I just got a 1993 Isuzu pick up with a 2.6. It was running bad and I gave it a tune up. It runs great now except when it is at idle, It will sometimes run good and then bogg down, and sometimes the idle will go up and down. Please help if you can.

 

Is it fuel injected?If not there is a screw on the carborator that you can loosen to help the idle. You can make it the perfect idle.

 

My '92 4x4 has the 2.6 fuel ingected as well. (145,000 km) My problem is that after the truck warms up, the idle sticks up at about 2200 and won't drop. Once it sits turned off for awhile it drops back to below 1000. Back driving and it goes up and sits up there again. Seems to have a mind of it's own.
Truck runs great but I hate to waste all that fuel idling at the stop lights.Any ideas, as well.

 

FOR THE 93,CHECK FOR VACUUM LEAKS AROUND THE INTAKE AN LOOK AT ALL YOUR HOSES GOING TO THE INTAKE ON THE PASSENGER SIDE,MAKE SURE NONE ARE LOOSE.


92 GUY,SOUNDS LIKE YOUR CABLE MAYBE STICKING,HAVE YOU CHECKED THAT?ALSO CHECK THE THROTTLE LINKAGE THAT THE CABLE CONNECTS TO.DOES IT RETURN BACK TO THE CORRECT POSITION?..ALSO ON BOTH MODEL YRS.THE VACCUM SWITCH ON TOP OF THTE T-STAT HOUSING CONTROLS IDLE ALSO.ESP HUNTING IDLE PROBLEMS.AS COOLANT TEMP HEATS UP THAT VALVE BY-PASSES EXTRA AIR TO HELP IDLE.THERE IS AN IDLE ADJ SCREW.ON THE T-BODY..FIRE-WALL SIDE.THAT YOU CAN ADJ.IT,S FACTORY SET .BUT OVER TIME VIBRATION THROWS IT OFF.YOU SHOULDNT HAVE TO TURN IT MUCH.WHEN THOSE VALVE GO BAD,IT STAY S OPEN AN CAN RAISE THE IDLE LIKE A BAD VACUUM LEAK WOULD DO,AN ALSO LAST BUT NOT LEAST THE PLASTIC INTAKE HOSE RIGHT ABOVE THE HEAD AN EXHAUST AIR INDUCTION,MAKE SURE THERES NOT A HOLE IN IT FROM THE HEAT OF THE EXHAUST.YOU HAVE TO RUN YOUR HAND UNDERNEATH TO FEEL IT,YOU WONT SEE A HOLE,UNLESS YOU TOOK IT COMPLETLY OFF.AN MASS=AIRFLOW SENSOR SOMTIMES GOES BAD,NOT OFTEN,I JUST REPLACED ONE AT THE DEALERSHIP AN IT WAS 700 DOLLARS O.E.THANK GOODNESS THEY DONT GO BAD OFTEN.


IV,E BEEN HERE 5 YRS AN IT WAS THE 1ST I HAD REPLACED.Edited by: ISUZUGURU

 

Thanks Guru, I'll take a look at those things and see if any of them help. Funny, but since I added my post the truck has been working perfect so you all must of scared it into good behavior. Appreciate that muchly.....