Idle surge then no idle

[mlstraw]

I am bringing my 1991 Talon back to life after years in storage. After fixing my fuel supply issue, I have had an intermittent and annoying idle surge. I chose to ignore it as so many DSMs have surge. Yesterday when I came up to a traffic light the engine died and refused to idle. I had to hold the throttle open to get it to run. Got in lots of practice doing heel toe braking.

Once I got it home, I printed out the VFAQ and Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge) and went to work.

The first thing I noticed was there was no rubber plug in the throttle body. Next I noticed there was no idle screw, just a big hole where it should be. I searched around for a few minutes and finally found it wedged between the #4 injector and the runner. After I fished it out and cleaned it up, I put it back in.

I ran it down until it touched and then backed it out 2 turns or so. I started the car and it idled at 700. I then switched on the AC and it stumbled. I backed out the screw anohter half turn and it settled right down.

I fabricated a plug from a silicone earplug.

What could have cused the screw to pop out? Do I need to follow the full procedure to set the screw or am I ok since it idles fine now?

Thanks
Mike

 

[zgarcia]

How does the o-ring look on the biss screw? A bad o-ring could have allowed it 2 back itself out due to engine vibration. i would replace it then follow the full procedure to reset it and you should be good.

 

[mlstraw]

I was so happy to have found the idle srew that I did not pay much attention to the O ring. I just made sure it was still there. I will pull it later and replace the O ring. Thanks for that suggestion.

I have been amazed at how smooth it idles now and how the stumble just off idle is completly gone.