Mercury 150 ESI No Idle issues..

frustratedboater

frustratedboater

Chief Petty Officer
Joined
Jul 10, 2007
Messages
413
Model OGOO1967. I can't seem to isolate the extreamly rough idle. Here's the run down: replaced the poppet valve and checked thermostats. Water Fuel seperator replaced, and inline filter replaced..

In the carbed versions I'd go right to the low fuel circuit needles and clear the junk out, but with the fuel injection, I'm stumped as to where to go!

Is there a fuel pump that pushes the fuel in? Perhaps this is an electronic problem? I'd appreciate your views,

~fb~
 
C

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: Mercury 150 ESI No Idle issues..

Very good spark cranking or at idle as a broken trigger wire could drop a pair of cyls then reconnect and come back on as the wires are moved with throttle.

Check that fuel pressure remains constant, tho I doubt that fuel pressure would drop at idle, this is usually more a WOT problem.

Of course verify compression.

Injector tip cleanlyness, mineral accumulation on the nozzle(s) will affect spray pattern, a squirt gun will have low speed issues yet seem to run better at higher speeds.

Checking spray patterns is a PITA. You may end up sending the injectors out to Tony Brucato for cleaning.
 
frustratedboater

frustratedboater

Chief Petty Officer
Joined
Jul 10, 2007
Messages
413
Re: Mercury 150 ESI No Idle issues..

CharlieB,
Thanks for the tips regarding this motor. I'll have to track each possibility down and see what I find. Would there happen to be an idle stabilizer on that particular motor that I can check?

~FB~
 
Faztbullet

Faztbullet

Supreme Mariner
Joined
Mar 2, 2008
Messages
15,619
Re: Mercury 150 ESI No Idle issues..

Dirty injectors or MAP sensor in ECU...
 
frustratedboater

frustratedboater

Chief Petty Officer
Joined
Jul 10, 2007
Messages
413
Re: Mercury 150 ESI No Idle issues..

Forgive me, but where would I find, or what does the MAP look like on this engine?

~FB~
 
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