Understanding the fuel system for beginner?
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Understanding the fuel system for beginner?
Heya all.
So I finally got spark going, and have been reading up a lil bit on the fuel system (pump is currently hard wired), so I just wanted to make sure I have everything in check for my limited troubleshooting time tomorrow.
First off, it's an '88 NA. From what I gather, two things will activate the circuit opening relay - They key turned to start position, and the AFM while the engine is running. Now my relay works, using the jumper on the check connector, which closes the ground through the AFM circuit? So, is there a way to check the AFM with a multimeter or something?
Just want to make sure there isn't something dinky I'm overlooking. Thanks.
So I finally got spark going, and have been reading up a lil bit on the fuel system (pump is currently hard wired), so I just wanted to make sure I have everything in check for my limited troubleshooting time tomorrow.
First off, it's an '88 NA. From what I gather, two things will activate the circuit opening relay - They key turned to start position, and the AFM while the engine is running. Now my relay works, using the jumper on the check connector, which closes the ground through the AFM circuit? So, is there a way to check the AFM with a multimeter or something?
Just want to make sure there isn't something dinky I'm overlooking. Thanks.
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If you want to know if the internal fuel switch works inside the AFM then w/key to on measure the Brown wire in the Circuit Opening Relay and it should have 12 volts. If you then open up the AFM flapper the 12 volts will turn to a ground signal (low voltage as compared to 12 volts). And make sure you don't have the jumper at the fuel check connector in place for that would make both readings of the Brown the same which would be low voltage w/key to on.
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Hokay, finally got around to this car again after some difficulties with my other engine swap. Testing the AFM, flapper open or closed it's giving 12V, no completing the ground for the opening relay. Is there a way to clean this sucker, or is it a buy a new one type of thing?
I don't want to start taking it apart and find out I damaged something that could have been repaired.
I don't want to start taking it apart and find out I damaged something that could have been repaired.
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the AFM just has a little set of contacts that the flapper door pushes open when the flapper is closed. so when the flapper is closed, it should show and open circuit on a voltmeter, and if you move the door of the AFM, resistance should be almost zero.
the AFM doesn't turn on the circuit opening relay, it just is there so the pump can't run if the AFM is closed.
the two things that trigger the relay are the "start" on the ignition, and the ECU after the car is running
the AFM doesn't turn on the circuit opening relay, it just is there so the pump can't run if the AFM is closed.
the two things that trigger the relay are the "start" on the ignition, and the ECU after the car is running
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Okay, so I got some new fuel and she starts properly, but then dies as soon as she's done cranking if I don't turn on the fuel pump. And then she dies as soon as I touch the throttle.
The MAF's resistance doesn't change, stays in the 120K ohm range, so I'm going to tear it out and see what I can find.
The MAF's resistance doesn't change, stays in the 120K ohm range, so I'm going to tear it out and see what I can find.
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