Logo
FULL SITE MENU

2000 Mercruiser 5.7 MPI cold start flooding,, new engine

P

Paintblend

New member
I have a 2000 Mercruiser 5.7 new long block, new out drive , had injectors cleaned and tested, when i first start it cold it floods black smoke boils, i have to open throttle about 20% to keep it running and in a approximately 2 min it clears up and runs fine,,,,, after it gets heat in it it will start easily and run good,,, but cant get rid of cold start flooding,,,,, changed IAC and TPS no help,, what now,, new fuel pump with new engine,, pressure is 42 to 44 lbs when hit key then drops to around 20 and holds help

open for suggestions:rolleyes:
 
i did send the injectors and had them checked and cleaned,, how would i know or how could i check to see if they are leaking,, the pressure goes to approx 42 lbs when switch is turned on or the system is charged and then drops and holds on around 22 lbs,,, and as soon as the engine gets warmed up or gets some heat in it,, you can turn it off and let it set for a dew minutes and it will hit quickly and idle fine , over and over it is like something is telling it to flood at cold start up
 
Not likely that ALL of the injectors are leaking and causing overfueling. During warm-up phase the engine does run very rich until it reaches operating temp, the the ECU leans the mixture for normal operation. Not sure if that 40-odd psi is correct for this phase...maybe high? dunno but that might be part of it. Is there a faulty fuel pressure sensor or a vacuum leak on the pressure regulator? Just guessing here.
Never mess with TPS unless you know for a fact it's bad.
 
according to this particular model (2000) the MPI with throttle body the fuel pressure is correct ,, everything was new but i know things can be bad even new,, what has sent me for a loop is that as soon as it gets warmed up it runs great,,, before the new engine, i never had that problem ,, and i am tired of throwing money at it ,, it billows black smoke and sputters and spits ,, but just as soon as it warms and you clear it out it runs fine,,, i am going to replace the temp sensor on the thermostat housing today and see if that helps,,, (again throwing money) i'm in that no win situation i have spent more than the boat is probably worth and it still aint right , thanks for any suggestions
 
The bleeding has stopped,, all that was needed was an [h=1]805218T - Engine Temperature Sensor[/h]replaced this part and if fired up like a new motor,,, wait it is a new motor,,,, the sensor must have been giving an erroneous message to the ECM and was dumping the fuel in it ,, it now starts at the hit of the switch,,,,, LOVE IT
 
Back
Top