Hunting idle 675-725rpm - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

YOOT · 09-24-2003, 17:07

Car was idleing in the driveway in nuetral with the A/c off, it was warm and Ihad done about 10kms or so in it and the idle was swinging up and down about 50rpm. Wierd, never done it before.

The car isn't missing, it has heaps of power and runs smooth. But the idle in nuetral is going up and down 50 rpm constantly.

It doesn it with the a/c on but at a higher rpm.

I heard it coul dbe the power steering pressure switch, or maybe the ISC valve.

It doesn't shudder when it idles, well not much.

Any ideas?

09-25-2003, 07:09

675 is way too low dood, increase your idle to 700+

YOOT · 09-25-2003, 14:20

well it does idle at 700 normally, but it started hunting about 25rpm above and below that yesterday.

Wierd.

3Toed · 09-25-2003, 14:51

I thought non-XR Falcons idle at 550 RPM and XR's at 750 (or close to) RPM? I know that once my engine has warmed up it idles at around 570 RPM (shown using the EL dash diags).

Recently my car has started hunting at idle and only after a spirited drive. Mine however hunts between 500 (or could be high 400's) and 800 or so. Hasn't stalled so it doesn't bother too much at this stage. Will get it checked when I next send it in for a service.

Interesting comment about power steering though. After getting my plugs, leads, dizzy cap, rotor button and battery changed (due to missing) I went to the shops and on the way back I lost power steering. I don't think the car stalled (it's auto) but I turned it off, waited 5 seconds, turned it back on and it was fine (sounds like Microsoft standard operating procedure

).

Weird...

09-26-2003, 07:58

Well EA's seem to idle around 730RPM-750RPM, thats where I would be setting the base idle to on your car. Stick a accurate tacho into the wire with the round connecter near the brake booster, and then turn off your air con and all that stuff and set your base idle a bit higher.

JC-XR8 · 09-27-2003, 02:00

I had a bad idle on my EF - at a set of lights, it would idle so low that the oil warning light would come on. The plugs and leads were brand new when i bought the car, so I tried cleaning the ISC valve - seemed to work for a day or so, then i replaced ECU. This made it better, but still not great. I adjusted the base idle up about 50rpm (to 750) - again better, but still not happy!

As well as that I also had this sort of 'stutter', or flat spot, where the engine would sort of go along with no power, then all of a sudden it would rev freely with heaps of power - sort of like turbo boost.

I removed the Oxygen sensor, which made the car idle at around 1100-1200 rpm, but the stutter was gone. Reconnected the O2 sensor - stutter was back. Bought a new O2 sensor - car is now fixed, though I will have to see how it goes on cold start now.

ebxr8240 · 09-27-2003, 02:16

I think the 6 has a senser on p/s to prevent low idle and surging issues...

YOOT · 09-28-2003, 15:53

Ok - hows this, the car stinks, it smells like rotten egg gas. So far the idle isn't playng up but I think it is running really rich. So I think I'll get the O2 sensor checked, it could be cactus.