3rd Gen / L98 Engine Tech 1982 - 1992 Engine Related

Idle starts at 1k, slowly rises to 1.5k

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Old 01-09-2004, 07:08 PM
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Idle starts at 1k, slowly rises to 1.5k

Ok so the car is an 84 camaro RS with a 305tpi in it. Upon starting it jumps to 1k rpm, then slowly rises to 1500. Revving it doesnt change the idle. I'll update when i find out more information on this, its a friends car. Thanks
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Old 01-09-2004, 09:41 PM
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Could the IAC be dirty and stuck open? Clean the TB and IAC and then reset the IAC and TPS and see what happens.
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Old 01-09-2004, 09:43 PM
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How do you reset the IAC and TPS?
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Old 01-09-2004, 10:22 PM
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Here is one way.

I set it with a scanner. I monitor the IAC counts on the scanner and try to get between 20-30 counts and then I adjust the TPS to the correct voltage.
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Old 01-10-2004, 01:00 AM
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Idle

This is from my Alldata for 85 - 88' 305/5.0L & 350/5.7L, couldn't find an 84 305TPI listed in the spec table, this is for Fuel injected models only.

Idle speed is speed controlled by the ECM through the Idle Speed Control motor and is not adjustable. The minimum air rate is adjustable as follows.

Best results obtained when TB is clean.
  • Ground diagnostic terminal, turn ignition on, but do not start engine.
  • Wait 45 seconds for IAC to fully seat, then with ignition still on disconnect IAC connector.
  • Disconnect the distributor set timing connector.
  • Start engine and allow engine to go into "Closed Loop". (When Temp gauge stablizes if you don't have a scanner. I'm not sure, but I think the SES flashing light will increase, or decrease in frequency when the engine goes into closed loop because the diagnostic terminal is grounded.)
  • Remove ground from diagnostic terminal.
  • Adjust idle speed to specifications using throttle stop screw. (500 rpm in drive for 305 TPI.)
  • Turn ignition off and reconnect IAC connector.
  • Adjust TPS voltage if necessary: With ignition "ON/Engine OFF" use a scan tool or 3 jumper wires to adjust TPS sensor to correct voltage specification. Tighten screws, then recheck reading to insure adjustment has not changed.
  • Start engine and check for proper idle operation.
Don't forget to reconnect the "Distributor Set Timing Connector"

Try to achieve the highest voltage reading at WOT (minumum of 4.50v) without losing the idle voltage setting (0.45v ±0.04v,) and watch the voltage reading as you slowly open the throttle, any sudden, and large voltage jumps are symptoms of a bad TPS. A bad TPS could the problem.



Please post results so that others can learn from your experience.
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