2000 Mercury 240 EFI M2 Sportjet Cold Start Stalling
Hi guys-I have been all over the forums looking for help with no luck. It seems like there are some great V6 techs on here so I'm hoping you guys can help. The problem: Upon initial trailer launch or after anchoring for 1 hr or more, I can easily start the engine. It runs momentarily but the slowly stalls and dies. It will immediately restart and repeat same stall. Solutions: Usually, I have to start it and quickly shift into forward and them throttle up to 50% or so and get underway. It hesitates, growls and then takes off. Once underway for a few minutes, I can bring it back down to idle no problem. Also runs great all the way up to WOT. It will continue to run great until shut off and sitting for 1 hr or more. Alternatively, I have found the d/c the port head temp sensor tan/blk leads will enrichen the engine enough to stay running after starting. However, it smokes like crazy and will load up at idle once warmed up. Rotating the TPS fully ccw yields the same results (no stalling, but too rich when warm).I have recently serviced the following with no success:-replaced fuel tank baffle-replaced water separator filter-replaced electric primer pump-rebuilt pulse pump-cleaned/inspected VST-replaced needle/float in VST-replaced high pressure VST pump w/used-removed injectors-had professionally cleaned/filters replaced, cleaned fuel rail & throttle body-replaced spark plugs-replaced port head temp sensor (also verified operation with cold water test)-tested air temp sensor (cold water test)-performed synchronization/timing procedure per manual-checked throttle body MAF sensor fittingI honestly don't know what to do anymore. I have spoken to mercury and they suggested a service bulletin to set idle timig at 10deg BTDC. I did and same results. Can anyone help me solve thus once and for all please??-verified fuel pressure @34psi when problem present
