hi - 1993 del sol with 1.5 engine - I have replaced all ignition components, including the ECM - does anyone know if the TPS or MAP sensor could be part of my problem? Also, when the engine is cranking, the tach doesn't move - does this mean anything? thanks

 

Ground wires OK? Check for 5 volts at the sensors and 12 volts at the distributor. I think if the sensor power is shorted out, the whole ECU will shut down. But bad readings from the MAP or TPS will not inhibit sparking. Does the CEL cycle on and off when the ECU boots up (turn key on but don't start)? Are any codes set?

 

Hello again - the grounds are clean and I'm getting 5V+ at the sensors. The CEL is always on - it never cycles on + off. Also, I'm not getting any codes - I was told that no code is equal to a " 0 " code, which points back to the PCM ( ECU ?) What are your thoughts? I'm certainly confused !

 

CEL always on with key on but don't start (assuming the test jumper is not installed) is typically the main relay, could also be a bad ECU or lacking one of the power and ground supplies to the ECU. Did you check the small ground wires on the thermostat housing? The ECU and sensor system grounds there.

In other words:
Test jumper out -- CEL cycles on and off with key on before starting. Will light steady after starting if a trouble condition is detected.
Test jumper in -- CEL will blink out any codes while ignition on whether engine is running or not. Will light steady if there are no codes. Also spark timing feedback loop disabled so mechanical timing can be adjusted.

 

Hello again - without the jumper, the cel is a steady on with key in the "on " position -
Unfortunately, when I jump the connector, the cel is a steady on as well - I guess my next step will be to check the power and ground supply to the ECM - thanks