I have a 1991 Camaro rs with the 305 and I have.

DID YOU SNATCH THIS OUT AND CLEAN IT AND THE HOLE IT WAS IN?

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_idle-air-control-valve-bwd_5012678-p?searchTerm=iac

KEEP US POSTED

THE MEDIC

NEGATIVE (WAS HOPIN' YOU HADN'T TRIED IT YET--AND THIS BE THE CURE!)---IF IT WERE ALL CARBON-ED UP (EVEN IN THE HOLE) AND YOU GOT IT ALL CLEAN

THIS MIGHTA BEEN YOUR PROBLEM......MAYBE YOU DIDN'T CLEAN IT ENOUGH?

IT ALSO MIGHT BE THAT THE PART IS BAD.......IF CLEANING IT WELL MAKES ANY IMPROVEMENT----YOU MIGHT THINK ABOUT REPLACING IT

PULL THE EGR AND GIVE IT A GOOD CLEANING TOO....CAN'T HURT

I AM NOT SAYING TO SPEND YOUR $$$ JUST TO "PARTS SWAP"

HERE'S MY EXPERIENCE WITH A FOR COUNTERPART

https://www.2carpros.com/questions/2006-ford-fiesta-engine

LET ME KNOW--BEFORE YOU BUY STUFF---I CAN MAYBE HELP YOU SAVE A LITTLE

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SEE IF YOU CAN FIND THIS ON YOUR ENGINE

http://shop.advanceautoparts.com/webapp/wcs/stores/servlet/product_egr-valve-bwd_18480153-p?searchTerm=egr+valve

SHOULD JUST SORTA SMACK YOU IN THE FACE!

SOMETIMES CARBON IS SORTA GRAY IN COLOR AND MAY APPEAR TO BE PART OF THE ENGINE CASTINGMAKE SURE YOU CLEAN ALL THAT YOU CAN

THE MEDIC

I'LL SEE IF I CAN FIND ANOTHER EXPERT TO ASSIST

THE MEDIC

At the throttle stop screw, place a piece of thin card board in between and test if the idling speed stabilises. If yes, you might need to adjust the throttle stop screw ( not advised nor required under normal circumstances).

THIS IS SORTA AN EXPLANATION TO WHERE KHLow2008 IS GOING WITH THIS

I'M NOT THAT SKILLED AND EXPERIENCED. YET?

EVEN WITH A CARBURETOR, THE OPENING OF THE THROTTLE PLATE IS SORTA SYNCHRONIZED OR FITTED WITH PROPER SIZED GOODIES INSIDE SO THAT THEY "WORK TOGETHER" AS MORE AIR AND FUEL IS INTRODUCED IN

THIS IS VERY CRITICAL WITH A COMPUTER MAKING THE DECISIONS MANY TIMES A SECOND AS TO HOW MUCH FUEL TO INJECT AND OTHER TASKS IT MUST PERFORM

IT GETS INFO BUILT WITHIN---AND "REAL WORLD" INFO THAT YOUR CARS SENSORS PROVIDE

IF SOMETHING AIN'T RIGHT IT REVERTS/ DEFAULTS BACK INTO A STATE KNOWN AS "CLOSED LOOP" IN ORDER TO CONTINUE TO RUN. THIS MODE IS NOT EFFICIENT. AS IT IS RUNNING BASICALLY ONLY ON FACTORY SETTINGS

"OPEN LOOP" IS WHERE THE CAR IS RUNNING ON INFO COLLECTED BY THE SENSORS, WHICH ARE PICKING UP CONSTANTLY CHANGING DATA IN THE "MODE AND ENVIRONMENT" YOUR CAR IS "PRESENTLY IN". THIS IS HOW YOU GET GREAT PERFORMANCE AND EFFICIENCY WITH YOUR FUEL. FOR INSTANCE: 55 MPH IN THE THIN AIR AT DENVER COLORADO. THEN YOU FLOOR IT!----THEN YOU TRAVEL TO FLORIDA THE NEXT DAY----THE FACTORS CHANGE!

NOW SORTA MORE ON WHAT Y'ALL ARE PRESENTLY DISCUSSIN'

THE OLE THROTTLE SCREW IS NORMALLY USED ON A COMPUTER OPERATED CAR TO SET "BASE IDLE"

THIS BASE IDLE IS SORTA THE "ZERO" IN WHICH THE COMPUTER RECOGNIZES THE POSITION OF THE THROTTLE PLATE (IT KNOWS WHERE, BECAUSE THE TPS [THROTTLE POSITION SENSOR] SORTA TELLS IT!

THE WHOLE SYSTEM SORTA DEPENDS ON WHERE "THIS IS. AT THAT TIME. WHEN THE OTHER IS HAPPENING"----MANY THINGS ARE DEPENDING ON WHAT THE OTHER ONE DOES

AS THE THROTTLE GETS OPENED--AIR ENTERS AT EXPONENTIAL RATESTHE COMPUTER MUST KNOW HOW MUCH, AS YOU STEP ON THE GAS---OR LET OFF

INDISCRIMINATELY MESSING WITH ADJUSTMENTS WITHOUT METERS AND PROPER TOOLS OR SOME EXPERT SORTA GUIDANCE WILL THROW THINGS INTO HELTER SKELTER. THE COMPUTER TURNS EVIL AND IS NO LONGER YOUR FRIEND!

JUST A STUPID IF: NOW YOUR CAR THINKS YOU ARE IN FLORIDA CLIMBING A 20,000 FT PEAK WITH THE THROTTLE WIDE OPENWHEN IN REALITY YOU ARE DOIN' 30 IN THE MIDDLE OF A SMALL KANSAS TOWN

STAY WITH KHLow2008, HE'LL GET YOU STRAIGHT. IS THIS CLOSE TO RIGHT KHLow2008?

THE MEDIC

If that card board trick works I wouldnt adjust that screw I would suspect the idle air control valve not opening enough to let it idle correctly. Thats where I would start.

Your welcome have you done a fuel pressure test yet?

CJ, hopefully we are close to the source.

Camroguyrs91, when idling is not stable due to the throttle opening, it can affect the TPS performance and this can result in hesitation.

Did you test the TPS voltage at closed throttle?

Saturntech9, thanks for filling in the blanks. We seems to have a rapport to be able to understand what each of us is thinking, lol.

Try the following and refer to chart for the correct reading.

V6 THROTTLE POSITION SENSOR

NOTE:
Not all TPS are adjustable.

Throttle Position Sensor (TPS) can be adjusted using "Scan" tester or the following
procedure.

1) Ensure engine is at normal operating temperature. Install 3 jumper wires between
TPS and TPS wiring harness connector.

2) Turn ignition on with engine off. Connect a DVOM to Dark Blue and Black wire
terminals. With throttle at closed position, adjust TPS to obtain specified voltage. See
TPS ADJUSTMENT VOLTAGE table.

3) Tighten screws and recheck readings. Turn ignition off. Remove jumper wires and
reconnect harness connector to TPS.