Understanding Idle Issues

[pinkgrips236]

So I've been having a rough idle issue...

When the van is cold, the idle will hang around 7-8oo, but feel pretty rough. When I reach normal temp, the idle jumps up to about 1000. After driving for a while, the idle will climb even further to 14-1600.

I've gone through the setting procedure, and continue to see this issue. I was also getting a TPS code, so took the throttle bottle off, cleaned it real good, put a new TPS on, double checked my air intake hose and vacuum lines, and things seem to be the same. I also have relatively new cap, rotor, wires, and plugs.

The book lists a bunch of possibilities for rough idling, but I was just wonder if there is a common culprit that I'm missing?

I've also found that when idling around 7-800, my charging voltage drops to 13.5 instead of the 14+ I see while driving.

[ninz30]

Checked for vacuum leaks? Ohm out your o2 sensor, thermostat sensor, and air valve.

[pinkgrips236]

A little progress here...

No noticeable vacuum leaks, new 02 sensor, air valve ok, not sure what exactly the thermostat sensor is...

I also found this page in the manual for the '87. I also have an '89 manual which doesn't have this page, oddly.


The AC idle up vsv doesn't seem to be leaking, and the resistance checks out. I'm not sure what the air valve for AC is, or if I actually have it after removing all the AC components. Water temp switch I'm assuming is the Coolant temp switch? This also seems to be ok, no braking/chaffing of wires.

I still have Code 11, though I am pretty sure that I dialed in my new TPS correctly. I'm still wondering if there's something in the AC system that is giving me this code after removing the AC bits.

Anyone with any ideas?

[llamavan]

Just to confirm, did you clear codes after installing the new TPS? If not, you will continue to get whatever were generated prior to the repair.

Gwen

[pinkgrips236]

I believe so!

I've had the battery disconnected for a bit, reconnected, confirmed that the code was not there, drove around, checked to find the code back.