Hey everyone, I have a 2004 Searay 280 with twin 4.3 Mercruisers (MPI). Over the winter I swapped a motor out due to water intrusion and now after connecting everything I have a crank no start issue. I am currently trying to troubleshoot no spark going from the ignition control module to the distributor. I have verified the following:
I swapped fuel pump and main power relays between motors (they seem to be fine)
I have swapped the starter slave solenoid between the two motors (verified 12v on each post) I didn’t check the voltage for the 2 smaller posts but I believe those are for the starter and fuel pump ? Which both work
Swapped the sensor mounted to the front of the timing cover (both seem to work)
I swapped ECUs(whatever the engine controls module is called) both seemed to be working
Negative terminal connections on the bell housing studs look good
Fuses in the fuse bank look good
I get oil pressure readings on the gauges, so I think that would rule out no start due to oil pressure/oil pressure switch ( it’s my understanding oil pressure is a no start condition for TKS not MPI? Could be wrong)
I verified the shifter switches were working, won’t crank in forward or reverse so I think that’s good (unless there’s more switches I’m missing, only verified the ones on the shift plate mounted to the exhaust elbow)
There are no lanyards for the ignition so I don’t think I have that problem (just keys and they are both turned on)
All the batteries seem to be in good condition, I have a trickle charger on them so their always charged
There was no spark going to any of the spark plug wires, which lead me to no spark coming from the ignition control module. (Not thunderbolt, it’s whatever GM put out at the time P/N: 8M0054588)
I have verified there is 12v going to the ignition control module when the ignition is on
Could it be as simple as needing a new cap/rotor/distributor? The electrical connection on both distributors is missing so it seems mercruiser went away with that?
Pretty stumped on this, hoping to get some help, thanks in advance!
I swapped fuel pump and main power relays between motors (they seem to be fine)
I have swapped the starter slave solenoid between the two motors (verified 12v on each post) I didn’t check the voltage for the 2 smaller posts but I believe those are for the starter and fuel pump ? Which both work
Swapped the sensor mounted to the front of the timing cover (both seem to work)
I swapped ECUs(whatever the engine controls module is called) both seemed to be working
Negative terminal connections on the bell housing studs look good
Fuses in the fuse bank look good
I get oil pressure readings on the gauges, so I think that would rule out no start due to oil pressure/oil pressure switch ( it’s my understanding oil pressure is a no start condition for TKS not MPI? Could be wrong)
I verified the shifter switches were working, won’t crank in forward or reverse so I think that’s good (unless there’s more switches I’m missing, only verified the ones on the shift plate mounted to the exhaust elbow)
There are no lanyards for the ignition so I don’t think I have that problem (just keys and they are both turned on)
All the batteries seem to be in good condition, I have a trickle charger on them so their always charged
There was no spark going to any of the spark plug wires, which lead me to no spark coming from the ignition control module. (Not thunderbolt, it’s whatever GM put out at the time P/N: 8M0054588)
I have verified there is 12v going to the ignition control module when the ignition is on
Could it be as simple as needing a new cap/rotor/distributor? The electrical connection on both distributors is missing so it seems mercruiser went away with that?
Pretty stumped on this, hoping to get some help, thanks in advance!
