stalls at idle 1998 454

[btkatz]

Hi guys , need a little help. we got a 1998 merc inboard 454 mpi closed system in a sea ray that stalls under 1200 rpm. Under a load at higer rpms it runs fine but as soon as it warms up it stalls, ONLY AT IDLE! I have checked fuel pressure and it is in spec (35 lbs) never drops even during the stalling period. needed a new cap and rotor so we changed them as well as the plugs, also I swapped the ign module, map sensor,tps switch,and it still stalls .(we had a merc tech over and he thought it was the cap and rotor) tonight we are going to swap the coil and see what that will do. I don't believe it will help but what the heck I got the starboard engine as a parts store next to me. anybody had this problem?

 

[guyjg]

Re: stalls at idle

The IAC, Idle Air Control motor, is all gummed up.
[URL="http://www.mercruiserparts.com/Show_Pictures3.aspdnbr=82441898&ivar=images/CRUISER/824418.98/11.png&inbr=2690&bnbr=120&bdesc=INTAKE+MANIFOLD+AND+INTAKE+PLENUM"]http://www.mercruiserparts.com/Show_Pictures3.aspdnbr=82441898&ivar=images/CRUISER/824418.98/11.png&inbr=2690&bnbr=120&bdesc=INTAKE+MANIFOLD+AND+INTAKE+PLENUM[/URL]http://www.mercruiserparts.com/Show...r=120&bdesc=INTAKE+MANIFOLD+AND+INTAKE+PLENUM

 

[btkatz]

Re: stalls at idle

thanks guyig, but already tried that as well, swapped the coils and that didn't work either any other feed back on this would be great! running out of parts!

 

[guyjg]

Re: stalls at idle

How's the oil pressure? OP switch to fuel pump failing? Pump relay ok? Swap ECM's? Changed fuel filters lately? There is a filter in the pump--it may be partially clogged.