Idle and cold running issue 1995 4.3 carb with alpha 1

[1995SeaRay195]

1995 Sea Ray 195 mercruiser 4.3 carbed

I am trying to resolve this myself.

Engine will not stay idling unless i have rpms high.
Engine often dies when giving it gas when cold.
engine recently stopped when going 30 mph.
all my issues are in first 5 mins.

i had a new fuel pump last year.
i use ethanol free 89, use stabil marine if i do use ethanol, also use techron and or sea foam.

engine turns up 5000, runs almost 50mph. Have had 3 full tanks of gas through it.

Has anybody had this issue, at first im thinking choke, than i was thinking accelerator pump until it died without touching the throttle. Now im thinking IAC.

does the choke have a spring that heats up that can go bad?

i really dont think i need a carb rebuild. Again, i only seem to have issues when cold.

im going change out fuel water seperator but i dont think its that.


thanks for help.

 

[Bt Doctur]

If you have a carb, you dont have a IAC, if you have a throttle body EFI, you dont have a carb
So, exactly what do you have on top of the intake manifold?

 

[1995SeaRay195]

Flame arrester and 4 bbl carb.

 

[Bt Doctur]

most likely the Rochester or Weber both should be using electric chokes. On a stone cold motor the plate should be about an 1/8 inch open. You can use a 1/8 drill bit for this.. When the key is "on" voltage is supplied to the electric element to open the choke plate
Trying to give too much throttle on a cold motor will stall it and the accel pump may not be squirting a good stream either.
The shutting of a speed can be a electrical problem or just a loose engine harness plug clamp.

 

[1995SeaRay195]

Thank you for your help. Im going go check out my choke situation and give you feedback. Also, see where my idle is at and if i need to turn it up alittle. Appreciate your help.

 

[gergAlicious]

Idle speed on my 4.3 w/2bbl is 650RPM

Good luck!!

 

[1995SeaRay195]

Here is the update, I will attach photos. Carb looks to be open quite abit. I pumped the throttle twice and the butterfly seems to have closed 50%. It did not move by just turning key to "on position.

The boat started up right away. I had the throttle pulled out and advanced throttle up to the first click. Idle was about 725-750. Let it warm up 5 minutes. Pictures show temp of 135 which is my typical running temp. When i pulled the throttle back and popped it back in, idle stayed exactly the same rpm- no drop.

Do i need to adjust idle higher. Im thinking it wont die on me because its running on hose with less back pressure and no water resistance. What is the typical rpm idle when unloaded on a hose? I know to set it correctly i should be in the water. Does my flame arrestor look dirty?

Thanks for your help. What is the next step? Where do i look for the loose electrical plug connector, at rear of motor- lots of wires....

 

[1995SeaRay195]

[No message]

 

[1995SeaRay195]

Next step?