2003 Ebbtide Mercruiser 3.0 engine rattle? Normal?

[Scott06]

Yes, remove plug to disable shift interruptor

The TBI has an IAC which "should" control idle air flow. The OP mentioned about giving it more throttle and it didn't stay running, or at least I think he said something like that

This is a carbed 3.0 not TBI

 

[alldodge]

This is a carbed 3.0 not TBI

Yep my mixup with another thread

 

[nola mike]

no when i unplugged cylinder one to test out spark it ran and same for last cylinder. so 3 cylinders. Yeah im thinking maybe one or more of my plugs or.cables are bad .

So if I'm understanding correctly, unplugging a wire from either cylinder 1 or 4, the engine ran the same? That's essentially a cylinder drop test, and would point to either 2 dead cylinders or a timing issue (if the engine is actually running; if it just sputters for a few seconds that's tough to interpret) I'd triple check that your Firing order is correct and that your distributor isn't 180' off (not sure if it would run at all in that case on your 3.0). Also check your compression.

 

[ilove2fixx]

He says he has spark, i assume this is to disable the shift interrupt?
wonder if the idle stop screw is too far out and throttle blades are completely closed?

yeah i turned it where its open just a but like 1/16 of an inch maybe less

 

[ilove2fixx]

Disconnect the plug on the right (has 2 white and 1 black

ill try that

 

[ilove2fixx]

ok i got it to run by adjusting the idle mixture screw turned it counterclockwise about 2 times and it ran!! But rough and high idle over 1000rpm even after couple min of running. Also its hard to start up again unless i pump it couple times? I can hear and feel the fuel line every 2 or 3 seconds ?? is that normal?

 

[Grub54891]

ok i got it to run by adjusting the idle mixture screw turned it counterclockwise about 2 times and it ran!! But rough and high idle over 1000rpm even after couple min of running. Also its hard to start up again unless i pump it couple times? I can hear and feel the fuel line every 2 or 3 seconds ?? is that normal?

No.

 

[nola mike]

What's your choke doing? Is it tks?

 

[ilove2fixx]

What's your choke doing? Is it tks?

its fully open all the time well after couple mins of me turning the ignition. I have a feeling its like fuel restriction maybe i forgot to put that spring back in the fuel inlet to the carb or that needle/float is giving me an issue maybe ?

 

[ilove2fixx]

No.

its more like vibration every couple seconds ? is that how the fuel pump works ? sends fuel every couple seconds to the carb ?

 

[Grub54891]

You can't feel the fuel pump to determine if it's vibrating. I've never felt it.

 

[alldodge]

its more like vibration every couple seconds ? is that how the fuel pump works ? sends fuel every couple seconds to the carb ?

The pump should turn ON while the motor is cranking. Once it starts the key is released and pump shuts OFF until oil pressure builds and then it turns back ON.

The time from start to run is very short, but pump should run continiously.

maybe i forgot to put that spring back in the fuel inlet to the carb

If the filter was put in backwards it can cut fuel off. Pump the throttle and see if fuel squirts

 

[ilove2fixx]

The pump should turn ON while the motor is cranking. Once it starts the key is released and pump shuts OFF until oil pressure builds and then it turns back ON.

The time from start to run is very short, but pump should run continiously.


If the filter was put in backwards it can cut fuel off. Pump the throttle and see if fuel squirts

fuel squirts fine but its just weird why im hearing that and feeling the fuel line buzz every couple seconds maybe some restriction in the carb causing build up of pressure ? Also how can i fix that high idle, i tried fiddling with the idle mixture screw and the other idle screw at the linkage but couldn't get it under 1k rpm. Also what causes it to not start again unless i pump it ?

 

[alldodge]

Look at the idle adjustment screw on side of carb where the throttle cable is connected.

The marine carb doesn't have a return spring, the cable is what moves it to idle.

Take the cable off carb and then adjust idle screw. Once its down, adjust cable barrel is it just slides on , remove again and turn barrel one more turn so it holds the carb closed

 

[ilove2fixx]

i noticed what appears to water droplets in the carb . Or can that be condensation from all the attempts to start her up?

 

[ilove2fixx]

here is a video of what appears to be water ?

 

[Grub54891]

I'd say that's just condensation from starting. When the air runs past the plates it's normal. When the motor warms up it don't do that much. I had a car that would freeze up when colder out and the throttle would stick due to the condensation, making ice. After warm up it was fine.

 

[ilove2fixx]

I'd say that's just condensation from starting. When the air runs past the plates it's normal. When the motor warms up it don't do that much. I had a car that would freeze up when colder out and the throttle would stick due to the condensation, making ice. After warm up it was fine.

oh ok now to try the cable throttle adjustment what alldodge mentioned and hopefully that fixes it!