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ea81t again.... general fuel injection q


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Would an aac valve sticking make a car run rich? Just throwin' out an idea here, see what others think... thanks!:)

 

No, Think of the aac as another throttle.

Any air passing through it is metered so no mixture change.

If it was stuck open,you would have a high warm idle.

If it was stuck closed,you would have crappy/no cold idle.

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Uhhh Some kind of air bleeder valve. that lets the car run rich when it's cold.

 

Nope,you missed the point.It doesn``t affect the mixture.

it just "opens the throttle" a little.

CTS and air temp. sensor will control mixture when cold.

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No no no, this device does nothing to the throttle, it's mounted above the t-stat on ea81t and ea82 mpfi intake manofolds... It's a valve thats normally closed when the car is cold and when it warms up, it lets more air into the intake or something like that. it's a fuel injection version of a choke. Only it works by letting more air in after the mass airflow sensor I think. So the computer always runs it on the rich side, and counts on that little bit of extra air to lean it out a bit once it's warm I think... Something like that.

 

 

 

Nope,you missed the point.It doesn``t affect the mixture.

it just "opens the throttle" a little.

CTS and air temp. sensor will control mixture when cold.

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Any clue where the cts and air temp sensors are?

 

 

 

No no no, this device does nothing to the throttle, it's mounted above the t-stat on ea81t and ea82 mpfi intake manofolds... It's a valve thats normally closed when the car is cold and when it warms up, it lets more air into the intake or something like that. it's a fuel injection version of a choke. Only it works by letting more air in after the mass airflow sensor I think. So the computer always runs it on the rich side, and counts on that little bit of extra air to lean it out a bit once it's warm I think... Something like that.
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No no no, this device does nothing to the throttle, it's mounted above the t-stat on ea81t and ea82 mpfi intake manofolds... It's a valve thats normally closed when the car is cold and when it warms up, it lets more air into the intake or something like that. it's a fuel injection version of a choke. Only it works by letting more air in after the mass airflow sensor I think. So the computer always runs it on the rich side, and counts on that little bit of extra air to lean it out a bit once it's warm I think... Something like that.

 

I wasn`t trying to suggest it actually moves the main throttle.

It is like a second throttle in paralell w/the main one.

It is the fuel injection version of a fast idle cam,not a choke.

All it does is bypass air around the main throttle.

The airflow meter doesn`t know if the air went through the aac or by the throttle plate.

The computer doesn`t "count on that little bit of extra air to lean it out a bit once it's warm".

Actually it is open when cold and closed when warm.

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Quote:

Originally Posted by Mr. Carb

Any clue where the cts and air temp sensors are?

 

 

If you mean the ambiant air temperature switch, it is on the spare tire support.

 

 

Air temp sensor for fuel injection is in the airflow meter.It is a variable resistor between terminals 1 and 5

of the airflow meter.(the outside ones)

20 degree C resistance is 2-3k.Lower at higher temps, higher at lower.

 

CTS is the electrical doodad w/2 wires below the AAV,directly behind the cooling fan near the disty vacuum advance.

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Ok, well, the aac valve did nothing diffrent when unpluged or plugged in, Grabed a spare one austin had lying around, wich did go click when I plugged it in, So, I changed them, the car seems to run a bit better now. I found the abiant temprature sensor, it's on the turbo sheild attached to the tire mount cross bar, right? Also, what does the cts thing... do? Sorry, I'm short termed memory here, and this is the first fuel injected car I've ever tackled. Thanks for the help and patiance with me.:)

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If you mean the ambiant air temperature switch, it is on the spare tire support.
Ok, well, the aac valve did nothing diffrent when unpluged or plugged in, Grabed a spare one austin had lying around, wich did go click when I plugged it in, So, I changed them, the car seems to run a bit better now. I found the abiant temprature sensor, it's on the turbo sheild attached to the tire mount cross bar, right? Also, what does the cts thing... do? Sorry, I'm short termed memory here, and this is the first fuel injected car I've ever tackled. Thanks for the help and patiance with me.:)

Boy, you weren't kidding about that short term memroy told you where the temperature sensor was only a post ago!

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Ok, well, the aac valve did nothing diffrent when unpluged or plugged in, Grabed a spare one austin had lying around, wich did go click when I plugged it in, So, I changed them, the car seems to run a bit better now. I found the abiant temprature sensor, it's on the turbo sheild attached to the tire mount cross bar, right? Also, what does the cts thing... do? Sorry, I'm short termed memory here, and this is the first fuel injected car I've ever tackled. Thanks for the help and patiance with me.:)

 

CTS is the coolant temperature sender.It tells the computer the engine temp. so it can adjust the mixture accordingly.

It is a variable resistor of about 2.5k ohms at 20 degrees C.,under 1k ohms at 50C.Look for corrosion at the connector too.

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CTS is the coolant temperature sender.It tells the computer the engine temp. so it can adjust the mixture accordingly.

It is a variable resistor of about 2.5k ohms at 20 degrees C.,under 1k ohms at 50C.Look for corrosion at the connector too.

Ok, thanks, I'll go check that out, It's Not the same sender as the sender that tells the dash gauge what to read is it?

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