Bad Idle Surge on '88 Fox w/Mods

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dangrego

New Member

Jun 14, 2006

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Sep 12, 2009

#21

• Sep 12, 2009

• #21

wow, actually got the KOER codes this time:

Results:

21 R: Cooling Temperature sensor out of specified range or ECT out of range

94 R: Air diverter solenoid circuit fault

44 R: Thermactor air system fault

...is the thermactor air system fault for the smog controls? if so, i gutted all that **** with the A/C too. ???

There it is finally, KOER results!!

 

liljoe07

5 Year Member

Feb 18, 2009

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Cartersville,Ga

Sep 12, 2009

#22

• Sep 12, 2009

• #22

Was the car up to operating temp, if not Code 21 will show. So the test needs to be done its good and warm. If code 21 comes back even with the car warmm replace the ECT sensor

 

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dangrego

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Jun 14, 2006

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Sep 12, 2009

#23

• Sep 12, 2009

• #23

car was borderline warm...will redo it right now to rule things out...how long u going to be online tonight- and thanks for the help with this. what do you think of the other codes? v/r dan

 

liljoe07

5 Year Member

Feb 18, 2009

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Cartersville,Ga

Sep 12, 2009

#24

• Sep 12, 2009

• #24

The other codes are SMOG related codes. I should be on for a while

 

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dangrego

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Jun 14, 2006

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Sep 12, 2009

#25

• Sep 12, 2009

• #25

well, i redid the KOER test with a fully heated up car....still got the 21. see attached pic of how the ECT sensor is rigged up.

 

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• 88 stang help 001.webp

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dangrego

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Jun 14, 2006

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Sep 12, 2009

#26

• Sep 12, 2009

• #26

by the way, do you know where the idle air bleed screw would be by any chance?

 

liljoe07

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Feb 18, 2009

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Cartersville,Ga

Sep 12, 2009

#27

• Sep 12, 2009

• #27

How new is the sensor?

And does that hose run to the heater core?

Also what intake is that?

 

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dangrego

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Jun 14, 2006

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Sep 12, 2009

#28

• Sep 12, 2009

• #28

sensor is a year old and yes, it does run to the heater core (a vintage "under-dash" heater, not stock). Edelbrock RPM Performer II upper and lower intake.

 

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dangrego

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Jun 14, 2006

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Sep 12, 2009

#29

• Sep 12, 2009

• #29

also, just on my mind just now is that when i test the fuel pressure, i get the same reading whether or not the vacuum hose is on or off the fuel pressure regulator. is that normal? i have 24 lb injectors running at stock 39 psi fuel pressure.

 

liljoe07

5 Year Member

Feb 18, 2009

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Cartersville,Ga

Sep 12, 2009

#30

• Sep 12, 2009

• #30

Once vacuum is removed from the FPR, the PSI should go up about 5-6 PSI.


Is there not a spot on the back of the lower intake you could route the ECT sensor too? My Heater Core setup is just like yours(rubber hoses), but I put the ECT sensor in the back on My Cobra intake.

I dont see why it wouldnt work the way you have now. usually if there was an open in the ECT wiring it would throw a code 51, which a ECT circuit open code. So im inclined to think the wiring is fine as is.

 

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dangrego

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Jun 14, 2006

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Sep 12, 2009

#31

• Sep 12, 2009

• #31

wow, i am dumb, you can't have vacuum with the engine off, so now i did my fuel pressure with the engine running and low and behold, makes about a 6 psi delta when you put on or take off the vacuum line. so now the fuel pressure is for sure set right, but car is still having problems. sorry about the blunder!!

 

liljoe07

5 Year Member

Feb 18, 2009

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Cartersville,Ga

Sep 12, 2009

#32

• Sep 12, 2009

• #32

Check the voltage at the ECT sensor. Unplug the ECT sensor, and hook a voltmeter to the two wires. Key on should have 5v. If that checks out, just replace the sensor.

 

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dangrego

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Jun 14, 2006

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Sep 12, 2009

#33

• Sep 12, 2009

• #33

rog, will give it a shot.

 

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dangrego

New Member

Jun 14, 2006

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Sep 12, 2009

#34

• Sep 12, 2009

• #34

got 4.55 koeo

 

BK_CAULEY

it's built for speed not longevity, woman

Dec 26, 2006

0

10

49

Thomasville, ga

Sep 12, 2009

#35

• Sep 12, 2009

• #35

liljoe07 said:

If that checks out, just replace the sensor.

Click to expand...

wow this sounds familiar

 

liljoe07

5 Year Member

Feb 18, 2009

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Cartersville,Ga

Sep 12, 2009

#36

• Sep 12, 2009

• #36

BK_CAULEY said:

wow this sounds familiar

Click to expand...

Could have been many things causing his problem. Im not one to suggest parts without going through proper procedure.

Just throwing parts at something gets costly.

 

liljoe07

5 Year Member

Feb 18, 2009

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Cartersville,Ga

Sep 12, 2009

#37

• Sep 12, 2009

• #37

dangrego said:

got 4.55 koeo

Click to expand...

You may need to re think your ECT sensor loaction if a new sensor doesnt work.

 

BK_CAULEY

it's built for speed not longevity, woman

Dec 26, 2006

0

10

49

Thomasville, ga

Sep 12, 2009

#38

• Sep 12, 2009

• #38

dangrego said:

by the way, do you know where the idle air bleed screw would be by any chance?

Click to expand...

it is under the throttle body. hold on i will get you a pic.

 

BK_CAULEY

it's built for speed not longevity, woman

Dec 26, 2006

0

10

49

Thomasville, ga

Sep 12, 2009

#39

• Sep 12, 2009

• #39

liljoe07 said:

Could have been many things causing his problem. Im not one to suggest parts without going through proper procedure.

Just throwing parts at something gets costly.

Click to expand...

yes it does. fast too.

 

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dangrego

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Jun 14, 2006

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Sep 12, 2009

#40

• Sep 12, 2009

• #40

cool, thanks. remember, my ECT is no longer on the heater rail...it is in line with my modified heater hose stuff to get heat in the car with a vintage heater. v/r