1987 Toyota Corolla 4age trouble code # 6

Hello everybody, I am a retired thirteen years techicnal editor with Alldata Automotive Repair Information Technologies, located in Elk Grove, CA. Last month, first of March, I replaced my bad head gasket and timing belt. Prior to this repair, my 679,500 miles, Toyota FX 16, was running fine. On first start, code #6 poped-up too my dismay. I have traced relevent circuits, changded distributors, re-gaped the pick-up coils, test the distributor for resistance and high voltage to the cap and rotor, replaced the computer, with a good working spare and changed the igniter and installing an additional grounding wire. The check engine light will not extinguish. My next CA smog test is a year and four months away, I have to turn off this check engine light before than. Please advise!

The measuments are as follows:

1. Coil primary coil resistance is 0.9 ohms.
2. Secondary is 13,200 ohms.
3. Coil energised negative terminal is 12.85 volts.
4. Coil energised positive terminal is13.6 volts
5. G+/G- coil reisitance is 143 ohms.
6. Ne coil resistance is 158 ohms.
7. G+/G- energised is .58 volts at the ECM.
8. Igt to E1 at idle is .79 volts.
9. Igf idle at the ECM is .70 volts.
Is the IGf circuit responsible for turning off the check engine light? If so, what is the problem and fix.

I found this in researching your problem... from an 87 as well with a no Ne signal.

"I found the problem!!! The ECU and Igniter are not component that fail very often, the problem is the wire. The main engine harness contains two wires from the ECU that are spliced and split into 4 wires at the injectors. For some reason Toyota decided to splice this circuit inside the largest portion of the wire bundle. The problem with this is that where the two wires (white with blue tracer, and white with red tracer) from the ECU are spliced with the four wires from the injectors(same colors as above), the insulation is removed exposing the copper conductor to potential corrosion and breakage. Upon inspection, these wires may appear to be fine, and may even ring out when tested with a continuity meter, but in my case, the corrosion had progressed beneath the wire insulation for 8-10 inches, and compromised the copper and it's ability to carry the pulse signal to ground through the ECU circuit.
The fix is to remove the tape and protective coating from the main harness between the intake manifold and the fuse box under the hood, you may notice green corrosion on the wires in question where the mechanical crimp splice is made. 10-12 inches of these wires may need to be removed and replaced with new copper conductors. Both sets of conductors from the injectors are common, so you'll need to figure out how to properly connect the two leads from the ECU to the 4 leads from the injectors. In my case I trimmed the wire back until I had good continuity to both ends, and soldered new leads on, encasing them in 3M scothcote electrical coating and heat shrink insulated tubing".

Thank you very much Scanner John, I woulld have never found the problem. Thank you very much.
Kenneth Gilbert

Hello Sanner Danner and John. I just turned # 6 code off!!!! The problem was bad ground under the distributors Ne pick-up coil. Engine oil residue had collected between the coil frame and the distributor. I removed the distributor from the engine, removed both Ne and G+/- coils from the distributors housing, sprayed the coils and distributor housing with carburetor cleaner to remove the oil film. Also, remove the two Ne connector terminals and polish them to a bright brass finish. Reinstalled the coils, installed the distributor, started the engine and set the timing. THE TERRABLE CODE #6 IS GONE FOREVER!!!!!!!!!!!!!!!!!!!!!!!!YEPEEEEEEEE.
The problem was an oil insulation between the coil frame and the distributor housing. THE FIX IS: Clean the grounds and the dredded code #6 will be history.
I will be lerking in the shadows of Scanner Danner from here-on-in.
Kenneth Gilbert