MEFI 3 diacom capabilities

[vroom ZOOM]

Hi, will diacom allow me to check for spark on a MEFI 3 motor?

The issue im chasing is no/intermittent spark while cranking. Its a late 90s 350 mpi with mefi3 and thunderbolt 5. The dizzy sensor is original but i'd like to check that the ecm is firing the coil alright before chucking parts at it. I'd like to just push a button on the software that fires the coil to check if that part is ok. Asking before I go buy the dongles for mefi.

Thanks

 

[tpenfield]

That would be a good question to ask the folks at Rinda (the company that makes Diacom) I assume you have the software? I know that some of the adapters are pricey, but the older ones (MEFI-3, etc.) are not too bad.

It's been a while since I used the Diacom on my MEFI-1 engines . . . Although, I'm not thinking that there is a 'test' on the software to fire the coil.

 

[dubs283]

Possible but not probable to test for spark with diagnostic equipment on a mercury mefi system. Capabilities are quite limited as the original DDT was used for onboard diagnostics when the engine was new

The ignition sensor is used for the mefi ecm to read engine rpm as well as control spark/timing. If no/intermittent signal is read spark will be affected

Best bet is to simply replace the ignition sensor in the distributor as it is most times the culprit for no/intermittent spark on thunderbolt and is a manitence/tune up item if still original. Use a new, OEM sensor and ground it properly

 

[Scott Danforth]

If you have the original 2-wire trigger in the TB-V, replace it with the 3-wire version.

 

[vroom ZOOM]

Engine sorted. Some smart fellow put iridium plugs with a washer seat on a motor with a thunderbolt ignition and taper seat plug holes. Also those plugs were super old. I was told they were changed recently, but after changing them anyways the motor lights up nicely.