Spark Knock Sensor Message

[ikeup]

Could someone please help me?

About 2 yrs ago I purchased a mini-motor-home on a 1987 Toyota 1 ton pickup chassis with a 22 RE. I noticed right away that the check engine light did not come on. I traced out the wiring and found that someone had cut the lead from the ECU to the check engine light bulb. I repaired the cut and right away the check engine light would come on and stay on. There were 2 codes. First problem proved to be a throttle position sensor. Replacing sensor cleared that problem. 2nd problem is one I cant figure out. Check engine light comes on between 18-22 miles per hour. Code says it is a knock sensor. No audible pre-detonation heard. Checked timing and it was at 5 degrees AFTER top dead center!!!! Set it to 5 BTC and ran 2 tanks of 93 octane through it. Check engine light still came on. Went in 2 degree increments all the way to around 10-12 degrees ATC, engine light still comes on. Remove lead from knock sensor to ECU, engine light still comes on. Grounded lead from ECU to knock sensor, engine light still comes on.

Could anything else cause the spark knock sensor code? I am out of ideas.

[Bakemono]

My '85 4Runner would do that from time to time. If it was a really hot day, the "service engine soon" light would come on just before I shifted from 2nd to 3rd (about 30 mph).
I never really looked into it because as soon as I shifted into 3rd gear the light would go out, so I figured it wasnt a major concern.
Cap'n