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View Full Version : PCM 351, Not getting fuel


jmcentire
08-24-2008, 05:53 PM
Boat (85 190 w/PCM 351W, EI) was running great last time we had it out, absolutely no problems, seemed like it had full power. Then we got busy and weren't able to take it out again until today(about a month later). Backed down the ramp and the engine turns but won't fire. Start looking around and there is definitely no fuel getting to the carb. There is one of those see through filters between the pump and the carb and it was completely dry. Then I spun off the filter between the tank and the pump and it was completely full of fuel. So the thing that has got me stumped is usually if a filter is getting plugged or if a pump is going out you will notice before the fuel supply is completely cut off, but maybe that month of sitting caused a problem? What do you guys think?

Thanks

WilliM1940
08-24-2008, 06:27 PM
Aside, the see through filter is not an approved installation, that section of the fuel line should be metal. Dump some fuel down the throat and see if the engine fires, if it doesn’t check for spark. If your diaphragm pump failed, there should be gas visible in the tygon tubing from the pump to the spark arrestor. If you suspect a problem in the fuel system supplying the pump, separate it and try a substitute tank. Have you changed out your rubber hose from the tank to the fuel filter? If it is original, it is due. Filter element replacement should be done every year or two.

jmcentire
08-24-2008, 10:06 PM
Yeah, that see through filter was there when I bought it, just haven't got the replacement metal tubing ordered yet.

No fuel visible in the tubing from the pump to the flame arrestor.

I will be getting a new filter tomorrow, however the one that is on there I don't believe is OEM either, it looks like a remote mounted spin on oil filter, when I spun the filter off it is a single piece metal filter(looks very similar to an oil filter), and says Fuel Filter/Water Separator.

ski_king
08-24-2008, 11:29 PM
The fuel pumps on the 351's can fail in weird ways.
On mine the diaphrams fell out of the seats and I fixed it twice by simply reseating the diaphrams. Both fixs lasted over a year.

Tear the pump apart and check it out or better yet, buy a new one (http://skidim.com/prodinfo.asp?number=RA080002A).

RadarDad
08-25-2008, 09:29 AM
I was having fuel supply problems with my 88, 190. It turned out to be the check valve on the gas tank. Try putting a straight barb with no check valve and see if it gets fuel. It helped me.
Roger

Gamble
08-26-2008, 02:36 AM
I have an 83 with the 351w and ei.........and I don't have a metal hose for fuel anywhere.....never have. I can tell you this, I had to replace the fuel pump due to the same situation........about an hour job for me, and it now runs great. Hope this helps you.

jmcentire
08-27-2008, 04:45 PM
Got a new pump ordered, should get it tomorrow, I pulled apart the current one and it doesn't seem to be in very good shape. Also I decided I would change out all the fuel lines while I was at it(I also ordered a metal line from the pump to the carb), good thing because the line that goes from the tank to the filter in the engine compartment was pretty much falling apart when I was pulling it off.

Anyway my question now is do I need to get the USCG approved fuel line from a boat shop or will an automotive fuel line be fine?

Thanks

jmcentire
08-27-2008, 06:34 PM
Well, did some searching and found the price wasn't much different between automotive and USCG A1, so might as well be in compliance.

FYI Boater's World has 3/8" USCG A1 Fuel Line for $1.87/ft.

EricB
08-27-2008, 06:46 PM
You also can test the mechanical fuel pump by pressure testing (output side) or by a suction/vaccuum test (input side). Pressure spec is 5 to 6 lbs. (pg. 13 of PCM Manual).

Pump should generate at least 6" Hg vaccuum.

jmcentire
08-28-2008, 08:44 PM
Well, got the new pump and metal fuel line, now the problem is my carb fuel inlet is a banjo bolt. Anyone know where I can get a fitting that will go from the metal fuel line to the carb inlet? I think I might be able to make something work from a hardware store, but I don't think the little screen filter will fit in there anymore. What do you think?

WilliM1940
08-28-2008, 09:24 PM
Banjo bolt? Try www.skidim.com for the parts, assuming you have a 4160 Holley.

Hollywood
08-29-2008, 10:25 AM
I have an 83 with the 351w and ei.........and I don't have a metal hose for fuel anywhere.....never have.

