Firebird V8-305 5.0L VIN F FI (1987)
Throttle Body: All Technical Service Bulletins
Throttle Body - High Idle/Stalling/Code 34 Set
Number 87-6(Gasoline)-30
Date 4/87
Subject:
THROTTLE BODY CARBON BUILDUP
1985-87 FIREBIRD MODELS EQUIPPED WITH 5.0L OR 5.7L PFI ENGINES (ENGINE CODES F AND 8)
Some 1985-87 Firebird vehicles may experience the following:
1.
Code 34 on restart.
2.
High idle speed.
3.
High accelerator pedal effort.
4.
Engine stalls at idle or during deceleration.
5.
Rough/low idles.
These conditions may be caused by carbon buildup inside the throttle body bores behind the throttle plates limiting air flow. It should be noted that what
appears to be just a small amount of accumulation can be enough to limit air flow.
To diagnose this condition, perform the following steps:
1.
Measure minimum idle speed using procedures defined in Section 6E3 of the Service Manual.
2.
If minimum idle speed is less than specified in chart, proceed to Step 3.. Otherwise, perform activities defined in the Service Manual under
Section 6E3, Section B - Rough, Unstable or Incorrect Idle, Stalling.
3.
Remove negative battery terminal.
4.
Remove mass airflow duct at throttle body.
5.
Cover TPS and IACV to protect from overspray.
THROTTLE BODY AIR INLET
6.
Stuff IACV air inlet passage with shop towel to prevent cleaner from entering passage (See Illustration).
7.
Block throttle lever in wide open throttle position.
8.
*Spray carburetor choke cleaner around throttle bore (s) and on back side of throttle valve(s). Avoid spraying directly at throttle shaft bearing
surfaces to prevent washing out factory lubrication.
*NOTICE:
THE CHEMICALS USED IN CARBURETOR CHOKE CLEANERS ARE VERY
STRONG. DIRECT CONTACT WITH ANY RUBBER OR PLASTIC PARTS WILL CAUSE SWELLING, CRACKING, OR
OTHER DAMAGE. DO NOT USE ANY CLEANER THAT CONTAINS METHYL ETHYL KETONE, WHICH IS AN
EXTREMELY STRONG SOLVENT, AND NOT NECESSARY FOR REMOVAL OF THIS TYPE OF DEPOSIT.