350 mpi horizon no start

[ericv26]

hey guys. I just aquired a 260 aft cabin wellcraft on an aluminum trailer for 500 bucks. while the boat is a pos,the engine and bravo 2 outdrive were installed about 5 years ago new and only used a few times befor boat went into storage. My intentions are to part out this boat and use the money to finish my 75 stamas. I have managed to get the engine to turn over and I have fuel pressure but it is a no start . I know the fuel sucks but I also dont have spark. the temp guage is reading 240 . will this kill the spark? I only want to get it running to show potential buyers. the engine and drive look like new. any help would be great

 

[alldodge]

Re: 350 mpi horizon no start

The MPI has several sensors which the gauge showing overheat should not cause an issue, the other temp switch could. Could use an engine serial number preferred, but at least a year for the engine.

Do you hear the fuel pump turn on before you start to crank?
(I'm guessing you do since you have pressure)

You say you have fuel pressure, how much?

Are you getting 12 volts at the coil?

 

[ericv26]

Re: 350 mpi horizon no start

not sure how much pressure. push fuel schreader valve and fuel sprays. where do I find serial number on merc? thanks for reply

 

[alldodge]

Re: 350 mpi horizon no start

not sure how much pressure. push fuel schreader valve and fuel sprays. where do I find serial number on merc? thanks for reply

Serial number if not on the top of the air intake plenum. then check the valve covers, and above the starter on a plate.

Give us a year of the boat which can help

Do you hear the fuel pump run when the key is turned to on?

 

[ericv26]

Re: 350 mpi horizon no start

near as I can tell boat is mid 80's. I know from previous owner that engine and out drive were replaced 4 to 5 years ago at a cost above 15k. fuel pump runs for about 10 sec after key is turned on which I fig is about normal till engine fires. little backround on me. I am a Ford Senior Master Tech so I know my way around engines. I put a plug in plug wire and had kid crank and no spark. engine sounds strong. no low compression sounds .even with the bad fuel I think it would hick up or something. I have a ton of sbc experience,but all befor computers. been with ford since 94. thanks for help

 

[alldodge]

Re: 350 mpi horizon no start

Knowing the fuel pump kicks on is good, this tells me the main power relay and fuel pump relay is working. Knowing the engine was replaced 5 years ago with an MPI tells me this would be a complete Merc new build possibly. I'm going to put the engine model year at about 2007 for now until I hear something different. If so you may have a crank position sensor.

The fuel injection system is controlled by the ECM. The fuel relay comes on for 5-6 seconds before start. Once the key turns to start the ECM looks for pulses coming from the distributer/or crank position sensor before it will start to pulse the injectors. If no pulses are received the fuel injectors will not fire. Check to see if you have 12V on the + side of the coil before and when cranking.

Also check to see if your getting an RPM signal while cranking engine over.

 

[ericv26]

Re: 350 mpi horizon no start

thank you. will do that tonight when I get home from work. I am sure the engien is newer than 87 as I work with the previous owner and it was installed as a complete package around 4 to 5 years ago at a mercruiser dealer. I will also look for the serial number for the next post. again thank you

 

[ericv26]

Re: 350 mpi horizon no start

ok found tag on oil pan and I assume one of these is serial number mn9344031 or m307310041. also I brought home my noid lights and installed on injector harness and no flash. I have 3 wires going to coil. one red with white tracer and 2 green with white tracer. didnt want to start probing until I was sure which one was positive.I assume it is red/white. thanks

 

[alldodge]

Re: 350 mpi horizon no start

ok found tag on oil pan and I assume one of these is serial number mn9344031 or m307310041. also I brought home my noid lights and installed on injector harness and no flash. I have 3 wires going to coil. one red with white tracer and 2 green with white tracer. didnt want to start probing until I was sure which one was positive.I assume it is red/white. thanks

The wires should be Purple on the + side and gray on the - side. The wires your looking at appear to be coming from the distributer.

 

[ericv26]

Re: 350 mpi horizon no start

thisl is the plug directly plugged into the coil.the wire colors u state are the same as my carborated engine in my stamas. this is fuel injected engine

 

[alldodge]

Re: 350 mpi horizon no start

thisl is the plug directly plugged into the coil.the wire colors u state are the same as my carborated engine in my stamas. this is fuel injected engine

Looks like were having the issue with the year. They did make an MPI in 87 which used the standard coil. You engine could be a complete new engine with wiring harness and would use the newer style plug in. In that case if I use the 2001 and later MPI wiring diagrams it would be the Pink/White stripe would be the 12 volt to supply the coil

 

[ericv26]

Re: 350 mpi horizon no start

ok thanks. like I said I know for a fact that the engine and outdrive were replaced as a complete set 4 to 5 years ago with a new mercruiser set up. this cost the last owner big money. I just want it to run befor I sell it