Airflow Sensor Door Flutters. Wtf?
05-28-09, 09:13 PM
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Airflow Sensor Door Flutters. Wtf?
i have an 88gxl
At idle my AfM door Opens then flutters then returns.. Is this what a bad AFM can do? Its like there is an electric motor opening the door and then stalling it out.
Anyone have this problem?
At idle my AfM door Opens then flutters then returns.. Is this what a bad AFM can do? Its like there is an electric motor opening the door and then stalling it out.
Anyone have this problem?
Last edited by rx7_FREAKKK; 05-28-09 at 09:17 PM.
05-28-09, 11:34 PM
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I lost all power while driving today. .. got it home and it idles then almost stalls and then picks up agian... plenty of power when i have it. but it keeps missing .. nothing like the tps issues.
Do afms go out slow and have problems before they stop working? or do they just not work,,
Mine smells like burnng resistors. never smelled that smell in a long time.
Do afms go out slow and have problems before they stop working? or do they just not work,,
Mine smells like burnng resistors. never smelled that smell in a long time.
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05-29-09, 12:35 AM
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wel my fuel sock for the fuel pump was very dirty. that got cleaned. Might see if anyone has a spare AFM i can borrow and see if thats the problem.. Other than that. maybe change the fuel filter... However its just way to eratic for it to be the fuel filter. But i guess i gotta keep chugin
05-29-09, 05:27 PM
#11
Take your AFM out and test the resistance values that the FSM lists. It can be hard to get a clear measurement sometimes, so give each a few tries.
You can also take a razor blade and cut around the black plastic cover on the top, pop it up, and inspect the small circuit board inside. If something is burning, it should be pretty obvious. Just don't mess with the gear or spring that are inside at all. That would affect the mixture under all conditions. When done, put some silicone sealer around the edge of the cover, and pop it back in place.
You can also take a razor blade and cut around the black plastic cover on the top, pop it up, and inspect the small circuit board inside. If something is burning, it should be pretty obvious. Just don't mess with the gear or spring that are inside at all. That would affect the mixture under all conditions. When done, put some silicone sealer around the edge of the cover, and pop it back in place.
05-30-09, 12:00 PM
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Not to cause a whole bunch of trouble...........but the series four AFM vane should not be moving/fluttering at all during idle. Non. Nadda. Zippity. Not visible to the naked eye type of non movement.
How do I know this? I was just now swapping two AFM on my car and I looked at 'em. Even had the plastic cover off 'em while looking.
I go with the answer wayyyy above that suggested a air leak problem OR a busted apex seal problem ORRRRRR someone has been messing with the spring in the AFM and got it ALLLL WROOOOOONG.
Just my take on this.
POST #6 indicates a blown apex seal. Do a cheap, by hand/finger compression check. Takes but ten to twenty minutes. THEN google MAZDATRIX for engine parts/cost. some humor there.
How do I know this? I was just now swapping two AFM on my car and I looked at 'em. Even had the plastic cover off 'em while looking.
I go with the answer wayyyy above that suggested a air leak problem OR a busted apex seal problem ORRRRRR someone has been messing with the spring in the AFM and got it ALLLL WROOOOOONG.
Just my take on this.
POST #6 indicates a blown apex seal. Do a cheap, by hand/finger compression check. Takes but ten to twenty minutes. THEN google MAZDATRIX for engine parts/cost. some humor there.
05-30-09, 03:06 PM
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mY door is visable to the naked Eye i took the stock air box off...
I can see it very good with the cone air filter off... What makes no sense is why the door flutters every 10 or so seconds... What i think is its starving for fuel and the Intake system tries to open the throttle for more air and fuel. That stops it from stalling..
So let me get this Right.. There is no electrical Assistance from the throttle control to the mass air sensor? That door follows the position of the throttle so perfectly its amazing.
Just move the throttle a milimeter and the door moves a milimeter with no change in idle..
I can see it very good with the cone air filter off... What makes no sense is why the door flutters every 10 or so seconds... What i think is its starving for fuel and the Intake system tries to open the throttle for more air and fuel. That stops it from stalling..
