OT: Worked on a '93 Blazer "idle issue" tonight

[Jon K]

So my buddy has a '93 Blazer with a Vortec V6. It would idle sometimes, stall other times. I took a look at it suspecting something like the Jeep idle air control valve being fouled. Turns out, his cruise control cable had snapped at the throttle body housing. Chevy engineers decided that they wouldn't use an idle control valve. In fact, they wouldn't even use a throttle cable adjustment for idle. No, in fact, they'd use the CRUISE CONTROL cable to regulate idle... they rely on the cruise control cable (which has 6 different positions at the cruise control motor) to regulate how open the TB is. So when the cable snaps the TB slams shut (ie., there no other regulating tension) and the engine sufficates. Great design. Also, it appears as though the MAF is built into the throttle body, as there was not one anywhere on the intake track.

Bravo Chevy.

Cable fixed.

[Derek A.]

If memory serves - that motor does use an Idle Air Control (IAC) to meter air into the motor at idle. That vintage of GM injection uses the MAP sensor to determine air flow requirements. Pretty easy stuff to work on - as far as FI goes.

[632 Regal]

I also do believe ther is an idle set screw onder the throttly body to regulate the air but its under and capped so you cant mess with it.
Cable fixed.[/QUOTE]

[Bill R.]

93 blazers, vin code W and vin code Z, if the cruise control cable is doing it then someone intentionally screwed with it and adjusted up all the slack to hold the throttle open.. I would suspect an iac problem and they did this to try to make it idle. The cruise control cable is supposed to have .39 slack in the cable at the throttle body ball stud



So my buddy has a '93 Blazer with a Vortec V6. It would idle sometimes, stall other times. I took a look at it suspecting something like the Jeep idle air control valve being fouled. Turns out, his cruise control cable had snapped at the throttle body housing. Chevy engineers decided that they wouldn't use an idle control valve. In fact, they wouldn't even use a throttle cable adjustment for idle. No, in fact, they'd use the CRUISE CONTROL cable to regulate idle... they rely on the cruise control cable (which has 6 different positions at the cruise control motor) to regulate how open the TB is. So when the cable snaps the TB slams shut (ie., there no other regulating tension) and the engine sufficates. Great design. Also, it appears as though the MAF is built into the throttle body, as there was not one anywhere on the intake track.

Bravo Chevy.

Cable fixed.

[Derek A.]

I saw one of those intakes where the movement of the IAC motor had acutally removed aluminum from the intake - which prevented a seal from the IAC trying to close off the supply of air to the motor.