Alright you guys. I searched on here and thought I found a definitive answer as to why my ‘94 SC400 170,000 miles all of the sudden lost power and the tach went to zero when I pushed the pedal.

The consensus seemed to be ignition coil. I even tested by unplugging the driver’s side and the car wouldn’t start - determining it was the passenger side coil.

Well, no, $50 later apparently that’s not it. So, what else could it be and how do I test to see if that is it?

Could it simply be the distributor cap? I recently changed the spark plugs too - if one was loose would the whole passenger side cylinder bank not fire? Can I test if it’s getting spark to the passenger side without pulling the whole freakin air assembly again? How do you test for spark?

I also read that it could be the catalytic converter. Is there a simple test to see if that’s what it is?

Any help appreciated.

Could I have possibly purchased a bad coil?

 

test your igniters?

 

Would you care to elaborate? I don’t see but a handful of posts on ‘ignition modules’…..and those appear to be over 3 bills to replace.

The car feels like there is a vacuum sucking the power from it – if that makes any sense. I’m not sure if that’s just what only half of the motor getting fire feels like or if there is any significance to it.

So, if it’s the catalytic converter – and I’ve got a little micrometer somewhere – I should be able to find spark inside a plug if I can get to one of them without pulling the whole freakin’ breather assembly off again?

I thought I was so slick coming to this site and finding overwhelming evidence that it had to be my ignition coil and those only being $50. Now, I’m $50 in the hole for no reason on this fix and I don’t feel very slick to say the least.

Any help on this is appreciated. Remember that it’s just the passenger side that’s not firing apparently.

 

It still could be the drivers coil, you need to test it with a working coil, rather than just unplugging it and trying to start it, because it won't start.

 

Do you understand that I unplugged the driver’s side coil and the car wouldn’t start? When it’s plugged in the car runs as if it’s running on half the motor and the tach goes to zero when I hit the gas.

From what I read – that is indication that the other coil is your bad coil.

Why would unplugging the bad coil cause the car to not start?

 

I tried the same test for a bad coil, the wouldn't start, so I tested it with a working coil and it completely fixed the issue, I didn't have the tach issue though, so it could definatly be something else.

How's it running? With a bad coil you should be smelling raw gas and only a few cylinders firing.

 

Come on you guys...... I could use some advice here.

 

Ok, so today I pulled the air assembly off to see if the passenger side spark plugs are getting spark and they are……

Does this mean that it’s the catalytic converter on the passenger side?

Could it not be getting fuel to just one side for some reason? ECU?

Help!

 

If it were the cats it would seem like it's lacking in power. Also can u tell they are getting hotter then normal??

 

Have you tried unplugging the MAFS?

 

Ok, I’ve replaced the passenger side ignition coil already because I thought from a search on here that it seemed a sure fire deal that was what was wrong if I unplugged one of the ignition coils and the car wouldn’t start.

Let this be a lesson to others. That is not necessarily the case. I am now suspecting – as you mention – that the distributor cap/rotor on the passenger side is bad……cuz it fires the cylinders that aren’t getting spark.

I didn’t realize that the distributors fired cylinders on both sides of the motor for one – they do.
I will first check the lead to the distributor, but I am confident that it is sending spark.

If it’s the distributor and rotor this would have been a $30 fix instead of blowing $50 on a new ignition coil that I didn’t need making it a $80+ fix (fingers crossed).

I shouldn’t have been so lazy as to just assume it was the ignition coil, but I didn’t really want to pull the entire breather assembly back off just to check the passenger side plugs – and at the time I believed that the entire driver’s side was getting spark.

I’ll report back what I find, but this info might save somebody from jumping to the conclusion that it’s the ignition coil every time when it maybe be an even cheaper fix. Hopefully!

 

Have you tried your new coil on the driver sider and used your old coil on the passenger. Your method of testing does not work that way, been through 4 coils (2 of each of my cars).

The change of ignitors going bad is low, but see if the tach issue changes when you swap the plugs on the ignitors (the plugs can go in either one of the ignitors, so switch them and see what happens).

Tried your plugs? My 1uz MK3 would not start due to 1995 oem denso plugs, quite hilarious actually.

sorry i didnt read this thread through out, thought id drop my opinion before i leave.

 

What the hell is an ‘ignitor’ and where is it? I still haven’t figured this out…… I’ve seen that they run like $350, but I have even spotted them in the engine bay.

If I’m getting fire all the way to the distributor from the ignition coil then does it matter?

Aren’t these ‘ignitors’ before the coil somewhere? Cuz from the distributor it looks like a straight shot to the plugs.......

 

I did exactly what I read on here to do......unplug one of the ignition coils and if the motor doesn't start - then the other coil is bad.

What I believe is actually happening is that the passenger side ignition coil was fine, but he passenger side distributor cap/rotor is fried and thus no spark and no four cycliders to fire up even......

If I had read that here I wouldn't have been so fired up about spending $50 for what sounded like a quick fix when $30 for a cap/rotor would have done the trick, but taken a bit more time to install.......

 

Listen... Have you tried the new coil ON the driver side and used the original coil on the passenger side. I dont care about your "test", I am asking have you physically tried the new one on the other side which you may think is good?