A4 starting issue - Page 2

hellosailor · #11 (**permalink**) 03-27-2009

It sure sounds like a fuel problem, but that still leaves an awful lot to look at. Carbs and their critical parts have always been problematic on boats because of the heeling and pitching motions and if the needle valve IS sticking...that would be a stopper.

I'd hate to say take apart a newly rebuilt carb (and risk making more problems or needing new gaskets in it) but from experience, a lot of rebuild shops just work too fast and don't do a good job. Of course, you really can't tell anything UNLESS you have a rebuild manual and you can check for the correct alignment and clearance, not just eyeball the valve. So if you plan to open it up--get the numbers and tools on hand to make sure you can check and measure.

When you say the fuel filter is empty, to me that says no fuel is being pumped into the carb, so the carb itself wouldn't be the culprit. Unless perhaps something was jamming open and allowing all the fuel to drain OUT of the carb, incidentally flooding the engine. (Which should leave a heavy fuel smell.)

"What's wrong with this picture?" can be a long slow game but if you start with the fuel tank and work your way to the cylinders...something IS going to be visibly wrong, in some way.

Console yourself by saying "It would be so much worse if I had to rebuild a diesel high pressure fuel pump." At least with an A4, a mortal with an ordinary tool box CAN fix it all.

bubb2 · #12 (**permalink**) 03-27-2009

I going with the Carb float. I used to have a old Pontiac that every time I went around a corner to fast the motor would die (out of Gas). A whack with a screwdriver handle to the Carb bowl and all was good.

scottfree · #13 (**permalink**) 03-30-2009

Beasutiful weekend.Cold fron came through Saturday. Did not get out as winds would have been "uncomfortable" according to the wife. For me I'd just as soon reef down and go but there was plenty to do on teh boat in the slip. Engine is faithful everytime I start it. I was wondering about putting a solenoid valve in the fuel line. This would do the same thing as manually shutting off the tank valve except it might be better aas I could put it in farther down the line. Ideas of where to put it? Between the racor and the tank? Between the Racor and the fuel pump. Between the fuel pum and the carb?If there is a tendency for the boat to "leak back" to the tank while sailing(one theory) where would be the best place? Aftwer work today might be a chance to get out for a short sail as wether is supposed to be nice and wind is supposed to be out of SW which will allow for ssailing back to slip if engine does present a problem. If so, I will sail with fuel valve off and see if that helps.

Any ideas what to do for posting photos. I tried and even after the resize it will not upload.

hellosailor · #14 (**permalink**) 03-30-2009

Solenoid valve in a gasoline fuel line?

Personally I wouldn't. The valve has two more fittings (inlet and discharge) that can leak or bleed, plus the electrical parts to fail, plus the "plug" itself to leak.

More reliable just to have an unbroken fuel line going back to the petcock on the fuel tank.

capn_dave · #15 (**permalink**) 03-30-2009

You shouldn't need to put another valve between the tank and the engine. Thinking of that and you mentioning the fuel has a tendency to go back to the tank. Is your tank vent working? Make sure it is not plugged. That could cause the fuel to go back to the tank. If the engine wont start today, remove the fuel fill cap and listen for a hissing sound. If you hear that, you could have a vent plugged. Usually mud dobbers are great at plugging up small holes

Fair Winds

Dave

scottfree · #16 (**permalink**) 03-31-2009

Yes, the vent is clear. I have dismanteled the cabinet on the stbd side to get to the tank. I disconnected the vent line and blew through it. It was pretty clear except for a little water which may have been at the bottom of loop.I put it back.Next I will take the tank out to inspect and clean. I am suspect of what might be in the bottom so I want to eliminate that too. I may replace lines while I am at it. The fuel line actually looks pretty good. It is fairly stiff and it is a rubber line with braided cover.
I'll cross these bridges first and see if there is improvement. Thanks for your help and interest.

ows1id · #17 (**permalink**) 04-07-2009

I would suggest using a small amount of starting fluid to determine if the problem is fuel or electrical in nature. That way you can narrow down the possible issues, and work on the right problem

floatsome · #18 (**permalink**) 04-09-2009

Make take your question to the A4 forum at Moyer Marine Atomic 4 Community - Powered by vBulletin

scottfree · #19 (**permalink**) 04-13-2009

Hope everyone had a good easter. Beautiful weather here but could not get to th boat.Previous weekend I got out. The engine started at the slip, motoring no problem. Wind was good to allow sailintg back if needed so we were off.
After 2 hours sailing in 15 -18 with 3' to 4' seas we headed in. I had the fuel valve off while sailing. The engine started and ran for about 5 minutes. It stopped as if i had turned the key off. Just about into the channel coming in with shallows on both sides. Oh crap! The engine resatarted after a a few minutes. I think now that the issue of fuel to the racor and carb is solved but now i think there must be some junk in the bottom of the tank. Previously I had to remove the fuel fill hose from deck to tank to remove the countertop over the tank. In the process I found the hose to be dried and brittle, to the point literally of crumbling as I twisted it to take off. Now I am thinking there must be some of that and/or other debris in the tank that the pickup sucks up. If the engine stops the suction stops and it can fall off once again freeing the pickup. Job for this week is to remove tankl and clean/flush. I am anxious to see what comes out of it. At this point i don't know what else it could be. I may chane the fuel line while I am at it since it is such a pain to get to to do later. More on this later after tI find out what is in the tank other than fuel.

cnc33voodoo · #20 (**permalink**) 04-13-2009

Spark plugs will tell the story of why its not starting, the proof will be in what the plug looks like.
If you still are running a mechanical fuel pump you might want to check the diaphragm.if not replaced, they tend to break down after long engine running and cause restart issues.
if you go on moyer marine'e site you can buy a repair kit or go electric.
Moyer Marine Online Store