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1994 generation 2 43 LX hard to starting engine

D

David Falter

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" I have a Bayliner with a 199

" I have a Bayliner with a 1994 4.3 Lx generation 2 engine with a Weber 4 bbl carborator in it and ever since Ive had it Ive had troubel with starting it after its warmed up and it sits for a while. If Im out fishing It will start fine in the morning, but when I get to my spot and shut off the engine for 20 30 min, when I go to restart it will start but very hard to start like it is out of gas, now if I pour some fuel in the carb first before trying to start it will start right up. Now Ive had the carborator checked and Ive had the fuel pump checked and the whole fuel system and they can't find any thing wrong. It like it gets a vapor lock or the fuel evaporates or something. I was wondering If any one alse has heard any thing like this. Ive even talked to the guy that had it before me and he all ways had the same troubel. If any one has a Idea I would be happy to hear from you
Thank you David "
 
"It does sound like vapor lock

"It does sound like vapor lock, David. Try opening the engine hatch and letting the engine idle for a few minutes after you arrive at your fishing spot, then turn off the engine and leave the hatch open while you're fishing. A breezy day would help. If the situation improves, it's most likely vapor lock.

Some possible fixes come to mind: check your thermostat and operating temp to make sure the engine isn't running too hot. Ventilate the engine bay better to move heat out. Check your fuel pressure and make sure all fuel filters are clean. Many carbs have internal filters that can clog, too. Consider installing a heat reflector around the base of the carb.

"
 
" I have tryed the letting the

" I have tryed the letting the engine idle awhile before cutting it off, does'nt seam to make a differents. Ive allways noticed that the temp the engine runs is right around 155 to 160,(I check it religiously) by the time I get to where I fish. Ive allways heard under 165 is good? A heat reflector, Ive never heard of one. Can you get at any local boat parts house. I noticed the other day that it takes time to get to where it wont start, in other words I went out and ran for a while to get it warmed up shut it off tryed it right away started right up no problem waited 10 min still ok, takes about 25 to 35 min to get to where it wont start right up. Now if i pour gas in it, it starts. All filters and seperators have been changed out and are brand new also the electronic fule pump is brand new. Allso I was looking at a manual and I noticed on that weber carb there is a check valve in side it, would that cause the gas to run back out of carb and how could I check it? Can I install another in line check to stop it from running back?
Can this be the caracteristic of this engine? Ive been trying to search to see if any one alse with this engine has had the same problem. Thank you for your Information David Falter "
 
" Hi!
Have you tried the even


" Hi!
Have you tried the even easier way of getting fuel in? I.e to pump it once before you start it warm? Also, how many turns out are your adjusting screws? If they are 2,5 or more turns out, it would not surprise me if the fuel level still is too low. The level according to manual is to be set at 1 9/32" (or just around 32-33mm:s). This is perhaps not the most technical sofisticated way but a warm engine should start right up without additional gas when warm( considering NO vapor lock exists)If it helps with a pump, this may prove a lean condition which which also sometimes can be seen in strangely adjusted adjustimg screws. To try to compensate for a lean the idle the adj.screws are way out. Even a not so large amount of difference in fuel level will
offset the quality of the idle and or starting capabilities.
Peter "
 
"Good stuff from Peter. A cou

"Good stuff from Peter. A couple other thoughts.... if your carb's float valves are not adjusted properly or sticking, it could create this condition. If the valve is an anti-siphon valve and not seating correctly when hot, then conceivably gas could be siphoning out if the valve is low enough in the bowl. That's a long shot, though. An internal leak might be allowing gas to leak slowly down into the intake manifold, depleting the fuel in the bowls. These are really just guesses, though.

FYI, many engines have a exhaust heat "crossover" passage in the intake manifold that heats the incoming fuel/air mixture to better atomize it. The downside is that heat radiates up from this crossover when a hot engine sits for a while and can evaporate fuel in the float bowls. Your operating temp is normal, and usually heat shields aren't needed so I'd look for another cure in your fuel delivery.

"
 
could it be a plugged tank ve

could it be a plugged tank vent creating vacumn in tank and actually sucking gas out of carb after engine sits a while... i am really digging deep for something to suggest. in manure?
 
" there is a fuel cut out swit

" there is a fuel cut out switch on the oil pressure sender unit ,its wont allow the electic fuel pump to start up untill oil presure builds up; u can bypass this switch by bridgeing across the two terminals thus allowing the fuel pump to fill the carby b4 trying to start .i have put a switch in the cable saves cranking engine up to allow oil presure to open circuit in elec fuel pump
( both my 4.3 motors have this problem ) "
 
sorry 4got to add ;turn insta

sorry 4got to add ;turn installed switch off after motor starts..cut out switch was put there to cut out elec fuel pump in case of oil pressure drop or engine blow up
 
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