454 Mag MPI Warm/Hot start issue

[alldodge]

Start Ignition volts 11.1
No start Ignition volts 10.4

Your loosing power

 

[JW in Texas]

Start Ignition volts 11.1
No start Ignition volts 10.4

Your loosing power

Agree. Do you think try a starter next. Cables & connections are all solid.

 

[alldodge]

The ECM is measuring voltage from smaller wires feeding it. Don't think its the starter because like all electrical items, it either works or does not. While it could start turning slower, you have not mentioned that, as I remember

Its cables, connectors, switches. relays, wires

Would also add, if its only getting 175 rpm, then maybe a starter

 

[JW in Texas]

Wanted to finally put this one to bed since you guys were a big help. It ended up being a 15 dollar temp sensor. It literally took me longer to uncover the boat & get my tools then it did to replace it. Multiple mechanics with the previous owner & after I bought it couldn't solve this one. It showed in spec on the MEFI burn & "supposedly" was metered by the dealer when cold & hot. Anyway, it appears the sender was telling the ECU the boat was cold & flooding the plugs. Thanks again gang & happy boating.