on last night. It's pretty easy but smaller hands would be nice. Only 3 Allen bolts to deal with. I went to test it on the water and it is leaking like crazy. Gas is spraying out all over from under the regulator. At the lake I took it off and found 2 things strange. The new rubber gasket did not go all the way around one of the inputs/outputs and the o-ring was bad. Brand new and BAD! I think they are 14 years old based on the new box and probably dry rotted even thought new old stock. Good thing I never left the doc and made sure to check for leaks. Blowing myself up would not make for a good week. The boat started right up even with it spraying fuel all over the place. So I went to Napa and found another regulator for a Crown Victoria that looked identical and has the full washer and a new o-ring. It was only $31.65. I put the washer and o-ring on the regulator from the dealership since I am not sure the Napa one at a fraction of the price is the same as marine grade(thinking I over paid by quite a bit but not sure). I put it back together and no leaks and all seems good. So did I get burnt on the regulator from the dealer or is it actually maybe a stainless steel casing or something special? It just came in a Motorcraft box so seems it was OEM Ford. Also a warning to anyone replacing these! Make sure the new parts actually have good rubber washers and o-rings and look for leaks. Attached are pictures showing the new rubber washer from Napa on the right, New bad one from the boat dealership on the left, new bad o-ring from the boat dealership part. Also attached is a picture of my old regulator and it's bad o-ring.

[east tx skier]

Haven't had to replace that part yet. But I've done the fuel pump (outside the FCC), relays, IAC, ASV, distributor cap, rotor, wires, etc. So I'm hoping for a year of reprieve. Glad you didn't blow up.

[jrang97]

I don't mean to jump on your thread, but I recently have experienced similar issues on my 99 SN and would like some feedback.

It seems that I sometimes(not always) loose fuel pressure when the boat sits for more than 30 minutes. I was leaning towards replacing the fuel regulator after performing a leak down test today. However, I've also experienced some other issues and was wondering if you also experienced them.

1. Occasionally while idling the boat will stall out. After a few turns of the key to reprime the system it starts back up. This has probably happened 6 random times this year.
2. I was pulling a skier today and the boat just died mid pull. Again after a couple turns of the key it fired up and was fine.

So far I have done the following tests.

1. Ran the low pressure pump for around 20 seconds and found it pump 28 oz in this time. It was a little less than everyone says it should pump, which is a little concerning.
2. Pull apart the FCC and found the filter to be clean. I replaced it at the end of last season.
3. I visually inspected the small rubber hose in the FCC and do not see any issues.

Any help that can be provided would be appreciated.

[jhersey29]

On response to your topics

1) stalling - the boat never stalls. Literally never. Once it I running it was fine.
2) I also replaced the filter as part of my trouble shooting. Changing filter made no difference
3) I also inspected the hose and even bought a new one since it was only 2.00 or something like that. However I didn't buy clamps for the new hose and couldn't figure out how to reuse the old clamps. I'm still running with the old hose.

In my leak down test I was loosing about 5 psi nearly instantly. It would go from 40ish to 35. Then a slow steady drop from there. With the new regulator, rubber washer and o-ring. I get a solid 39 psi and it takes about 15 minutes to drop the pressure to 38 psi. I have also gained 1.5 mph on boat top end. In Denver the boat was topped at 40 mph. She got up to 41.5-41.8 after the fix.

Sound like you tested the low pressure fuel pump volume. Did you test the psi using the schraeder valve and a fuel pressure gauge on top of the FCC? Most of the gauges come with a kit that you can also test the low pressure fuel pump. There is T connector and extra hose that you can use. http://www.oreillyauto.com/site/c/de...0665&ppt=C0103

[jhersey29]

Fuel Pressure Regulator options I can find from local sources.

http://www.napaonline.com/Catalog/Ca...04A_0374704995
http://www.oreillyauto.com/site/c/de...&keyword=2fpr1

[jrang97]

I just tested the low pressure fuel pump by doing the following.

1. Connecting my fuel pressure regulator to the Schrader valve on the FCC
2. Disconnected the wire for the high pressure pump.
3. Ran the low pressure pump for about a minute by jumpering the STO connector.

I found that that I wasn't able to build up any pressure with only the low pressure pump running.

Next I hooked up the high pressure pump and did the same test. I measured 40 psi on the Schrader valve on the FCC. Note I replaced the regulator this morning with one from O'Reily's and I was able to pass the leak down test.

Right now now I'm leaning towards a bad low pressure pump, but I would love some feedback before I spend the time and money replacing it.

[jhersey29]

I don't think you will be able to build pressure out of the top of the FCC with the low pressure pump. The Schrader valve is fed at the top of the FCC from the HPP in the FCC. What about the check valve at the fuel tank? Based on your notes above it does sound like fuel starvation. low pressure pump isn't terribly expensive nor is the check valve. I'd take the check valve out and see if you have anything stuck in it.
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