oh god, please hlep... idle/ start problems

McDewbie

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May 11, 2012
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British columbia
It goes from aprox 2k to aprox 1800, but some times it goes slightly higher/lower. Also today to see if it might be an open loop problem I tried unplugging the air flow sensor at the air box and the engine just cut out
 
Oct 11, 2005
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Thousand Oaks, CA
You checked the timing with TE1 grounded?

You checked the ISCV is not stuck open (you hear it click after shutdown)?

If above are good, you checked the TPS? Unplug it and see if lope is impacted.


MK3Supra17;1840803 said:
The o2 sensor will see a lean condition (provided its in closed loop) and will signal for more on-time at the injectors resulting in a high idle.

Not to mention that the idle speed is controlled by the ECU, so the ISCV would be adjusted to maintain the target value.
 

McDewbie

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May 11, 2012
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British columbia
I dont understand how you check timing if the engine doesnt get to the desired rpm to time it? also no matter what i shove into the diagnosis box nothing ever seems to happen (have the same problem with my 88 pickup), is there some trick to doing it? and I had checked the ISCV and it did click, but as i think about it i dont remember it clicking the last time i started it, so il go check again later today. I have also bought a o2 sensor (was 10$, couldnt say no) to see if that does anything, thinking it might be sending the wrong numbers. I will also check the TPS today. and does anyone know how the iscv works?
 
Oct 11, 2005
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Thousand Oaks, CA
If TE1 is grounded, and the throttle is closed (based on IDL signal from TPS) and the car is not moving (speed=0) then timing will be set to 10 deg BTDC. Measure it with your timing gun, even though the idle is fast and lumpy it should hold at 10 BTDC if the above conditions are true.

The ISCV is a stepper motor. It is commanded full open at shutdown, and gets closed down after start to hit the target idle speed.
 
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AJ'S 88NA

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Jul 26, 2007
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In diag mode the MIL will show code 51 when the gas pedal is slightly pressed and no codes when released. If it does the TPS is set close enough. Never time the engine without first doing this test or at least checking for codes.

Can't remember were or from who I got this quote, I think from JJ.
 

McDewbie

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May 11, 2012
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British columbia
well i'd checked for codes and there are none so il do the gas pedal thing as well as check all the other stuff ive been saying i would ( schooling and work makes it hard to get around to my car)
 

McDewbie

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May 11, 2012
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British columbia
so i checked the iacv and it doesnt click... but i could swear it had before i tore it down for the 2nd time... anywho i gotta try to find one for less than 700$ see if it does anything, would it affect the difficulty to start