That doesn't make it right. Replace with an approved line, do not put your passengers' safety at risk.

jmcentire
08-29-2008, 12:48 PM
Well, after doing more research it looks like my current carb was a replacement, and the person who replaced it got a universal Holley 4160 marine instead of the one designed for the 351W. You can see in the attached pictures the differences in the fuel inlets, and mine has a banjo fitting(last picture) screwed into the inlet on the universal one. DIM has a part to change to the correct inlet but it is the entire fuel bowl, so it is like $80. So it's looking like I will be using a rubber hose(will change to USCG Type A1), until I save enough to just get a whole new carb(this one has some problems anyway), or if anyone has an extra used one I will buy it off you, I already have a rebuild kit.

jmcentire
08-31-2008, 08:04 PM
Got it all back together, but now I have problems, the engine will run at about 1/3 throttle with about 1000 rpm, any less and it dies, also while sitting at 1/3 throttle the rpms jump around from 800-1200 rpm. I checked timing even though I didn't touch it, and it was right on at 6 BTDC. So the only thing I have done is change the fuel pump, fuel filter and fuel lines. Any ideas?
Thanks

JimN
08-31-2008, 08:31 PM
Make sure it's not sucking air.

Gamble
08-31-2008, 08:57 PM
That doesn't make it right. Replace with an approved line, do not put your passengers' safety at risk.

Simply put......I don't have a metal hose, and it runs great, and has for 25 years. The point to the entire statement was if his didn't have the metal hose, it's quite probable that that wasn't the cause for the problem.

jmcentire
09-01-2008, 01:01 PM
Make sure it's not sucking air.

The fuel pump? If that's what you meant, it is definitely pushing fuel. Actually it seems like it is getting too much fuel at idle, not sure though.

Cloaked
09-01-2008, 01:43 PM
Well, got the new pump and metal fuel line, now the problem is my carb fuel inlet is a banjo bolt. Anyone know where I can get a fitting that will go from the metal fuel line to the carb inlet? I think I might be able to make something work from a hardware store, but I don't think the little screen filter will fit in there anymore. What do you think?With regards to the specified 4160 above (in lieu of the general application) ....there lies the purpose of the short rubber piece in the fuel line. Allows for adjusting the radiator bearings and connections of such. I think I recall having this issue many years back and did find an adaptor to connect, and that is when I put a short piece of flexible marine fuel line on the metal line. Never had threading issues again when realigning the coupling or threaded connections. I recall finding the adaptor at a hardware store. I wouldn't sweat the screen at that point since it's downstream of the fuel filter.

Flexible fuel line is perfectly fine.

JimN
09-01-2008, 01:44 PM
Add some fuel when it's struggling. If it improves, it's lean. I use an old mustard bottle and squirt it through the flame arrestor. It's easiest if you have someone else drive the boat when you do this. Keep a fire extinguisher close, just in case.

jmcentire
09-03-2008, 12:46 PM
It seems that the problem is solved...hopefully(I didn't get to do a lake test and I am heading to Lake Powell later today).

What seems to have happened is when the fuel pump failed something happened to the carb as well. After I replaced the fuel pump and the carb was getting fuel again, the carb was flooding the engine, after messing with it for a while and flooding the engine worse I rebuilt the carb. After I put the rebuilt carb back on it was running better but not great and it was smoking like crazy. Checked the oil and all that gas from the carb flooding seeped down into the oil, so changed the oil and it is finally idling without throttle...seems a little rough but i think it always seems to run rough in the driveway.

Anyway I'm off to Lake Powell, hopefully it will be running when I get there:D.

JimN
09-03-2008, 01:25 PM
You might want to change the oil again but that does make a big difference. Running it with gas in the oil really cuts the lubricity of the oil but I don't remember you saying that you ran it hard, so it probably just cleaned things up a bit.

Hollywood
09-03-2008, 01:30 PM
Simply put......I don't have a metal hose, and it runs great, and has for 25 years. The point to the entire statement was if his didn't have the metal hose, it's quite probable that that wasn't the cause for the problem.

Simply put.....I didn't recommend changing the fuel line to solve his current problem. There are flexible approved lines, I hope yours is one of them.