Explosion, now no start.

[vikenabm]

7MGTE ignition system wiring specs


WARNING: post edited - had error in my wiring which I hope I corrected. this is my best understanding of how it is supposed to look.

adapted from another forum, TEWD, and also my TCCS manual from the Allen Instutute training manual from 1990


Coil pack order is: (left to right from front of motor)

Coil pack____________To cyls__wire colors

Coil A Passenger coil____1&6____Black, Tan

Coil B Middle coil_______3&4____Green, Tan

Coil C Driver side coil____5&2____White, Tan

To Engine harness per TEWD:
(Here's where it gets messy! The TSRM appears to have the WRONG pin numbers in their diagram on page IG-15 for the ignitor test procedure, where pin 3 and 4 appear to be labeled in reverse. The test procedure should not work as diagramed because the IGDA and IGDB signals do not appear to be correct. More on this below. Also, the functions from the CPU don't wire to the same function at the ignitor. The functions labeled at the ignitor in the diagram don't make sense and my TCCS manual from the Allen Institute says they are WRONG. The functions from the CPU make perfect sense so I included these in my table below. They mean "IGT = ignition trigger, IGDA = ignition determinant A, IGDB = ignition determinant B, and IGF - Ignition Fail)

CP wiring___CP connector _Engine harness wire color __Ignitor 6 way con._____Function __|_ CPU Activating Function__Ignitor 4 way con. pins to activate
Black__________Pin 1 __light blue/red stripe__________Pin 2______________"IG1" __|___IGT and IGDB__________ 2&3 in TEWD (and TCCS manual)
Green_________Pin 3 ___yellow___________________Pin 4 _____________ "IG2" _|___IGT and IGDA __________2&4 in TEWD
White_________Pin 2 ___light blue/yellow stripe_______Pin 1______________"IG3" ___|___IGT alone _________ 2 Alone in TEWD
Tan___________Pin 4 ___Black/orange stripe_________Pin 3______________"B+" -goes to ignition switch and EFI resistor pin 2


coil firing order: Note coil packs fire vehicle right to vehicle left, ie passenger side to driver's side. . that is how most sources number the coils 1-3 or A-C:

Coil A, plug 1 (and 6 wasted) ie "IG1" , IGDA=0, IGDB=1
Coil B, Plug 3 (and 4 wasted) ie "IG2" , IGDA=1, IGDB=0
Coil C, Plug 5(and 2 wasted) ie "IG3, IGDA=0, IGDB=0

Coi. A, Plug 6 (and 1 wasted) IG1 again
Coil B, Plug 4 (and 3 wasted) IG2 again
Coil C, Plug 2 (and 5 wasted) IG3 again

SO to test the ignitor, it should be the following procedure:

Apply a constant +3v where indicated in first column then touch pin 2 with a +3v pins on the ignitor 4 pin connector:

constant 3V transient 3v read resistance
none ignitor Pin 2 coil C connector (center coil) white wire pin 2
ignitor Pin 3 ignitor Pin 2 coil A connector (passenger side coil) black wire pin 2
ignitor Pin 4 ignitorPin 2 coil B connector (driver side coil) green wire pin 2

Note: my digital voltmeter, which is a high end model, does not respond quickly enough to reliably see the drop in resistance in the coil connector wires. I made a bracket for my plugs to watch them fire and confirmed that they work as expected when wired and tested this way.