3fe ignition question (1 Viewer)

[Cruiserman13]

I did the 3fe conversion to my 73 FJ40, the 3fe from a 89 60 and the engine ran fine once installed. I now have no spark. I have voltage to the igniter. According to the service manual I should have voltage to the tigger wire (IGT) at idle, I assume cranking also. I do not. Does the ecu or the igniter power that wire. Obviously one or the other needs replacement. Thanks for any input.

 

[Spook50]

IIRC the IGT wire is the short wire from the igniter to the coil's negative terminal. The coil receives constant power to positive when on, and pulses to the negative terminal signal it to discharge through the high tension wire to the center terminal of the distributor. Unless there's been damage or an electrostatic discharge through the ECU, odds are that part isn't your problem. Unfortunately these igniters generate some good heat, and at this age the thermal compound inside is breaking down so they can't reject heat well and the internal electronics burn out. Its still not a common problem, but not "unheard-of".

There is a documented method to convert the FJ60 ignition to a GM 4-pin HEI style controller, thereby replacing the OEM igniter with something much more readily available (and with higher dwell "performance" modules available too; one from D.U.I.), but what I don't know is if the 60 series ignition and the 62 series with its fuel injection use the same OEM igniter. Not sure if it was ever stated in the HEI thread, but I don't think it was and I hadn't bothered to look into it yet. If they DO use the same OEM igniter, there's no reason the GM style 4-pin wouldn't work on a 3FE application too.

Edit: Here's the thread discussing the HEI conversion if you're curious about this route (if your igniter is in fact the culprit): Igniter Repair for Cheapskates - https://forum.ih8mud.com/threads/igniter-repair-for-cheapskates.802849/

 

[Cruiserman13]

Thanks for the info.

 

[Engineer8000]

Did you install the distributer air filter? If not, the inside of the distributer corrodes and will stop working.

 

[Cruiserman13]

Did you install the distributer air filter? If not, the inside of the distributer corrodes and will stop working.

View attachment 2566481

Yes I did. Mounted it to the firewall. I intend to run the line through the firewall and mount it inside the vehicle. I found the issue for my no spark. My cold start switch failed and shorted to ground and the ecu would not trigger the igniter. I unplugged the cold start switch and instantly had spark. You know how it is, just add parts. My cruiser feels neglected and acts up if I don't replace parts every now and then.