2016/02/23 07:47:38
123grosso
I am having ignition problems with my 91 3sgte mr2
There is no spark coming out of the igniter, all the relays have been checked, the afm and igniter both have good grounds

I have found that the ignition relay In the rear bay doesn't activate when the key is on ignition, only when manually activated or when IGN1 and IGN2 are hotwired at the back of the barrel, now when the relay is physically closed by hand the fan in the bay activates and the ignitor has power on pin 3, however when the relay is activated via hotwiring IGN2 the fan does not activate

Also I found this wire broken on the ECU plug.


I also have found my dizzy signal wires are quite brittle, could this be a contributing factor?

Is there a way the ignition can be bypassed as I would be happy to wire the dizzy sensor directly to the ecu and provide the ignitor with seperate power activated by another switch (racecar style)
2016/02/23 18:36:12
antmcbane
Does the CEL come on when the key is switched to on? Despite my car also having dodgy wiring (but continuity for all connections) the thing that made my car stop sparking was a piece of metal inside the afm shorting one of the contacts, this tripped the ecu. I removed the AFM cable (be careful if you do this, you need to flick two little prongs off and then it comes out easily, if you try to remove directly you'll break the circuit board inside) and then the car would start... albeit poorly.
2016/02/23 23:32:04
Guest
Wiring issues, I feel your pain.
Back to basics, get the pin out diagram (lots available in Google search), follow the wiring to ensure all is connected.
2016/02/24 00:05:12
123grosso
Finally sorted it out, the plug going into the distributor had brittle connections so cutting and resoldering those wires did the trick
2016/02/24 00:10:05
TomsMR2
Great that you got it going but you should really deal with all those dodgy joins going into your ECU as well, it's only time before another fault comes up
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