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Discussion Starter #1
my car started acting up at my work's parking lot. starts but then it dies out. i know its not the idle bypass valve cause it starts and even if i accelerate it or put a piece of hose on the throttle stop, acts as if would cut the fuel off. i'll rev it @ 2000 rpm steady and even if i dont move the throttle it still dies. i had to leave it at work (30mi away) any help greatly appreciated
 

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fuel filter
 

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then why don't you list everything you've done to the car recently as well as what you've checked (you have checked things so far, right?) to avoid this merry-go-round??

for what it's worth, i got $5 on a huge vacuum leak
 

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oooooooo ok I'm outta here....

then why don't you list everything you've done to the car recently as well as what you've checked (you have checked things so far, right?) to avoid this merry-go-round??

for what it's worth, i got $5 on a huge vacuum leak
That is a good guess. Does it rev on it's own then die?
 

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He'll chime in with more stuff.

But can you imagine if our forecast was that.
 

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Discussion Starter #9
so far i checked:
spark plug wires
coil connections
for loose wires
bypass valve
fuses
i couldnt get under the car to check wiring down there
im going to check the cpu for codes but check engine light is not even on(bulb is good)
 

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Battery, alternator, bad gas, no gas (fuel pump)? I bet it's the IAC.

Clean the MAF!
 

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Discussion Starter #12
today i check engine light came on after more attemps to start it. i got a P0102 code which is the Mass Air Flow (MAF) Circuit Low Input

is this a dirty sensor?:confused:
 

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:zwthstpd:

Did you try this yet?
:zwthstpd: me too... But Chris, wouldn't a bad MAF only show up in closed-loop, not when cold in open-loop? :zdunno:
 

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open-loop doesnt mean that the maf isn't used....it means that the loop that the PCM uses for air:fuel tuning is "broken up" by not using the O2s as a means of feedback on the maf......when in open-loop, all it means is that fueling is based off of whatever lambda is commanded the Base_Fuel_Table, and not gasoline's stoichiometric ratio of 14.67:1
 

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open-loop doesnt mean that the maf isn't used....it means that the loop that the PCM uses for air:fuel tuning is "broken up" by not using the O2s as a means of feedback on the maf......when in open-loop, all it means is that fueling is based off of whatever lambda is commanded the Base_Fuel_Table, and not gasoline's stoichiometric ratio of 14.67:1
Ok, I misunderstood. I thought open-loop used ONLY that Base_Fuel_Table and not the other inputs, such as MAF. I remember when my MAF went bad, it would only show up when the car was hot, it always ran good cold; that's the only experience I was going by...

Regardless, did the OP try unplugging it?
 

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Ok, I misunderstood. I thought open-loop used ONLY that Base_Fuel_Table and not the other inputs, such as MAF.
you're right...it ONLY uses the Base_Fuel_Table, but you just gotta remember that this fuel table is not a table of injector pulsewidths vs RPM for the computer to command...it is a table of air:fuel ratios (in terms of lambda), so it still needs to know actual ingested airfllow to compute fuel delivery requirements, therefore the maf is inextricably mixed with the Base_Fuel_table

i doubt he has followed some of the advice here...lol....everyone wants everything solved by gedankenexperiment lol
 

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you're right...it ONLY uses the Base_Fuel_Table, but you just gotta remember that this fuel table is not a table of injector pulsewidths vs RPM for the computer to command...it is a table of air:fuel ratios (in terms of lambda), so it still needs to know actual ingested airfllow to compute fuel delivery requirements, therefore the maf is inextricably mixed with the Base_Fuel_table

i doubt he has followed some of the advice here...lol....everyone wants everything solved by gedankenexperiment lol
Gotcha on the EEC, but I don't get the gedankenexperiment :zdunno:
 
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