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I only get noise in the air-box when i am jumping the relay.

I tried lifting the throttle with the (new & old) relay plugged in and I don't get noise from the engine bay and like I said no buzz from the fuel pump.
Old 03-08-2018, 07:35 AM
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Nope......

Quote:
Originally Posted by targa80 View Post
Again i ask is this with the relay in place?

If it is then it is normal, the noise from the frunk is the fuel pump motor. The noise in the engine compartment is the fuel flowing through the system. lifting the throttle plate closes the air flow switch and applies the ground to the fuel pump relay.


Targa80,

Your understanding of the wiring system for the AFS (airflow sensor) switch is flawed. You got it backward. Test terminal #85 (FP relay socket) using a TL (test light). One end of the TL from a 12-volt source (battery) and the probe to terminal #85. The TL should be LIT at this point (normal condition).

Now, raise the AFS (air flow sensor) and will cause safety switch to OPEN and the TL will turn OFF. When the air flow sensor plate is down, the switch should be CLOSED (grounded) not OPEN.

Tony
Old 03-08-2018, 08:46 AM
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Well you now know that the switch works since you close the switch when you lift the plate with the jumper across 87a and 30.

Voltage from the ignition switch when the key is in the start position passes from 87 and pin 30 to supply power to the fuel pump during the start phase. During starting air lifts the throttle plate and closes the air flow switch and provides power from the on ignition switch through contact 87a and 30 to the fuel pump.

Since your air flow switch is working you will need to find out why the relay does not energize and supply voltage to the air flow switch.

If it was my issue I would make up five test leads with an alligator clip and contact pin on each lead. I would then connect them between the relay and the connector so I could monitor the voltage on each lead using a multi-meter.
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Old 03-08-2018, 08:50 AM
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If I were to just swap out the plug socket harness with a new one. Would that not solve my issue?


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Old 03-08-2018, 08:52 AM
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REPEAT: nope......

Quote:
Originally Posted by targa80 View Post
Well you now know that the switch works since you close the switch when you lift the plate with the jumper across 87a and 30.

Voltage from the ignition switch when the key is in the start position passes from 87 and pin 30 to supply power to the fuel pump during the start phase. During starting air lifts the throttle plate and closes the air flow switch and provides power from the on ignition switch through contact 87a and 30 to the fuel pump.

Since your air flow switch is working you will need to find out why the relay does not energize and supply voltage to the air flow switch.

If it was my issue I would make up five test leads with an alligator clip and contact pin on each lead. I would then connect them between the relay and the connector so I could monitor the voltage on each lead using a multi-meter.

Pat,

Your understanding about how the AFS switch works is incorrect. You got it backward.

Tony
Old 03-08-2018, 08:56 AM
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Heck I'm only 5 not 66!
 
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Quote:
Originally Posted by boyt911sc View Post
Targa80,

Your understanding of the wiring system for the AFS (airflow sensor) switch is flawed. You got it backward. Test terminal #85 (FP relay socket) using a TL (test light). One end of the TL from a 12-volt source (battery) and the probe to terminal #85. The TL should be LIT at this point (normal condition).

Now, raise the AFS (air flow sensor) and will cause safety switch to OPEN and the TL will turn OFF. When the air flow sensor plate is down, the switch should be CLOSED (grounded) not OPEN.

Tony
Tony,

Ok, if you say so.

One question how do you supply the ground/return for the relay coil on the fuel pump relay when the relay is energized? Is it through the RPM limiter or through the alarm system if it is not through the closed contact of the air flow switch?

I was always under the belief that the air flow switch is normally open and only closes when air lifts the plate. This prevents the fuel pump from running when the ignition is on but the engine is not running.

Maybe my though process is totally wrong based on understanding of the schematics. If I am wrong then I apologize to all for the misleading information.
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Old 03-08-2018, 09:06 AM
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DKLever48ís post......

Quote:
Originally Posted by targa80 View Post
Tony,

Ok, if you say so.

One question how do you supply the ground/return for the relay coil on the fuel pump relay when the relay is energized? Is it through the RPM limiter or through the alarm system if it is not through the closed contact of the air flow switch?

I was always under the belief that the air flow switch is normally open and only closes when air lifts the plate. This prevents the fuel pump from running when the ignition is on but the engine is not running.

Maybe my though process is totally wrong based on understanding of the schematics. If I am wrong then I apologize to all for the misleading information.


Pat,

We all make mistakes and I make a lot too. Take a few minutes and browse DKLever48ís post about testing the FP relay and socket. That is where I direct people most of the time.

Tony
Old 03-08-2018, 10:23 AM
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All, just wanted to report back. With Tonyís instructions and help he figured out my coldstart valve plug were swapped around. Car fired right up after making the change. Very happy! Thanks everyone.


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Old 03-08-2018, 04:20 PM
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As in Post #9.

Glad its running.
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Old 03-08-2018, 07:21 PM
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