Testing AFM 10th AE and Air Bypass question
HAILERS
Joined: May 2001
Posts: 20,563
Likes: 27
From: FORT WORTH, TEXAS,USA
(((((Oh and one more thing, how do i test the module under the dash next to the steering colomn?)))))))))))))))))0
Jumper the fuel pump check connector that is located near the boost/pressure sensor. It's yellow in color and is a two socket connector. Usually has a piece of black shrink tubing around it.
Then turn the key to ON. The pump will run. Listen to the pump at the tank to confirm it's running.
When you jumper the fuel pump check connector, and the fuel pump runs when the key is put to ON, then you proved the circuit opening relay near the steering wheel is good.
If the pump runs as described above, and the engine will only run for ten seconds WITH the fuel pump check connector jumpered, then it's not a fuel pump problem in my humble opinion.
OR, pull the air filter out of the airbox. Turn the key to ON. Push the vane in the afm aft. Even a quater inch aft shouild do the job. Listen as you do that. The fuel pump should run if you do that. When you shove aft on the vane, that act put a ground on the circuit opening relay which in turn pulls the relay in and puts power to the fuel pump.
Engines that only run for a few seconds and then die, are engines that have a very large air leak. What happens is that during the Start cycle a large amount of fuel is injected, but once the engine starts, the Start fuel map is no longer available and now the AFM determines how much fuel is needed. The afm isn't signaling the ECU to inject enough fuel because the afm is ignorant about the large air leak on the downside of the afm. Fix the large air leak.
Jumper the fuel pump check connector that is located near the boost/pressure sensor. It's yellow in color and is a two socket connector. Usually has a piece of black shrink tubing around it.
Then turn the key to ON. The pump will run. Listen to the pump at the tank to confirm it's running.
When you jumper the fuel pump check connector, and the fuel pump runs when the key is put to ON, then you proved the circuit opening relay near the steering wheel is good.
If the pump runs as described above, and the engine will only run for ten seconds WITH the fuel pump check connector jumpered, then it's not a fuel pump problem in my humble opinion.
OR, pull the air filter out of the airbox. Turn the key to ON. Push the vane in the afm aft. Even a quater inch aft shouild do the job. Listen as you do that. The fuel pump should run if you do that. When you shove aft on the vane, that act put a ground on the circuit opening relay which in turn pulls the relay in and puts power to the fuel pump.
Engines that only run for a few seconds and then die, are engines that have a very large air leak. What happens is that during the Start cycle a large amount of fuel is injected, but once the engine starts, the Start fuel map is no longer available and now the AFM determines how much fuel is needed. The afm isn't signaling the ECU to inject enough fuel because the afm is ignorant about the large air leak on the downside of the afm. Fix the large air leak.
Originally Posted by NZConvertible
Untrue. That relay doesn't switch the pump on and off, it simply switches the resistor in and out of parallel, and it's wired to be fail-safe. If it fails the fuel pump will get full voltage all the time rather than reduced voltage at low load.
The relay (on the left) controls the resistor (on the right). They control the voltage sent to the pump and hence it's speed. as I described above. This will not be causing your problem. The circuit opening relay under the dash is what turns the pump on and off. Like I said, see page 50-34 of the FSM wiring diagrams.
Corrrect.
The relay (on the left) controls the resistor (on the right). They control the voltage sent to the pump and hence it's speed. as I described above. This will not be causing your problem. The circuit opening relay under the dash is what turns the pump on and off. Like I said, see page 50-34 of the FSM wiring diagrams.
Corrrect.
Try unplugging it and see if the car runs. Mine went bad on my car. I replaced it and no more problems. That was the only change.
Thread Starter
Senior Member
Joined: Oct 2006
Posts: 467
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From: Reno
Ok, so i jumpered the fuel pump connector, and the car did the same thing. The only difference this time is that it may have flooded. SO, I guess its not the fuel pump messing up. Now the car wont start, so Im almost positive its flooded now. I think it must have to do with the leak near the TB. Im having a hell of a time locating where its coming from though. I know that it is on the rear of the engine, on or near the throttle body. I used my boost leak tester on it, and can hear the leak, but i cannot see it. What should i test next? I was gonna try to press on the AFM flapper to see if it turns on the pump, even though it should because its in spec according to the FSM. Do you know what might be leaking on the backside (firewall side) of the TB? Is there a clear pic floating around of all the connections on the backside? Thanks again guys, i know this is kind of a pain, but i really need this thing running soon.
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