5.7 RUNNING PERFECT WONT PASS EMISSIONS. NEED TO LEAN OUT A/F RATIO
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From: PHOENIX/ TOLLESON ARIZONA
Car: 90 IROC 5.7 1LE CLONE 89 GTA 88IROC
Engine: 5.7TPI / 5.7TPI/ 5.7TPI/ 4.3 CMFI
Transmission: 700R4 UPGRADED 700R4STOCK700R4STOCK
Axle/Gears: 3.23 10 BOLT 3.27 9 BOLT 2.77 9BOLT
5.7 RUNNING PERFECT WONT PASS EMISSIONS. NEED TO LEAN OUT A/F RATIO
WHATS THE BEST WAY TO SLIGHTLY LEAN OUT A 5.7 TPI WITH A MAP SYSTEM ? FALSE MAP OR MAT SIGNAL ? JUST NEED TO DROP HC BY .2 GRAMS PER MILE TO BE ELIGIBLE FOR A WAIVER. ENGINE IS RUNNING PERFECTLY NO SES LIGHT / COLD STARTS ARE GOOD. IDLE IS SMOOTH . THROTTLE RESPONSE IS EXCELLENT. ALL SENSORS WORKING. NEW IGN SYSTEM. STOCK CAM. I HATE LEANING OUT A PERFECT RUNNING ENG BUT THE STATE WONT PASS IT AFTER CLOSE TO $1000 IN REPAIRS.
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From: Chasing Electrons
Car: check
Engine: check
Transmission: check
Re: 5.7 RUNNING PERFECT WONT PASS EMISSIONS. NEED TO LEAN OUT A/F RATIO
Change the oil & filter and reduce the base timing a few degrees. Make sure that the secondary ignition parts are up to snuff.
RBob.
RBob.
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From: San Antonio TX
Car: 1990 G92 IROC Z Miniram
Engine: 388cu 6.4 Liters
Transmission: G-Force T5
Axle/Gears: 3.73 Gears
Re: 5.7 RUNNING PERFECT WONT PASS EMISSIONS. NEED TO LEAN OUT A/F RATIO
Set the timing to *6 degrees. Did you replace the cat(s)?
Thread Starter
Senior Member
Joined: Sep 2009
Posts: 598
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From: PHOENIX/ TOLLESON ARIZONA
Car: 90 IROC 5.7 1LE CLONE 89 GTA 88IROC
Engine: 5.7TPI / 5.7TPI/ 5.7TPI/ 4.3 CMFI
Transmission: 700R4 UPGRADED 700R4STOCK700R4STOCK
Axle/Gears: 3.23 10 BOLT 3.27 9 BOLT 2.77 9BOLT
Re: 5.7 RUNNING PERFECT WONT PASS EMISSIONS. NEED TO LEAN OUT A/F RATIO
THE CAT WONT HEAT UP. THE CAT IS 213 DEGREES F WHEN ENG IS FULLY WARMED UP. NO SES LIGHT. ENG RUNS PERFECT.
Thread Starter
Senior Member
Joined: Sep 2009
Posts: 598
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From: PHOENIX/ TOLLESON ARIZONA
Car: 90 IROC 5.7 1LE CLONE 89 GTA 88IROC
Engine: 5.7TPI / 5.7TPI/ 5.7TPI/ 4.3 CMFI
Transmission: 700R4 UPGRADED 700R4STOCK700R4STOCK
Axle/Gears: 3.23 10 BOLT 3.27 9 BOLT 2.77 9BOLT
Re: 5.7 RUNNING PERFECT WONT PASS EMISSIONS. NEED TO LEAN OUT A/F RATIO
REPLACED CAT WITH ONE FROM 1988 5.7TPI. FLOW CHECKED WITH SHOP VAC AND VISUAL INSPECTED. BYPASSED A.I.R. DIVERTER VALVE ( WORTHLESS) . ROUTED AIR PUMP OUTPUT STRAIGHT TO CAT. PASSED EMISSIONS NO PROBLEM.
ENG RAN PERFECT FOR A FEW MONTHS. NOW IAC TROUBLE....ANOTHER DAY ON THE ISLAND OF BROKEN DOWN CARS AND TRUCKS.
ENG RAN PERFECT FOR A FEW MONTHS. NOW IAC TROUBLE....ANOTHER DAY ON THE ISLAND OF BROKEN DOWN CARS AND TRUCKS.
Joined: Jun 2000
Posts: 5,364
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From: Enschede, Netherlands
Car: 82 TA 87 IZ L98 88 IZ LB9 88 IZ L98
Engine: 5.7TBI 5,7TPI 5.0TPI, 5,7TPI
Transmission: T5, 700R4, T5, 700R4
Axle/Gears: 3.08, 3.27, 3.45, 3.27
Re: 5.7 RUNNING PERFECT WONT PASS EMISSIONS. NEED TO LEAN OUT A/F RATIO
apart from fixing your car, fix your keyboard also... some pretzels must have gotten stuck under the caps lock button
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Joined: Mar 2008
Posts: 55
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From: jackson, new jerzy
Car: 87 iroc-z
Engine: LB9 305 tpi
Transmission: t5
Axle/Gears: 9bolt BW 3.45 (G92)
Re: 5.7 RUNNING PERFECT WONT PASS EMISSIONS. NEED TO LEAN OUT A/F RATIO
Yeah hes still yelling just as loud as when he said #$@! This!! Lol. Jokes aside whats the prob with IAC? Did mine recently. Try cleaning yours before buying, i ruined mine trying to get away with using vice grips so take your time lol
Last edited by me420; Sep 1, 2013 at 07:28 PM.
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Thread Starter
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Joined: Sep 2009
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From: PHOENIX/ TOLLESON ARIZONA
Car: 90 IROC 5.7 1LE CLONE 89 GTA 88IROC
Engine: 5.7TPI / 5.7TPI/ 5.7TPI/ 4.3 CMFI
Transmission: 700R4 UPGRADED 700R4STOCK700R4STOCK
Axle/Gears: 3.23 10 BOLT 3.27 9 BOLT 2.77 9BOLT
Re: 5.7 RUNNING PERFECT WONT PASS EMISSIONS. NEED TO LEAN OUT A/F RATIO
PULLED THROTTLE BODY / TOOK IT APART. DUNKED EVERYTHING IN WD40 FOR A FEW DAYS. PULLED IAC . LOOKED DIRTY . PULLED PINTLE. WORM DRIVE THREADS LOOKED DIRTY. DUNKED IN WD40 FOR A FEW DAYS. BLASTED ALL PARTS WITH THROTTLE BODY CLEANER AND CLEANED WITH TOOTHBHRUSH.
CHECKED IAC 4 WIRE OUTPUT WITH LED AND 470 OHM RESISTOR IN SERIES ( IMPORTANT .. OR POTENTIAL IAC DRIVE CIRCUIT BURN OUT ) POWER AND GROUND PRESENT AT IAC PLUG (KEY ON ENG OFF) WITH NO SHORT TO GROUND (KEY OFF.) CHECKED IAC COILS 50-60 OHMS X 2 . CALLED EM GOOD.
PUT PERMATEX SILVER ANTI- SIEZE ON IAC DRIVE THREADS. SCREWED PINTLE IN AT JUST UNDER 25MM EXTENSION . PUT T/B BACK TOGETHER WITH NEW GASKETS FROM TPI.NET.
IAC CAME BACK TO LIFE. CAR PASSED MULTIPLE TEST DRIVES. COASTDOWN / A/T IN DRIVE. IDLE CONTROL RESTORED CAPTAIN. THIS MITE HELP ANOTHER IN THE FUTURE.
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