Fuel Pressure Regulators

[pascavone]

on pre -2000 fuel injection, the ethonal would eat the rubber o-rings in the fuel injectors, on boats and on cars. So much so the nissan replaced all my car injected harness on an 11 year old car because of leaks and fires.

metal is not painted, that is in contact with fuel.

[ss3964spd]

Tom,

Our 2004 has an MPI engine with only about 182 hours on it. Has had nothing but ethanol blended gasoline in it since we've owned it and probably a good bit of it before we aquired the boat with 74 hours of run time. It has sat unused, winter after winter - 5 or 6 months at a time, with ethanol gas sitting in the entire fuel system. Sometimes the tank has been near full, other times only 1/3 full. We've never had a fuel system problem. Not once (Of course I'm sure I'll have to eat those words upon start-up this Spring!).

Like Pas said - no painted parts in direct contact with the fuel. I just cannot imagine that a fuel system designer/engineer would make such a specification. I'm pretty confidant that whatever your mech found in the screens isn't paint. Perhaps it's bits of one of the up-stream filters coming apart.

I did the same search as you and came up with the same info as you. Basically - nothing that supports paint in the fuel system. To the best of my knowledge there's only one point on an MPI equipped engine from where to measure fuel pressure - the valve on the fuel rail after the regulator. Just makes no logical sense that a blockage down stream would result in higher pressure on the fuel rail.

Regardless, whatever the true cause it sounds like you've got it sorted out now. Will be interesting to see what your flow scans tell you.

Dan

[iceman]

Dan,

All of that makes sense. Wish I could figure out where the "debris" came from. My fuel system worked fine for the entire 2010 season. Towards the end of that I had the Floscan installed. The problems started at the beginning of 2011. Maybe some junk got in the system during the Floscan installation ... or maybe I got some bad fuel at some point.

At any rate, I'm anxious to try it out, but I probably won't be able to splash it until April. I hope it's fixed, because this season I'm planning on some longer cruises, and better fuel economy will help.

Thanks for your help and advice!

Tom

[shrew]

I didn't catch what year the boat is. If it's pre-ethenol, then debris could be the inner lining of fuel lines flaking. It could be gunk from the tank. The Merc service bullitin seems to indicate debris from corrosion. I'd be more inclined to think the mechanic mistook the debris as beign paint. Maybe the corrosion in the bullitin is really paint overspray and they are trying to sugar coat it.

[iceman]

OK, I was thrilled to have good weather this past weekend and so I launched for the first 2012 cruise. As a result I have an update to this thread, and I'm happy to report it looks like the fuel system is indeed fixed and the engine is running like a top. I need to sit down and do some calculations from the chartplotter data, but from the Floscan alone, when on plane I was burning around 12.8 GPH at around 23 knots. Using advanced calculus, that works out to about 1.8 nm/gal or 2.0 mpg. This is pretty close to the fuel economy I believe I was getting in 2010, where last year the Floscan read between 14 and 20 GPH under these conditions. So, whatever the source of the problem, it appears fixed. I wish I understood the root cause so I could take preventative measures, but at least now I have a solid baseline to evaluate future performance against.

This weekend I took the family to Pier 39 in San Francisco, and stayed in a guest slip for 2 nights. SF is always hopping with action so it's pretty hard to get bored. Friday we watched the taping of a television show called "America's Got Talent". Saturday there was a "Polar Plunge" where folks dressed up in costumes and jumped in the cold bay water. That was a pretty wild sight. On the water, we cruised around Treasure Island near the Bay Bridge, saw some porpoises (?), and cruised through the Alameda Estuary. Flat calm water, so a very nice ride. Can't wait for the next chance to launch!

Tom

[seapuppy]

Tom
thanks for the report out....sounds like the bay really cooperated...we used to live out that way many yrs ago and always loved seeing SF bay....and the city.....I used to work at Mare Island navshpyd.....always interesting to say the least...


SP

[ss3964spd]

[iceman]

SP - yep, I'm familiar with Mare Island. My wife was born and raised in Crockett which is right on Carquinez Strait. One planned cruise this season is up into San Pablo Bay, where we would pass Mare Island on the way into the Carquinez strait, then we would berth at Benicia and hang out there for a day or two.

[capav8r]

I missed this post....Actually, I have first hand knowledge that the inside of the cool fuel modules are indeed painted. A co worker has an 05 four winns with the 6.2 MPI and had fuel problems. The mechanic discovered that the paint was coming off the inside of the module and had clogged the injectors, filters, etc. His boat had the classic symptoms of a bad anti siphon valve at the tank-when he would drop the hammer, the engine would start to come up, then starve after a few seconds. The boat was out of warranty, but merc decided to replace the cool fuel module and injectors for him. I would believe it either had I not went with him to the shop and saw it. It looked more like the casting was not masked properly and half of the interior was painted. There was a clear line where the paint was and where bare metal was. The mechanic told us that the "new" cool fuel module indeed addresses the paint problem and that merc does not want the public knowing that they replaced his module and injectors.

[iceman]

Capav8r:
Thanks for weighing in on this, I really appreciate it. This is the first corroboration I've gotten for my mechanic's diagnosis. Furthermore, It gives me a reason to call Mercury Marine and try to at least get the cool fuel module upgraded. I had to pay for two repairs that are probably both related to this problem - the fuel pressure regulator last year and the cleaning and filters this year. It just didn't make sense for an engine with less than 100 hours on it. Fortunately the invoice I have from this year specifically mentions cleaning out the paint debris.
I will post updates as I have them.

Tom