have a 454 with a 800 holley carb. problem is that it is idling too high. 1000rpm. turn the motor off and restart will idle down to 800 and eventually work back up to 1000.Called jegs tech and one tech said it could be the power valve. before i tear the carb down what else could it be

Could be too lean. Try to richen it up a smiggin all the way around and adjust the mechanical throttle screw as needed. I am assuming that you are at the bottom of the adjustment of the mechanical stop?

When you drive it and pull it down in first as you coast to a stop does the engine pop or blub blub blub? Another too lean at idle sign.

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Steve Jack
-Concept One Pulleys and Brackets
-Marketing Technologies Limited
-Northern/Southern Rodder Magazine's "Jack'Stands" technical column author/originator

[This message has been edited by HOTRODSRJ (edited 08-17-2002).]

Did you try adjusting the fast idle setting? make sure car is at operating temperature. shut off engine then hold closed the choke butterfly.with engine still off and still holding choke closed open throttle by hand to wot. start engine should go to 2,000 rpm if it does not then u need to adjust fast idle screw.If it does idle at 2,000 step on throttle a little and speed should drop down to normal.After recheck curb idle and mixture screw settings and recheck ignition timing.

Your secondaries may be slightly open, or you could have a vacuum leak also. Check for your throttle plates closing properly.

SORRY ABOUT THE CAPS,I TOO BUSY TO PLAY WITH THE SHIFT KEY.

DUE TO YOUR CAR RETURNING TO A RESPECTABLE IDLE AFTER SHUTDOWN AND RESTART I WOULD ALSO CHECK OUT THE FOLLOWING ITEMS WHICH I HAVE RUN INTO OVER THE YRS AS FIXES FOR THIS EXACT PROBLEM YOU HAVE.

I HAVE ASSUMED YOU ARE ADEPT ENOUGH TO HAVE ALREADY ADJUSTED THE IDLE MIXTURE AND KNOW WHERE THE IDLE SPEED SCREW IS ON THE DRIVER SIDE OF THE CARB.

1)ARE YOU RUNNING A VACUUME ADVANCE? IF YES THEN IT COULD BE HANING UP.

2) ARE YOU RUNNING THE VACUUM LINE FOR THE VAC ADVANCE OF A PORT THATN HAVE FULL VACUUM AT ALL TIMES? IF YES THIS COULD BE YOUR PROBLEM. THE VAC LINE SHOULD BE HOOK TO A VAC SOURCE ON THE CARB WHERE THERE IS LITTLE OR NO VAC AT IDLE.

3) DOES YOUR DISTRIBUTOR HAVE A MECHANICAL ADVANCE? IF SO SPRAY SOME CONTACT OR BRAKLEEN ON THE WEIGHTS/SRPINGS ETC AND THEN HIT THE POSTS THEY RIDE ON WITH JUST A TAD OF WD40,NOT TOO MUCH.

4) ARE YOU RUNNING A CAM WITH A FAIR AMOUNT OF OVERLAP/DURATION,THIS CAN AFFECT YOUR IDLE TOO WHERE IT CAN BE UNSTABLE DUE TO LOWER VACUUM LIKE APPROX 8-10 INCH VAC WHERE 16-18 IS MORE LIKE STOCK SO KEEP THAT IN MIND TOO.

5) IF YOUR RUNNING A PERF CAM REMEMBER THAT THEY CAN AT TIMES DEPENDING ON DURRATION NEED MUCH MORE STATIC/LEAD TIMING THAN A STOCKER.

FOR EXAMPLE MY 396 WITH STOCK CAM WAS APPROX 6 DEG BTDC,NOW TIH A FAIRLY MILD PERF CAM I HAVE TO RUN APPROX 16-17 DEG BTDC STATIC/LEAD TIMING. SO IF YOUR IN THIS CATAGORY TRY BUMPING UP THE TIMING,THEN DROP YOUR IDLE SPEED BACK AND SEE WHAT HAPPENDS.

YOUR CARB WOULD HAVE TO BE FAIRLY OUT OF WACK OR YOU WOULD HAVE TO BE RUNNING A LOT OF CAM OVERLAP LOOSING VACUUM TO BE CAUSING POWER VALVE ISSUES,ETC. IF YOU HAVE APPROX 13-14 INC VAC OR ABOVE THE PWR VALVE SHOULD NOT BA A PROBLEM. MAYBE YOU SHOULD CHECK THE VACUUME TO SEE WHERE YOUR AT AND GO FROM THERE CONCERING YOUR POWER VALVE.

GOOD LUCK....SCOTT

REMEBER,ONLY CHANGE 1 ITEM AT A TIME AND ALWAYS WRITE DOWN OR MARK WHERE YOU WERE SO YOU CAN GO BACK IF IT'S NO BETTER OR WORSE.

If the timing has too much initial advance, then it will idle too high and will be impossible to adjust. Also, check the throttle cable/linkage adjustment to make sure there is enough slack to allow for proper adjustment of the idle speed screw. If the cable or linkage is too short, you won't be able to adjust the idle.