MOSFET troubles

[quinnd]

I have a Denso ecu from a Mitsi 4D34T bus. Timing solenoid shorted and blew ecu driver and 0.5ohm series resistor.
I fitted new $500 solenoid 45 ohms, and this logic level mosfet to ecu RFP12N10L
Open circuit there is a 5V square wave signal to gate. With mosfet fitted the gate seems to pull this down to around 3.5V and as a result
I can't get the mosfet to full enhancement mode and get 3V drop across it producing heat.
Anyone have a good component part number that will work properly in this situation? Original was standalone, not on heatsink. And I am assuming it is a mosfet

[quinnd]

Maybe someone can identify this component?
Case marking is D70-9360231138231139

[Mr BLACK]

check link between gate and pwm driver must be a rezistor (5R- 47R ) see if is ok and what is frequency of gate signal ?

[quinnd]

check link between gate and pwm driver must be a rezistor (5R- 47R ) see if is ok and what is frequency of gate signal ?
Thanks, is driven via another transistor and 0.5k resistor to gate pin. BUT I have found a post on other site from 14 years ago, and he says he tested his and it was a normal NPN power transistor. Have found a NEC C4554 driver from denso ecu will work perfectly in this application. Simulated it on bench with 45 ohm inductive load, 5V base drive and gets around 0.16v drop across CE and minimal heat produced

[Mr BLACK]

is a darlington connection

[quinnd]

Here is datasheet for C4554 NPN epitaxial231353

[daniudada]

Any update on the D70-9360-k transistor? Any equivalent or replacement beside c4554?