3.0 will not stay running

[dave 7 0]

Hi guys. Hoping yall can give me some advice. 1989 model 3.0 serial # 0L023335 1989 bayliner capri. The engine will start fine if cold. After about 40 seconds it will start missing and die.Then it will be extremely difficult to start if at all and will run very badly then kill again.It sounds as if it is an ignition problem (misfiring). I changed the wires,plugs,distributor cap and rotor with no change. If i let it sit an hour or so it will start easily and idle fine for about 40 seconds and die again.I was thinking it may be the coil or module. Not sure if they will cause an intermittent problem or not.oh and on the fuel side the pump is new and the carb has just been rebuilt. No filter in line yet but i will be installing one. Thanks for any help.

 

[Scott06]

When it dies can you stab open the throttle a couple times and see a good stream of fuel coming out accelerator pump? If not I would check fuel supply/ pressure, inlet to carb fuel screen and in bottom of your pump there should be a fuel filter element either paper or ceramic. If these are clean disconnect fuel line run fuel into a container while someone cranks the engine to see if you have a fuel line restriction or anti siphon valve stuck closed.

Also when it dies check to see if you have spark at the plugs if not work back to distributor center wire and see if you have 12 v on + side of coil if no spark exists.

 

[dave 7 0]

I checked for fuel flow with fuel line in a plastic bottle. plenty of fuel and accelerator pump is working great.Checked the carb inlet filter it was clean. Didn't think about the one on the pump but ill guess its clean. I cleaned out the fuel tank when i installed the new pump and had the carb rebuilt.I had crappy spark at the plugs prior to the tune up. I need to check it when engine wont start. Also how do i check for voltage to the coil without unplugging the plug or poking a probe through the insulation on the wire? And thanks for the quick reply

 

[alldodge]

Looked up the serial number and it shows up as a 1998 not a 1989

In any case sounds like you need to get back into the carb. When cold the choke is closed and the carb gets more fuel, but in a short time the choke starts to open and the motor dies do to lack of fuel. Need the person who rebuilt the carb to try again, or better yet find someone that can get those idle circuits cleaned out

 

[thumpar]

Is this a points engine? Have the points been changed?

 

[dave 7 0]

Not a points distributor it’s electronic. Alldodge yes 98 had a dyslexic moment. I have tried with the choke wide open same result. Pumping the throttle has no effect when it starts to stumble. I’m not ruling out a fuel problem at this point but it does not sound like it’s running out of fuel. It sounds more like the ignition is breaking up and misfiring. I will try to ge a video up. Carb has been off and double checked as I had to reset the float after the rebuild.

 

[dave 7 0]

I passed a wire through the idle circuits and blew air through them when the carb was off for the float reset.