Cooling System: "Heavy-Duty" Flush
"Heavy-Duty" Flush, in Prestone's words...
Drained system and thoroughly rinsed. Refilled with plain water and flushing solution. Drove from Riverside County to Anza-Borrego desert, to camp in Salton Sea, then finally to Salvation Mountain and Slab City.
Memorial for friend who passed away while driving out of the Anza-Borrego desert after easy exploration:
Salt Creek Primitive camp on northeast shore of Salton Sea I had the whole beach to myself
Ruby Tuesday at Salvation Mountain...
Upon return home, drained,thoroughly rinsed, drained, and did the following:
Removed thermostat, cleaned thermostat housing, cold start injector timer switch, coolant temp sensor (ECU), temp gage sender, and the coolant temp sensing vacuum switching valve (I'll research official name later). Installed 2-stage thermostat. Also tested the CSI timer switch (brown connector) and coolant temp sensor (green connector).
Thermostat housing has lots of scaling. Picture shows after I soaked it in vinegar and steel-brushed. Although not that critical, I think that every little thing we do to help the cooling system is good.
Scale on threads for CSI timer switch. Contact between clean bare metal of CSI timer switch housing and shiny bare metal of engine block is critical because CSI timer switch provides ground to CSI in order to turn it on.
Location of temp-sensing VSV and sensors:
Also shows shiny, silver metal on threads for CSI timer.
Temp-sensing vacuum switching valve:
Badly scaled. I think this does not allow it to read temperature accurately. May contribute to hard cold start. (Would appreciate info on this).
AC Shut-off Temp sender ( Not sure of official name) also badly scaled:
Cleaned:
Replaced original (left) thermostat with the 2-stage thermostat from LC Engineering. According to LCE, TAMA makes the 2-stage thermostat for Toyota. I paid $40 plus shipping for this. Other stores may carry same TAMA P/N for less.
TAKE-AWAYS:
I think the following would help with my hard cold stars:
Thorough cleaning of the CSI timer switch housing and the receiving thread because that's where CSI timer switch grounds on terminal of the CSI in order to actuate it.
Thorough cleaning of the temp-sensing vacuum switching valve because it may affect idle. Would appreciate correction if I'm wrong.
Chemical flushing of cooling system alone may not be enough. Best to mechanically clean (steel-brush, etc) accessible parts.
CONCERN:
I tested the CSI timer switch:
STA - STJ, STA-GND readings were good.
However, FSM does not list spec for STJ to GROUND. This is actually the more critical spec because CSI timer switch grounds negative side of CSI during cold cranking in order to activate the CSI. Anyway I measured it at 68ºF and STJ to GND read 16 ohms, but later after sitting around, it read 125 ohms! In the morning before I re-installed it it read around 40ohms. This unit could be going bad.
WOULD APPRECIATE INFO ON CORRECT SPEC FOR STJ TO GROUND ON CSI TIMER SWITCH.