Sc400 Ignition Coil

[Bandit]

I was driving home today and made the turn down my road and when I got back on the gas, NO POWER!

I limped it home and started in under the hood.

This weekend I replaced the Distributor Caps and Rotor Buttons with Bosch replacements. So first thing I did was go back in and make sure nothing was amiss. NOPE!

I then started pulling plug wires from the Distributor Cap. The passenger had no fire. The drivers side popped me real good.

So, I put an ohm meter on the Coil wire and thought great, I found it, a bad coil wire. I go to AutoZone and find a short coil wire, since they do not carry one for my Lexi. I thought I would at least find out if I was correct. NOPE, spark plug and distributor wires are resistor wires and therefore an ohm meter will not register.

I then tested the Coil, no fire. So now I think I need to replace the coil and hope it isn't a problem with the power supplied to the coil.

So now I need to find a passenger side coil.

My question is, where can I purchase a COIL!

[AWJ]

You'll probably have to try dealer parts or call the delear and get a part number and try to get it on-line or cross-referenced locally with an aftermarket piece. Or try the usual online stuff. Google my man - or carparts.com etc.

[Bandit]

I checked around with (4) Lexus Dealers ((2) Nashville, (1) Chattanooga, (1) Knoxville) and the price for the coil ranged from $80 to $120. None of them had it in stock, so they would have to ship to the dealer then ship it to me. It would be 2 days plus an additional freight charge. I then checked Advanced Auto Parts and found it for $64.99 and I would have it the next day. So I ordered it.

I was in Gallatin, TN yesterday, so I stopped by the Lexus Dealer and talked to a mechanic. I told him my problem and that I had no fire on the right coil, I had no error code from the ECU and therefore I felt since it was out of the ECU's diagnostic loop, that it was an end component, either the coil or the lead to the coil. He said that it could be the crank trigger. I then said, if that's the case the left coil would not work either. He agreed, he then said it coil be the cam trigger, I then said, then I would get an error code throught the Check Engine Light. He agreed. I then said, I'm pretty sure it's the coil. I'll replace it. He then said, "I HIGHLY RECOMMEND THAT YOU NOT CHANGE IT YOURSELF". I wanted to laugh, but I didn't and I informed him that I was over 100 miles away and that I would change the coil myself and if this did not fix it, I would consider hauling it in.

I got the coil this morning, went home at lunch and BAM, it is all fixed. My SC400 is firing on all 8 cylinders.

I will probably replace the other coil and the plug wires in the next couple weeks. The Lexi V8 is a very reliable and long lived engine, but some of the external components should be replaced if they are the original equipment. I'm just trying to replace any weak links.

[AWJ]

Glad to see it worked out for ya. At a substantial savings as well I'll bet. Good troubleshooting.

[BlackSC4]

yeah, sweet. ignition coils rarely go bad...but glad it worked for you. this actually brings up another topic...are the MGD or MDG ignition setup superior than the stock setup? do they make it for the sc's??

[AWJ]

MSD is universal. Miller genuine draft is optional. Keep it off the road though. ;)

You can use the SCI or 6AL I think. Might want to have a shop wire it for you real quick though. Won't do much for a stock motor. Fuel economy would probably improve. Search MSD in google.

[chubyball]

Bandit,

Great to hear that you found the problem. Is it easy to fix the inigtion coil? Does your locate on top left front passenger side? I think I am also having a same problem.

[Bandit]

From the Drivers Seat, there is one located on the left front side of the motor and one on the right top center of the motor. Each coil fires two plugs on each side of the engine. So if one goes out, you are not a 2Liter 4 cylinder. IF you pull the spark plug covers, then you can gain access to the Distributors. You can start the engine and start pulling plug wires and see if there are cyclinders that are not firing.

[Bigobigo9]

I can appreciate your posting. I'm having the same issues. I'm going to go ahead and buy new wires, plugs, and coils. Are the coils different from left to right side, our are they the same? Please help. I just wanna make sure I'm buying the right parts.

92 sc400