mercury 150 stalls at idle only during the hottest part of the day

[odom]

Engine starts and runs great but during the hottest part of the day it wonts to stall at idle after shut off for a while fishing. If I rev it for a 30/60 seconds then it runs fine. Otherwise, engine is performing perfect. New Thermastats, engine never reads above 150 degrees, good water pressure (Impella good).

Any suggestions?

Thank you

 

[Faztbullet]

Re: mercury 150 stalls at idle only during the hottest part of the day

What year engine as the earlier oval style fuel pumps are known for vapor lock.

 

[CDI Tech Support]

Re: mercury 150 stalls at idle only during the hottest part of the day

If all mechanical issues have been ruled out:

Disconnect the idle stabilizer (advance module) and reset the timing between 23-25 degrees Wide Open Throttle. If the problem clears, discard the idle stabilizer as it is not needed.

The Idle Stabilizer was a poor design. No benefit comes from it. When it fails, it can cause problems. It's not needed.

The Idle Stabilizer has three wires:

1. Black
2. White/Black
3. Red/White

The White/Black is connected to White/Black on one switch box.

 

[odom]

Re: mercury 150 stalls at idle only during the hottest part of the day

year 1998 ....

 

[odom]

Re: mercury 150 stalls at idle only during the hottest part of the day

Is there a fuel pump replacement option for my 1998 150 Mercury that could eliminate vapor lock?

Thank you for taking the time to help me.

 

[Faztbullet]

Re: mercury 150 stalls at idle only during the hottest part of the day

The square pump dont lock as much as the oval ones do, install a new diaphram kit with rivets and discard the rubber disc's.

 

[odom]

Re: mercury 150 stalls at idle only during the hottest part of the day

It appears that my diaphram is square....