Does the ignition Control module send any signal to the fuel pump?

[harpon]

Getting ready to get into this again- put in new fuel pump last summer and several new relays and the pump still didn;t come on. I ran a direct jump to the pump which whirred and whirred and pretty sure of polarity and still no start then. Before that my parked 91 would explode to life- So I'm still not getting the fuel pump fired through it's circuit and when jumped it still doesn;t start. WTF ???

someone said maybe the line isn't snug and pumping fuel around in the tank (when JUMPED only still, if that's it) Others say the relay gets a signal from the MAF ----most likely probably I guess, but is there any kind of signal from the ignition control module? Thinking of replacing anyway- and I wonder if I'll ever get this car on the ROAD? Anybody wanna buy an unrusted 91 with 75 K unofficially on the clock?

[FestYboy]

The ICM and fuel systems do not talk to each other at all. The VAF closes the circuit for the fuel pump relay. Since you can command the pump to run, can you verify fuel pressure and flow? The distributor tells the PCM to activate the injectors via the cam position sensor that's inside.

[Greywolf]

The pump will run for a few seconds when the key is turned on some cars, like the Suzuki swift. On a Festiva, if there is no airflow pulling the door of the Mass Airflow Sensor (MAF - it's the first item behind the air cleaner) open, the circuit isn't complete. You can test it by taking off the air cleaner and pushing the flap open with a screw driver.

To test for fuel pressure and/or leaks you'll need to do this so you can check the pump, and also the fuel pressure regulator.

NOTES:
The MAF is also called a "VANE AIRFLOW SENSOR" or VAF

ICM = Ignition Control Module

PCM = Powertrain Control Module

ECM = Engine Control Module and is similar to a PCM, except an ECM doesn't have anything to do with an electronic transmission. It's the basic computer that sits in the background measuring and controlling stuff...

You may have either an ECM or a PCM - whichever you have it's the same thing

~ I hope those few notes/definitions helped unscrew the otherwise inscrutable for you...

If you can get the fuel pump to run by pushing open the "VANE" in the MAF/VAF by doing that - it checks and verifies that everything is good from there on back. The idea was that if there is no airflow from a turning engine, there was no reason to run the fuel pump. An engine being turned over by it's starter motor would still pull enough airflow to crack open the sensor


For these cars one of the best tools you can own is a fuel pressure test set, they run about thirty bucks.