Mr.JTurboII

Im having this problem i cant figure out. if i clutch in from any gear and put it in neutral, it stalls on decel, like theres no idle. however if i leave it in gear for decel to anything under 1500rpm and then clutch in, it holds idle. idle was raised to 1000, tps was adjusted, made no difference. its an s4 t2, no emissions, no bac.

satch

iTrader: (1)

Check the clutch switch pin at the ECU. It should read 12 volts when the clutch is depressed.

The BAC prevents the idle from dropping below 750 rpm. Not having a BAC is likely not helping the situation.

arghx

iTrader: (3)

you removed the things that keep the car from stalling, like the BAC valve and the dashpot.

Mr.JTurboII

Will check the clutch switch at the ecu.

Everything was removed years ago and it ran perfect, even using a/c. Problem recently started happening and getting worst.

Mr.JTurboII

i checked the clutch wire at the ecu and i get ground signal when the clutch is depressed. i ended up adjusting the clutch pedal sensor a little bit because it seemed to be in too much. it seems to not want to die anymore. but im not 100% sure because the idle kept raising for itself, i just realized im missing the lock nut for the idle adjustment screw.

satch

iTrader: (1)

Both the pinout and wiring diagram suggests the voltage to the ECU should be 12 volts w/the clutch depressed. W/no key in the ignition you can try checking for continuity on the two wires at the switch when the clutch is depressed and when the clutch is not depressed. It should show continuity between the B/Y and Y/L wires w/the clutch depressed and no continuity when not depressed. If you have no continuity under either situation then the switch is problematic. If the switch was working properly the idle should rise a bit as that's the role of the switch being connected to the ECU because it creates load on the engine when depressed and the ECU tries to make an adjustment.

Mr.JTurboII

Satch you are the man!!!. So I looked at the switch, the B/Y had solid ground with ignition on. I cut the wire and temporally connected it switched 12v. Took the car for a run and it didn't stall. Thanks again.

satch

iTrader: (1)

That B/Y wire is powered by the meter fuse so it definitely should have 12 volts w/key to on. If that particular wire had no voltage and the other B/Y wires powered by the fuse had no voltage then a host of other items would not work such as the dash gauges and back up lights etc. If they work then I would guess that the B/Y wire at the clutch switch has decoupled from the B/Y wire it is supposed to be tapped in to. There will probably be two stop light switches on your brake pedal. The one w/the B/Y wire is the one to focus on. W/key to on the B/Y wire should have voltage. This B/Y wire is coupled to the B/Y wire found at the clutch switch. If the B/Y wire at the brake pedal has voltage w/key to on but the same wire at the clutch pedal doesn't then the staple joining the two wires has probably come loose. W/no key you could use the multimeter set to continuity and place one meter lead to the B/Y wire at the clutch switch and the other meter lead to the B/Y wire at the brake switch and the meter should ring out. If no ringing occurs then the wire at the clutch has decoupled from the B/Y wire it needs to be connected to.