1999 Mercury EFI 150 hp ignition question ????

[flashmob]

1999 EFI 150 hp . Serial # OG843325 . Needing some advice on an inconsistent ignition problem with my motor . I have owned the motor for 14 years .It has been well taken care of and due to its age within the last year I have posted questions about issues I have had on BBC and have had awesome responses and I have the motor running as good as the day I got it or maybe even better . In the past year I have replaced all fuel lines, Mercury primer bulb and the mechanical fuel pump . New fuel filter . I just put a new complete water pump kit on it and today I put new high performance plug wires from Bobs machine shop on it . Plugs may be about 2 yrs old so I left them for now . My only issue that is left to work out is my ignition. There are certain times it will fire right up and other times it will start and die . I give it a second and it fires up most of the time on the second try . Does anyone have any idea what I need to do to improve this . I have a group 31 AGM Duracell battery for cranking . It’s been in the boat for 4 years. I’m pretty sure it isn’t a voltage issue because I can run live well and Electronics all day and not have a problem . I have never ran anything in my gas other than Stabil when I ran ethanol gas . After replacing all the fuel lines I have vowed to only use 93 grade non ethanol and I believe it has made a huge difference. I do a lot of idling looking for fish offshore on electronics and there always is a lot of carbon build up on inside of prop . I noticed when I replaced the water pump there was carbon on the drive shaft . I also saw that the guy that put the brand new lower unit on never put gasket sealer on the exhaust dam too so I made sure I did that . Is there anything else I can do to improve the turn of key start up ? I would do whatever I need to do to fix this . If anyone has any suggestions I would really appreciate it . I want to keep this thing running like new as long as I can .

[JOE54]

has anything been taken off mtr like oil inj or any modules ???

[flashmob]

No . The mtr is completely stock .

[EuropeanAM]

The fuel you are running is not helping. Unless your engine has been modified, it calls for 87 octane fuel.

Higher octane fuels burn slower and cooler- and on engines such as yours, they cannot burn completely which results in a rich condition.

Choose your fuels based on the correct criteria, IN THE CORRECT ORDER:

1. High-Traffic, Name-Brand, Top-Tier Fuel Station

2. CORRECT Octane for your engine (87).

3. Lowest Possible Ethanol Content available in the above (never to exceed 10%).

[flashmob]

Thanks for the info . I will not worry about using 93 now . But I had the same starting issue when I used 87 as well . Any idea what else I could try ?

[JOE54]

might advance idle timming just touch

[flashmob]

I have also noticed the motor is non responsive to accelerating until you depress the hotfoot on the second push of the pedal . I cannot figure out what I need to do to correct this .

[Merc2.4]

I have also noticed the motor is non responsive to accelerating until you depress the hotfoot on the second push of the pedal . I cannot figure out what I need to do to correct this .

What part tn you from?

[flashmob]

Johnson City TN .

[Merc2.4]

Johnson City TN .

10 4. Prob just few hrs from me. Now when u say depress throttle. So motor wont rev up until u left off throttle and hit it again?

[flashmob]

Yes. It eventually works itself out and runs ok .

[flashmob]

I put Chris Carson Marine Reeds in my motor and it corrected the problem . Amazing difference in over all performance . Starts up great and after I went through all hose connections with VST and I also put stuffer blocks on it too . Couldn’t be happier . Thanks for all that helped me !!!

[JOE54]