So let me get this Right.. There is no electrical Assistance from the throttle control to the mass air sensor? That door follows the position of the throttle so perfectly its amazing.
Just move the throttle a milimeter and the door moves a milimeter with no change in idle..
05-30-09, 03:55 PM
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OK, Well thanks... I think i found the issue (not 100% sure since i didnt place the new one on yet and ran it) .... Should have checked this filter first...
Well i took the fuel filter off.. When i was at the parts store i picked one up.
Now looking at this fuel filter thats on the car im sure this is the Original Fuel filter the car came with in 1988.
I am sure of it.. The fuel lines were on so hard they basicly grew to the fuel filter. Had to take the hose off peice by peice...
So that got me wondering after 30 minutes if trying to get that fuel filter off and draining it of gas (took over 5 minutes) I tried to blow into it.. And what a suprise It was like trying to blow into a um let me find the word, Stir stick from starbucks.. SO i blow into the new one.
And well its like blowing into a huge mcdonalds straw i could almost stay alive with the amount of air i was getting... I could not even empty my lungs with the old one blowng out before i needed air. SO
I am hoping this was the problem. Will be nice to have all my fuel pressure back.. Hope it wont blow my Pulsation dampener... Its been awhile since this thing saw normal fuel pressure...
Eeeeeek Bbl with the results
Well i took the fuel filter off.. When i was at the parts store i picked one up.
Now looking at this fuel filter thats on the car im sure this is the Original Fuel filter the car came with in 1988.
I am sure of it.. The fuel lines were on so hard they basicly grew to the fuel filter. Had to take the hose off peice by peice...
So that got me wondering after 30 minutes if trying to get that fuel filter off and draining it of gas (took over 5 minutes) I tried to blow into it.. And what a suprise It was like trying to blow into a um let me find the word, Stir stick from starbucks.. SO i blow into the new one.
And well its like blowing into a huge mcdonalds straw i could almost stay alive with the amount of air i was getting... I could not even empty my lungs with the old one blowng out before i needed air. SO
I am hoping this was the problem. Will be nice to have all my fuel pressure back.. Hope it wont blow my Pulsation dampener... Its been awhile since this thing saw normal fuel pressure...
Eeeeeek Bbl with the results
05-30-09, 07:00 PM
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If the engine is having a problem maintaining an idle of approx 750 rpm, then the BAC will open a bit more to get the idle up. When that happens, the vane on the afm will move/flutter a moment as the engine speed increases due to the BAC action.
On a series four car with no engine faults, the vane does not move at idle. Unless you move the throttle linkage ......or remove the BAC's electrical plug.....or pull a vaccum line off......or???? But at a normal idle, the vane does not move.
On a series four car with no engine faults, the vane does not move at idle. Unless you move the throttle linkage ......or remove the BAC's electrical plug.....or pull a vaccum line off......or???? But at a normal idle, the vane does not move.
05-31-09, 01:11 AM
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Well new fuel filter in.. Runs better for sure. Not having the problems i was having. Still wanted to do the stall out thing really fast once. But not like it was..
I think its possible the fuel pump got damaged Either from the switch i put on it, Or running fuel threw the old fuel filter so long. Because the wires going to the switch got pretty hot now that i think about it..
So i Removed the switch new fuel filter and clean sock.. To scared to take the car out since my driveway is so steep.. if the damn thing stalls out ill never get it back to the house. lol
I think its possible the fuel pump got damaged Either from the switch i put on it, Or running fuel threw the old fuel filter so long. Because the wires going to the switch got pretty hot now that i think about it..
So i Removed the switch new fuel filter and clean sock.. To scared to take the car out since my driveway is so steep.. if the damn thing stalls out ill never get it back to the house. lol
06-01-09, 11:03 PM
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Thanks dan... Since changing the AFM the problem has vanished, So far so good.
In all honesty i thought it was more of a long shot in the dark.
Not sure how afms go out or what happends when they do. But she's not bogging anymore.
In all honesty i thought it was more of a long shot in the dark.
Not sure how afms go out or what happends when they do. But she's not bogging anymore.
06-02-09, 01:18 AM
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