hi, like a fool i ran the gas tank run too low and since then the tick-over continuely hunts,500rpm-800rpm. being auto this causes problems in traffic and manouvering. at its worst the revs drop-off and it stalls.
i have used injector cleaner in the fuel tank as yet no success.
running low on fuel may be a co-insident so guys what do i check first.
thanks bokker.

 

You could try disconnecting the battery to do a re-learn. The ECM figures out where to put the IAC to get the rpms it requires. Depending upon vintage, you can disconnect the battery and press the brake pedal to de-power the keep-alive quickly. Or disconnect for 15 min or so. The ECM then will have to relearn how to idle the engine.
Maybe.

tom

 

thanks tom i will give that a try tomorrow,i will keep you posted.

 

any chance you picked up some water or debris?

Maybe try a bottle of fuel system treatment. Something with alcohol that will help eliminate moisture in the fuel system.

Keep us posted.

Thanks!

 

tryed disconecting battery and then when that did not work adding the fuel treatment but still the same.
no fault codes flashing but iam going to try to see if there is any stray sparks when it becomes dark.
i fitted an after market air filter, oiled type, last month and now starting to question weather or not this has contaminated any sensors, if so which do i clean first. thanks bokker.

 

bokker,
make sure all fittings are tight around your air filter assembly. Also, check for a vacuum leak.
Both can cause what you describe.
I used an aftermarket air inatke/filter assembly for 100,000+ miles on my 2000 model and never had any problems at all.
As long as you don't overoil the filter, they work just fine.

Do keep us posted.

Thanks!

 

Some oil-drenched permanent air filters will coat the MAF (mass airflow) sensor... and fool the ECM into a wrong value for air coming in... oops. Mess up the idle and also introduce a hesitation on acceleration.
You could also have a ICM, idle control, that is dirty or sticky. It is the mechanism the ECM uses to control idle speed. The actual throttle plates are closed, some do have a specific sized hole, like about 1/4" dia, but the actual idle speed is controlled by the ICM(ECM controlled) allowing air to bypass the throttle plate through a passage that is varied in size by the ICM. Most have a spool valve that moves back and forth to open/close the passage. If it is fouled, it cannot move the spool quickly enough to manage the idle speed smoothly.
You can clean the MAF, but you must be careful. It is a tiny wire just after the air cleaner in, mostly, a metal housing with several wires attached. Latest are heated with a specific voltage, and then the resistance changes as varied by the airflow cooling the wire. The ECM 'knows' the ambient temp, and 'knows' how much it heated the wire, so when its resistance varies, the ECM can figure out how much air is flowing by. With dirt, or an oil coating, the air can't cool the wire at the correct rate.. and you get flustered numbers... and a wobbly idle.
tom

 

hi, all fittings around the air filter are tight and have checked for stray sparkes(in the dark) all ok.
i will clean the icm and the maf tomorrow and let you know the results. bokker.

 

hi, thanks again for your help, brian you were correct it was a vacuum leak. the 90 degree rubber had part slipped off that fits under inlet. the one that leads to the valve cover. problem solved thanks.
a year ago i replaced the pipe due to the rubber crumbling away this time the elbow had deteriated, time to find a better alternative.

 

Hey bokker, that is great news. Glad to hear you found the problem AND it was a cheap and easy fix.
Those are always nice to deal with.

Thanks for the update. It just might help someone else one day.