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From 1986 schematic...
Positive side of CSI gets +12V fr starter relay or neutral safety switch ONLY during cranking.
When cold, contact closes, connecting STJ to ground, and therefore, providing ground to negative side of CSI causing it to spray fuel.
When coolant gets hot, contact opens and disconnects STJ and CSI from ground. When coils get hot after prolonged cranking, contact also opens.
On 1988 22R-E, and quite possibly on later engines, ECU also takes part in grounding STJ when it senses cold coolant. Note the additional wiring (in orange) between STJ of CSI timer and STJ of ECU below.
Joe (ladybugRC), Mark (Chefyota) and other owners of 1987's , when you get a chance, pls check is you have a wire connected to STJ pin of your ECU and let us know what color.
Test specs are here: UNFORTUNATELY, THIS IS MISSING THE MOST CRITICAL SPEC: RESISTANCE BETWEEN STJ AND GROUND. This determines whether CSI gets ground or not. When cold STJ-GND should be low. When hot, STJ-GND should be high. I'll update this post the next time I get the chance to measure actual RESISTANCE BETWEEN STJ AND GROUND.
Also critical is good electrical connection between metal body of CSI timer switch and engine block because this is how it gets grounded. Therefore, threads and other mating surfaces between the two should be bare, shiny metal.
This is not good. I cleaned mine with vinegar and battery terminal steel-brush.
I have an 89 4runner 22RE and replaced cold start switch with a used one that tested good for ohms about 80 out of the intake. Replaced coolant temp sensor also. Still hard starting when cold but after numerous crankings eventually does am I missing something. Is my used time switch ok.
Thank You
Did you read entire post above, and followed recommendations?
Also, as I mentioned, ECU also controls CSI on your model-year. Need good input from ECU temp sender. Once every 30 years ... Clean and inspect ALL temp senders, their connectors, their mounting threads and where thy mount on block to bare, shiny metal, and do NOT use insulating sealant on threads.
We'll go from there.
Last edited by RAD4Runner; 11-26-2019 at 02:48 PM.
So the cold start injector fires when the coolant is 104° and Lower? Is that the case for a 1990 22re ? I thought it only fires when it’s super cold out
According to the manual (completely quoted by Rad4Runner), the CSI "fires" below 10°C for a regular 22re, but below 30°C (pretty toasty!) for a 22r-te. I live in California, where 10°C is "super cold out." YMMV.
12-20-2017, 08:16 AM
cold start time switch
... Clean and inspect ALL temp senders, their connectors, their mounting threads and where thy mount on block to bare, shiny metal, and do NOT use insulating sealant on threads.
