Idle drops when coming to a stop when car is warm
 

Heres what's happening:

Start car first thing in the morning, idle is low and fluctuates a little. Drive around the corner, by the next time I stop idle is smooth at around 900rpm. I get to where I'm going no problems.

An hour or two later, start car. Idle is normal. Say I reverse out and come to a stop, idle will drop and the engine will die. Drive a bit more, before coming to a complete stop, push clutch in - idle drops and car dies.

As the car warms up, the idle still drops pretty low, but it doesn't die.

I get the same symptoms happening when driving first time in the morning provided I drive hard enough to get it running pretty warm.

Other symptoms: Bit of hesitation when giving gas if the clutch is in (if the car is warmer this will sometimes kill the engine).
Lower rpms; the car is very shaky when not giving any gas. Particularly in third gear 1500-2500rpm.

Car is 1st gen with 13B Turbo, LTX8 fuel and ignition. I don't know what injectors I have (or how to tell) but from my reading of this message board the problem could be related.

Mine has a weird idle problem too. Yesterday it was idling around 900rpms, and then I adjusted it to a rock solid 750rpms, and it stayed running. Now when I drive it around, or start it it wont idle at all, it dies.

Could just be running too rich. Mine is right now since the air temps have dropped dramatically since the initial tuning in the summer. It has stalled a few times on me and you can smell how rich my car is and feel it in the midrange and topend.

I need to play with the cold start values also.

Here's a theory...(mostly cuz I'm having the same issue on occasion).

When it wants to do that at a stop, yank the handbrake, and let off the brake pedal. What happens to the idle? Mine climbs back up!

It should be noted, that at idle, I'm getting ~12.75-12.82V and pulling around 16" ~750-800RPM.

I noticed the same thing if I was driving at night with the lights on, when I would brake the extra draw was enough to almost make the car stall. I don't see any voltage compensation settings, other than those for an electric fan. Does the Microtech not have any voltage compenstaion settings? That just seems stupid.

Hmmm, YES!!
Took the bus to work on Thursday, drove the car first time at night so I was expecting it to perform normally. Put the lights on and it started doing it!

My voltage indicator seems to indicate 12-13 as well. Is this something a bigger alternator can fix?

When you turn on your lights and accessories, you'll notice not only a voltage drop, but also your vacume will drop as well.. go over to the points on your map that control this area and increase fueling..ie: If you are idling at 750 rpm and 15" of vac, increase the fueling points at the 500 rpm point at both 20" and 25" vac ... you may also want to advance the timing by 1-2 degrees at these points, as the extra advance will help in keeping the car from stalling as the revs drop down to these points ... don't put too much advance in though or else you'll start to get a bit of a loping idling..

Hmmm, apparantly my master brake cylinder is starting to go. Leaking some brake fluid very slowly. Could this be related? It appears to be leaking near one of the vacuum hoses.

it sounds like your idle settings are a little lean, try adding some more fuel in there,

what are you timing figures?

also is the TPS set correctly, and it dosent jump back and forth from 0% to 1-2%??

Dale

Hey dale, when i had my s4 running, everytime i would put the car out of gear whether rolling or stopped, the car would wanna die and it would almost switch off and then come back alive, it would only do it when the engine bay is warm.

Yeah thats what's happening for me, when the engine bay is warm it wants to die when the clutch is pushed in.

i have also experienced my car idling badly with the clutch pedal depressed when parked and the car stalling out when coasting to a stop with clutch pedal depressed.

its just too lean on the idle settings, add some more fuel in the maps around the idle point, try adding a few deg more timing as well

will do thanks for the help!