Allright guys.... first post. My 94 sc400 v8 oddly loss power saturday night. Just out picking up some food and she drops power to nill. Tach went to 0, and loss all power. Limped home (half mile) and it was rumming like it had 4 cylinders. Not shaking or missing bad but real down on power. No weird noises, no burning, belts and pulleys and rotating........no idiot lights on. Almost like it's running on half the cylinders. It would read on the tach at idle but if you rev'd it it would drop to zero. Exhaust was present from both tips (clean not smoking). It has 135,000 on it, with very good service records. I was jamming the new stereo (lights dim some) If that helps. Exhaust kinda sounded like a honda with a big pipe on it.... kinda wierd.

Any ideas? How many coils? I really don't know a ton about these rides.


Cats clogged?

 

I would check the coil packs first. We have 2, one on each side of the motor near the rotors.

 

How big is the coil? I read a little more and heard of the same type problems........where are they exactly? Any pics?

 

I don't happen to have any pictures, but if you follow your wiring off the distributor on each side, there will be one additional wire that runs directly to the coil pack. They are both no more than 6-12 inches from their respective distributors.

 

I take it the one coil is on top of the motor close to the pass valve cover at the front. The other is on the driver side at the front of the exhaust manifold. Is this correct? I unhooked both and it would not start. I tried one at a time and it would run with one but not the other..... so it looks as if one is bad! Is this the correct thing to do?

 

Those are the ones! And it sounds like you diagnosed your problem.

 

Sweeeettt I knew I loved this page for a reason!!!

 

Glad to hear it shoes!!! Let us know how it all works once the coil is replaced!

 

Spent $58 for a new coil last weekend. Changed it last night (went on vacation for a week, thats why I'm just doing it), worked great. Took about 25 minutes tops. Started right up, smooth, all power returned.
I looked at the old coil and it had a crack in the top (plug side). Is this common?

PS Make sure you have good tools. Had to go buy some good metric boxed wrenches to get the coil mount off. (14mm) Other than that, it went very smooth and I saved a ton by coming on here and asking questions before having it diagnosed by someone else!

Thanks Club Lexus

 

Good job shoes!!!!

Yup, make sure you have a 14mm, 12mm, & 10mm. Those are the predominant sizes on these cars.

And compared to the dealer, I would estimate you saved yourself a minimum of $500!!

 

Good job Mkorsu -

Jonny

 

This worked for me! ... And I thought it was the Catalytic Converter all along! This forum has saved me literally thousands of dollars! Whew!