ECM/FUEL PUMP/PULSE GENERATORS

[rider1939]

'95 GL1500SE

I've read in several posts, under "NO SPARK", that the fuel pump doesn't/won't run nor will the tachometer register, if the pulse generators are not working.

Is this true, or is it just some years/models ? ? ?

Thanks

[DenverWinger]

On a 1500 90-2000 1500 If the PG is out, Tach won't register anything while cranking, won't be a spark, and fuel pump will only run while cranking starter. 88-89 models the fuel pump will run a second or two when ignition is first switched on, then stop.

[rider1939]

DenverWinger = = = Thanks for the info, much appreciated.

[rider1939]

About the Pulse Generators.

Should they be receiving any voltage, if they do, what is the expected voltage range ? ? ? Mine don't show any voltage.

[DenverWinger]

You shouldn't see any DC voltage on them.

They should read 400-500 ohms, and if you switch the meter to AC volts you should see them generate a very low AC voltage (way less than a volt, tiny AC pulses actually) when you crank the engine. It's these tiny pulses that the ECM uses to detect crankshaft position to control and properly time the spark. If the pulses are missing you have no spark.