BoatnBrad

Need a little help here. I have a 350 mag mpi that has no spark/fire. The cap, rotor & wheel, and the sensor have been replaced. The coil and spark plugs have been replaced also. There is power into the coil and out to the distributor but nothing after that.

abmotorman

Sensor? Do you mean module or pickup?

BoatnBrad

Module. Sensor is the mercruiser parts term. I forgot to say that it has the Thunderbolt IV system according to my research. The pickup that you are referring to has to deal with a points distributor, correct?

SB

MPI with a Thunderbolt IV ? I would doubt it. Most MPI's have the external coil GM HEI distributor set up. Merc calls it the Voyager.

Here is the 'Voyager' , again, identical GM Late Model computer controlled external coil HEI
#8 is magnetic pickup
#9 is module
http://www.mercruiserparts.com/Show_...sp?dnbr=809488 97&ivar=images/CRUISER/809488.97/7.png&inbr=2333&bnbr=80&bdesc=DISTRIBUTOR+AND+IGNI TION+COMPONENTS

SB

Here is another tech tip of mine for anyone replacing an ignition module. Every ignition module I've seen (probably for 20 yrs anyway) in the car/boat/recreation world that is supposed to come with heat sink paste, comes with dielectric grease. Dielectric grease, because of it's properties is clear. Heat sink paste will typically be white. I've seen some copper color.

Dielectric grease does nothing for heat transfer, which the module needs. You can buy heat sink compound from Radio Shack or other electronic stores.
http://www.heatsink-guide.com/compound.htm

Buyer and installer beware !

BoatnBrad

SB the Voyager system information is great, but that is not what the boat has. I have found a service bulletin from Mercruiser No. 83-24 that has the distributor that the boat has. The only thing is that I have not found on the system is the Ignition Amplifier. Could the ignition be controlled by the ECM?

SB

What year is your motor ?

BoatnBrad

Oh boy. Here we go. Long story I will try to make it short. Boat is 2000 Regal 25LSC. Some where around 2001-2002 motor was replaced by a dealer no longer in business. I cannot find a Serial Plate and can't get to the the one by the starter to even see it, to find out what it is. The only place that I have found any kind of date is inside the distributor it has 12-20-99.

SB

Reason for asking is that most mpi/efi anything used the Voyager ignition system. The early models, like the 320EFI small block used the Tbolt IV.
If you haven't used an online look up, BAM's is nice:
http://www.mercruiserparts.com/SelectProductLine.asp

You can go thru all sorts of motors to find what youi have.

As a note, the modules and Compouters aren't usually listed under the 'Distributor and Ignition' page.

Somewtimes they'll be on the 'Exhaust' page or 'Intake Manifold' page.

BoatnBrad

SB thanks for the information I will take a look. This has been a nightmare. Everywhere I go that is the first thing everyone wants. (engine make & serial). Fortunately I haven't had to replace much on the motor but with age/use just getting the common maint. parts has been a chore. I normally remove the parts, go to a local dealer and try to match. That has been the norm lately.