1994 Isuzu Trooper Irattic idling
I have a 1994 Isuzu Trooper 3.2 V6 SOHC.
Since replacing the Battery, the vehicle idles at 2000 rpm on start up, then very slowly
drops to 900 rpm.
As soon as I touch the accelerator the revs jump back to 2000.
The vehicle drives normally, but when I stop, the engine "hunts" between 1250 and
1750 rpm, then goes up to 2000 rpm, then drops to 900 very slowly.
I was advised on internet to check the Idle Air Control valve, which I found gummed up
and replaced with a new one.
This does not seem to have solved the problem. Very occasionally the engine runs
normally, then the next start up reverts to the problem
Check the throttlle position sensor,if bad it will cause this.
Do what T S T stated first, if you don't find a problem there then do this: Disconnect a battery cable, positive or negative your choice, turn on the headlight switch, this will discharge the capacitors, wait at least 60 seconds, reconnect battery cable, block wheels and set park brake for safety, start engine if automatic put in drive and turn on all accessories ie A/C, fan, headlights and let idle for approximately 2 to 3 minutes, you will know when the idle becomes stable, put into park, shut everything down and turn off engine, you have just done a ECM relearn. If everything else is operating properly this should take care of your idle problem.
Many thanks for your prompt replies, it's been over a month and I was getting desperate. Before I received your replies, I queried adjusting the "Idle Control Valve" on another site, and the reply was: After fitting the IACV, turn the ignition on, pause, turn ignition off pause. Do this at least four times, and the IACV will adjust itself. I did this, and for the last 2 days the Isuzu has been running like a bird, no problems whatsoever. FYI The Trooper has done 300,000 Km, and to date I have replaced: 1 Clutch, 1 Timing chain Tensioner, 1 HT lead, repaired starter motor and fitted new timing chain every 100,000 Km (Plus 1 IACV) I am an avid camper, so the Trooper has pulled a 2000 kg off road caravan in Mountainous areas. Best vehicle I have ever had.
Looking for a Used Trooper in your area?
CarGurus has 91 nationwide Trooper listings starting at $2,900.
Search Isuzu Trooper Questions
Isuzu Trooper Experts