I have a 1983 Toyota Cressida (5MGE) with about 200k miles and it was running fine. However when my wife went to get the kids from school it wouldn't start at all. The engine is turning over just fine but no ignition/starting. It has fuel and the timing belt is intact and was verified by watching the cam turn via the oil fill hole.
I cannot get any spark from the plug wires or the coil wire so I'm working up stream to try and figure out why not.
Since it isn't producing any sparks or fire at all I figured the
ignitor had failed as this has been somewhat of a common problem with the older Toyota's. I had picked up a spare ignitor and coil a few years back at a salvage yard. I changed out the ignitor/coil assembly thinking how impressed my wife
was soon going to be when I fixed it but much to my surprise there was no change - still no spark to be found anywhere.
So I humbly pulled out my Toyota factory manual and started testing to try and figure out why there is no spark all of a sudden.
Here is what the factory manual recommends and what I've done.
1. Verified that there is 12 volts getting to the ignitor with the key in the on position - - OK here as I'm getting the 12 volts.
2. Checked that the "power transistor (whatever that is)" in the
ignitor is working by putting 3 volts to one of the wires coming from the ignitor and the other to ground while the key is in the on position. This is suppose to result in a burst of sparks, within 1 second, at the end of the coil wire tip that was disconneted from the distributor cap end. It worked perfectly, as the open coil wire end started sparked almost immediately. I believe this confirms that the ignitor and coil are working OK and not the problem.
3. Next step, per the manual, is checking out the distributor "pick-up coil" by using a multi-meter to check the ohms. I got 153 ohms across both terminal ends (I think one was called NE and the other G) at the end of the wiring connection which is spot on according to the factory manual.
That is the end of the factory manual diagnostics so am trying to think of where to go next. The plug wires are almost new but I cannot get any spark from the coil wire so it appears to be in the primary ignition system. The car has been a daily driver and
was starting and running normally until this happened.
One thing that I have read from other web locations about other makes of cars is that some have mentioned that there should be continuity between the two leads on the distributor "pick-up coil" but the Toyota manual doesn't address this test. I went ahead and did it since I was already there and I did note that my test showed an open b/t the two terminal ends - or no continuity. I don't know if that is pointing to the problem or not since Toyota didn't mention this at all.
Also, I've read about pulling the distributor cap and checking the air gap. However since there is no contact with the pick up coil assembly I don't see why the gap would have grown over time?
I have read that the ECU (computer) is almost never the problem and the manual doesn't even address testing it so I'm hoping that isn't it and I'm trying to rule out the distributor first.
Should I just buy another distributor or is there other test to confirm that the distributor (and pick up coil) is operating properly and sending the signal to the ignitor?
Any thoughts or ideas of what I may be overlooking would be ppreciated.
I cannot get any spark from the plug wires or the coil wire so I'm working up stream to try and figure out why not.
Since it isn't producing any sparks or fire at all I figured the
ignitor had failed as this has been somewhat of a common problem with the older Toyota's. I had picked up a spare ignitor and coil a few years back at a salvage yard. I changed out the ignitor/coil assembly thinking how impressed my wife
was soon going to be when I fixed it but much to my surprise there was no change - still no spark to be found anywhere.
So I humbly pulled out my Toyota factory manual and started testing to try and figure out why there is no spark all of a sudden.
Here is what the factory manual recommends and what I've done.
1. Verified that there is 12 volts getting to the ignitor with the key in the on position - - OK here as I'm getting the 12 volts.
2. Checked that the "power transistor (whatever that is)" in the
ignitor is working by putting 3 volts to one of the wires coming from the ignitor and the other to ground while the key is in the on position. This is suppose to result in a burst of sparks, within 1 second, at the end of the coil wire tip that was disconneted from the distributor cap end. It worked perfectly, as the open coil wire end started sparked almost immediately. I believe this confirms that the ignitor and coil are working OK and not the problem.
3. Next step, per the manual, is checking out the distributor "pick-up coil" by using a multi-meter to check the ohms. I got 153 ohms across both terminal ends (I think one was called NE and the other G) at the end of the wiring connection which is spot on according to the factory manual.
That is the end of the factory manual diagnostics so am trying to think of where to go next. The plug wires are almost new but I cannot get any spark from the coil wire so it appears to be in the primary ignition system. The car has been a daily driver and
was starting and running normally until this happened.
One thing that I have read from other web locations about other makes of cars is that some have mentioned that there should be continuity between the two leads on the distributor "pick-up coil" but the Toyota manual doesn't address this test. I went ahead and did it since I was already there and I did note that my test showed an open b/t the two terminal ends - or no continuity. I don't know if that is pointing to the problem or not since Toyota didn't mention this at all.
Also, I've read about pulling the distributor cap and checking the air gap. However since there is no contact with the pick up coil assembly I don't see why the gap would have grown over time?
I have read that the ECU (computer) is almost never the problem and the manual doesn't even address testing it so I'm hoping that isn't it and I'm trying to rule out the distributor first.
Should I just buy another distributor or is there other test to confirm that the distributor (and pick up coil) is operating properly and sending the signal to the ignitor?
Any thoughts or ideas of what I may be overlooking would be ppreciated.