454 starting issues. Getting frustrated

Saverio

Saverio

Well-Known Member
Aug 31, 2010
1,506
Patchogue, Great Southbay N.Y.
Boat Info
1995 450 DA
Engines
Cat 3126 420hp
900 hours Westerbeek Generator
Hi allHave issues with my starboard motor. If the boat sits for a few days it will crank for bout ten seconds than fire. It would run fine than when I shut it down or at low rpm it might stall. It won't restart after. I have to wait and crank. It would happen on occasion last year now happining all the time nowI did a full tune up plugs cap rotor wires did last year. Even replaced coil. I just checked filter at carb and it was partially restiched I checked timing and found off 6 degrees. Thought those might have been issues. It started ran fine. I would shut down and restart with no issues. It sat for a half hour and now won't restart. It sounds like it wants to but doesn't. I'm not sure what's next. Carb issues??? I tried wiring choke wide open no change. Thanks in advance Saverio
 
Sounds like classic Quadrajet carb issues. The carb is flooding or leaking excess fuel thru the well plugs in the bottom of the carb. Unless you know how to rebuild the carb and reseal the well plugs yourself remove the carb and have a qualified carb rebuilder correct the problems. It will make a big difference. I would also recommend installing Racor fuel/water separators.
 
Do you put Stabil in your fuel tanks? You may have a sticking needle and seat valve problem in your float bowl. When it intermittently allows fuel to enter the float bowl, the engine will use that up and quit later if the needle gets stuck in the closed position. In either case, you definitely have a carb cleaning job in your future.
 
thanks Hottoddie,

I started reading the ads for rebuilt carbs and they all talk about having epoxy the well plugs. going to give it a try and pick one up.

saverio
hottoddie said:
Sounds like classic Quadrajet carb issues. The carb is flooding or leaking excess fuel thru the well plugs in the bottom of the carb. Unless you know how to rebuild the carb and reseal the well plugs yourself remove the carb and have a qualified carb rebuilder correct the problems. It will make a big difference. I would also recommend installing Racor fuel/water separators.
Click to expand...
 
I'm not so sure it is a carb issue. It could be the the fuel pump. While I have a well documented dislike for Quadrajets..... The behavior sounds more like a mechanical fuel pump having issues. Stalling at low RPMS....long cranking. If it is the carb....it has a serious leak down issue and you should notice a cloud of black smoke when the engine started. In addition, you would smell gasoline.
 
maybe the carb is leaking fuel when the engine is off and flooding the intake....when you shut the engine down look down the throat of the carb and see if any gas is leaking down the throat.....if it is you should rebuild the carb....

cliff
 
^ 6 years ago I replaced both Delco carbs with the Holley direct replacements. They always start good uses less gas and never had a problem in all this time.
 
I ordered a new rebuilt with electric choke option. should come in next week. have to find 12v with key for choke. does slave solonide have it?
 
Saverio said:
I ordered a new rebuilt with electric choke option. should come in next week. have to find 12v with key for choke. does slave solonide have it?
Click to expand...

just be sure the new carb has the same jets as the old carb......if not you can probably just switch the jets.....

cliff
 
Saverio said:
I ordered a new rebuilt with electric choke option. should come in next week. have to find 12v with key for choke. does slave solonide have it?
Click to expand...

Did you test the fuel pressure first? Auto zone or one of those places will loan-rent you one.

I have a question, mechanical fuel pump or electric? I had problems 2-3 years ago I would loose one motor after being warm. Come to find out the dam pump was no good. Drove me crazy.
 
I have had electric chokes for 2 years tied to the positive sides of the coil and no problems. Once adjusted correctly I never even touch the throttles prior to starting. The engines start almost like they are fuel injected.
 
Its like pulling a thread.....once you start down the electric road....more things need to be added. More on that in a moment. Were you able to check the fuel pressure? I'm still concerned it may be a fuel pump issue and not the carb.

Like others, I'm a big fan of Holley marine carbs....they are bulletproof.

Back to your question....electric fuel pumps have to be marine grade and need to be tied to an oil pressure switch on the engine. Typically this involves putting a "tee" in to the oil pressure port on the block that allows the existing sensor and the switch to share the same port. The purpose of the switch is to kill power to the pump if the engine shuts down. You don't want the fuel pump to continue to run if the engine suffers a catastrophic failure. So, be prepared to run wire and a new fused circuit to support the pumps. The good news is that you can use that circuit to support your electric choke.

On the subject of using the coil + wire.....the big problem is that wire is normally not fused. If for some reason the choke shorted....the wire would burn. The other argument is that it will rob volts from the coil. That said, I have seen a lot of boats using the coil wire without a problem. I wouldn't do it because of the fuse situation.
 
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