No spark issues

I have tried everything with no luck. I have an 88 4runner with the 3.0 and auto trans. The previous owner claimed the engine was replaced with a 3.0 from a 1993. The engine turns but, no spark. We have already replaced the igniter and coil. Would there be anything different on these two engines that would be giving me an issue? All fuses and relays are good. The 4runner still has the stock ecu so nothing was swapped on that end. Any ideas?
Thank you

 

Find a top mechanic like Scotty Kilmer in Houston.

 

It could be the signal generator in the distributor. It should ohm out to 140-180 ohms. The air gap between the rotor, on the distributor shaft, and the signal generator is 0.2-0.4MM, or 0.008-0.016 inches. It can be adjusted, within limits, by loosening the screws that hold the signal generator on the base plate inside the distributor.

Also, you should ohm out the wires that connect the signal generator to the ECU. Make sure the wires are good, even when you move them around. Make sure you don't have an intermittant connection, or perhaps a broken wire, someplace. Same for the wires that feed the Igniter, and so on, from the ECU. Wires can corrode apart inside the insulation, so not be visibly broken, but sometimes, when you move the wires or connections slightly, the ends can make, allowing everything to work. If that happens, all you can do is replace the wire it's self. Or, if you can find the actual break, replace the few inches of wire on either side making a new wire, in essence. Make sure you solder it in, not crimp. Much better to solder.

Make sure as well, that the plugs on the ECU are good and snug, and none of the wires are broken at their connectors. Make sure the ground on the ECU is good and clean.

You can put a timing light on one of the spark plug wires to see visually that you are not getting any spark. It could be that the spark is there, but the timing is far enough off that it won't start. Did you verify the timing?

Are you certain it's a lack of spark, and not a lack of fuel, or something like that?

I hope something in all my rambling helps...
Pat☺

 

Thanks Phantom Tweak. That helps out alot. I really appreciate it. I will try this today.