SC400slide

iTrader: (11)

Dont rule the pass side coil out if it hasn't been tested. Otherwise you can end up barking up the wrong tree while the issue was a coil to begin with.

Sc400Jimmy

You're right, maybe I'm jumping the gun on it. I can not locate the passenger side ignition coil for anything, and the AutoZone people say there is only 1 on this car and not two. Very confused because everything I read on the internet says there are 2. Any help locating this second one would be great. Thanks alot

SC400slide

iTrader: (11)

Have you tested that coil by the thermo housing/behind the radiator?
The part sticking out in a square like shape is the ignition coil BTW

Ali SC3

iTrader: (10)

passenger can fail its just less common, test it out and no matter what anyone at autozone tells you that vehicle has 2 coils, 2 ignitor, 2 distributors, 2 rotors and 2 caps. most cars have 1 of these or individual coilpacks but the sc400 is not like most cars, it is in fact much better.
The coils look the exact same if you found one you should be able to find the other one.

fourstars

sometimes these are not obvious. check your TPS, and MAF sensors. they dont have to turn on the check engine light to tell you they are bad. TPS needs to be adjusted every now and then. MAF sometimes needs to be clean. take out a multimeter and do some test. also check the coolant temp sensor if thats working okay. again, check engine does not need to be on to tell you they are bad or not sending correct signal. make sure signals are going through to ecu. signal for temp is important, ECU reads that signal to know how much air to suck, how much fuel to shoot and how much sparks to fire.

Sc400Jimmy

Amazing that you guys are right and auto zone is wrong. I see the second ignition coil now, thanks to your uploaded picture. I'm going to try to disconnect the cable on it now and test it out. This one seems a little complicated because the cable is not out in front like on the driver side ignition coil.

Thank you again, I'll try that now and figure out a way to get to the 2 plug cable

Sc400Jimmy

Alrighty so I disconnected the passenger ignition coil and the car would almost start but wouldn't. So I guess that means in my case it is not the problem. This leaves me feeling really defeated now. I have no idea what the problem could be.

Could this be a simple thing such as just the spark plugs? Judging from everything I described?

I was hoping to would be the ignition coils so I could do the repair myself. Thanks again guys, any input would be great

SC400slide

iTrader: (11)

Well spark plugs would be doubtful but I have owned a couple cars that backfired and ran like crap because the plugs and wires were ancient. When was the last time you changed them?

Sc400Jimmy

I haven't had my spark plugs changed yet since I bought this car last year because the mechanic I took it to told me I didn't need them changed when he saw them. But I did have the cables changed out about 2 months ago.

I noticed something strange under the hood of my car, I posted two pictures. One picture shows you the part I am referring to while zoomed out so you can get an idea of where it is located, and then the other picture shows the section zoomed in.

If you notice, there is a little hose there just hanging loose. There is also a plug looking end that I circled. It's just hanging there as well, but I don't know if these things need to be plugged in somewhere? I don't know if this would be the problem or not, and how they could've come disconnected if that is even the problem.

The middle arrow that I have drawn on the picture is what looks like a place that the loose hose goes into. There are actually two of those little ports there though, you just cant see the other one because its right under the one you can see. The device is labeled "Vacuum" and has other lettering on it. Many thanks again for this help

Jimmy

SC400slide

iTrader: (11)

That wouldnt cause your engine to idle rough. That is your heater control valve. You probably have no heat but you live in Florida so who cares...lol. Below is what it should look like.

Not your issue though...

It seems as though your car might have been meligned with in the past. The vacuum hose directly beneath the LExus logo on the engine isn't in all the way. It wouldnt hurt to poke around and plug all the hoses back in all the way. Probably wouldnt cause issues like youre having but wouldnt hurt. The fact that the HCV was messed with could mean disconnected vacuum hoses. I had one vehicle that the guy didnt even screw the spark plugs in! I thought is was a valve tick but it was the spark plugs just resting in the hole...GL

Sc400Jimmy

Lord knows I've been really trying to get this car fixed myself because I have not had a single good experience with a mechanic and this car.

A part of me wonders if perhaps the used ECU I purchased is bad too. The odds of having two bad ECU's sounds pretty unlikely but I really am beat on this.

The car drives, but to get to 40mph takes about 7 seconds, the gears don't seem to switch at the right times, it's as if something is really wrong with it.

I changed the ECU out myself by just unplugging the original and plugging in the new one, did I perhaps have to program something after that, or reset something? I disconnected the fuse for the dome and the Fuel injecter because I read somewhere that this resets the ECU but again, didn't have luck with it.

My original ECU would give a bad, very very bad smell of fumes to the point of me having to warm the car up and not be around it while it warmed up and would also smell like something was burning underneath the car. This used one I had just put in doesn't seem to do that, but I still have the other problems; rough idle, no power, and strange noises when driving and/or idle.

Yes, there is definitely no need for the heater here!

SC400slide

iTrader: (11)

Well to find out if your original ECU was really bad would be to rip it open and see if any of the capacitors are leaking. There will be brown gel around the faulty capacitor. If your original ECU has that, then it was in need of replacing. How many miles does your car have and the ECU you bought?

Sc400Jimmy

I think that's what I'll do next, try to open the original ecu and take a look around.

My car has 119k miles on it. I'm not sure about the used ecu, I purchased it off of eBay and they only mentioned that it was pulled from a working car.

SC400slide

iTrader: (11)

I just sent my original ECU out for a rebuild and I just went over 150k. 119k is a little early for an ECU to dump, though it is possible. If the ECU was pulled from a working car, I wouldnt worry about it too much.

Read this thread and check off the things you have done and haven't. Go to the last page and see what his issue was. A tiny "stupid 4$ PCV valve grommet".

https://www.clublexus.com/forums/per...n-coils-2.html

Sc400Jimmy

Thanks for the link, I read it and see he had an issue like mine. Unfortunately I think is things are getting a little out of my comfort zone and I may just have to throw the towel in. I believe I'm going to have to go ahead and take it to a mechanic on Monday.

It's hard to find videos on the different things that could be wrong with my car. I felt really lucky that I was able to find the ecu replacement videos, then the help you've given me on how to test the ignition coils. The rest of the possible problems seem hard to find good videos or pictures on. I am very, very new to this and just really hoped I would be able to fix this on my own.

Today's my dad's birthday, he passed away five months ago due to cancer. He took pride in his cars, I thought I would be able to do the same and do this on my own.

Thank you very much for all of your time and help on this, I really appreciate it a lot. Very good to know that there are people out there willing to try and help a stranger on his precious car.