Fixing the rough (poor) idle issue on my Lexus sc400

Are you having a idle problem in your sc400? Watch this video to see how I fixed it. Every situation is different, lucky for me the problem was a very simple sensor. I Started with off by addressing all of the obvious problems. And after a a couple of hours with out success I realized The problem was in front of my face the entire time. I hope this fixes your issue. like comment and Subscribe.
Shout out to Mr Gaza for sending helpful pictures of his engine and Darryl Geller for replacing the capacitors in the ecu.
Hit up Darryl Geller for all of your ecu repair needs. / roadrunner4444
Follow Mr Gaza
/ @gazaperformancegaragegpg
Follow us:
@Edward3jr / edward3jr
@purritoracing / purritoraci. .

[@xavieuhr]

ANYBODY WHO HAS A MISFIRE AT LOW IDLE AND HESITATION. I just threw in a new coil ignition pack (drivers side nearest AC) and it worked first shot :)

[@bradrewold2072]

Man seriously great vids for the community I’ve never worked on my car this throughly and this gives me the opportunity to delve into my sc400. Great production as well; well shot and well explained 👌🏼

[@Edward3jr]

Thank you! I appreciate this feed back!

[@skkrrtskrrt1470]

The last person probably messed with that idle adjustment because the car was running shity they felt it was a solution the hose that you replace should have been 90% of the problem

[@emmawilson9344]

Wassup hey what's the guy that repaired your ecu and where can I find a tranny for my 97 sc 400

[@jvst20051]

Link to that guy who fixed your ecu please

[@kurt8986]

u get iac at junkyard u say?

[@jrp3197]

i aspire to have 300000000 sc’s like you one day

[@Edward3jr]

Thank you! and when you do, let me know if you have any questions.

[@RobertSmith-js2kz]

Excellent video. Your methodology, diagnostic order of operations etc was perfect. With these cars you HAVE to know the computer is up to snuff. Then you can start looking at other systems and what parts may need replacing. Nice work.

[@raulguzman7945]

Man I got 2 sc’s as we’ll but there both 400’, a 92&97 , I need myself a 300 lol , my dream is to get a really low mile all original black or pearl white 2000 sc400 , I’m dying to feel that 3uz 🔥💯

[@Edward3jr]

Yeah man, I’m tempted to buy an sc430 next just for 3uz

[@Therealjusteast]

2:15 When you try to show an issue with your car to the boys

[@Edward3jr]

Story of my life 😂😂😂

[@skkrrtskrrt1470]

Don't speculate that's why it took awhile for you to figure out what was going on I'm going to say it easy was fine I believe your mechanic said it was okay that idle air control thing without it it'll make your car run like f****** s*** now that you have it running right disconnect the idle control thing and tried to drive it it's impossible the throttle body so big it needs air when that throttle body is closed that bypass is open I would say move on to something else maybe it'll make the thing run and ship better better running engine makes the transmission perform better well at least with my automatic I have GS300 IS300 but a Chevy truck would have that same kind of idle air control that one is as big as a cigar almost looks like a penis on a Chevy throttle body on that one is very large there is no bypass like that on the 300

[@xbugster]

Yeah, the ecu rebuilding requires to run the vehicle for just 2-3 minutes, then shut off, wait about 10 minutes and startup again, the ecu learns and balances, then runs smooth . No misfires, etc. Just rebuilt my ecu as well.

[@colenorthwick5023]

Does the sc400 & gs300 have same part compatability?

[@MRMAN-wb1tv]

*Who was the guy that fixed the ECU?*

[@Edward3jr]

Hit up Darryl Geller for all of your ecu repair needs. instagram.com/roadrunner4444/

[@carlazuz7704]

do you know what could cause bank 1 to misfire ive done all the basics like spark plugs and fuel injectors on that side o2 sensor and other stuff any ideas???

[@jeffmchenry6348]

I see vacuum problems everywhere. Tear it down and restore to stock and all this nonsense goes away.

[@craigkendell5706]

Hey man I really appreciate the vids keep up the awesome work ahaha I might need em for my sc400 build coming up cheers

[@Edward3jr]

Thank you!

[@skkrrtskrrt1470]

Adjust your throttle body listen to Phillips head screws and turn it backwards

[@skkrrtskrrt1470]

That is a bypass hose when did when the throttle body is closed that actuator is open open that car is only going to idle it's going to hesitate bad off the line why don't you use some of that black tape to reattach that hose we'll get a piece long enough new piece from the throttle body it's just big enough to fit inside that hole that's covered with tape try to point that hole towards the hose itself Dr PCP PCV tubing that almost looks like the whole size of a PCV valve too maybe you can get an elbow elbow in the hole piece of straight hose you shouldn't block that hose at all it needs to be utilized

[@skkrrtskrrt1470]

Hey man inside my engine bay that's where all my electrical stuff is I keep my duct tape in the trunk I hope you got the car cheap and I like the content it's a good color I hope you get the thing to be a daily driver

[@BAEZMAN]

Hey Eddy Mine has an issue now also has high rev misfire and car idle stays at 1500 rpms check engine comes on but when car is shut and turn the key all the way to check codes the check engine light dont come on. What you think that can be? 1995 SC300 5 Speed Factory

[@Edward3jr]

I’m really sorry you have to deal with this, it could be a couple of things causing this problem. Can you tell me what parts you have replaced? Have you inspected your iacv, maf?

[@BAEZMAN]

@@Edward3jr Just change the IAC and Clean the MAF

[@Chris-od1jp]

I would have thought the last owner turned the idle up as a way to try fix that starting/stalling issue. Then when you fixed some of those vacuum leaks the idle increased because you fixed the problem

[@Edward3jr]

It’s really weird, but it’s almost like it ran better with all that electric tape 😂😂😂

[@skkrrtskrrt1470]

How to use clear rubber tubing on my PCV lines they don't melt

[@TmP45]

Question, so if you replace the ecu on the car, will it still show the same mileage on the car or will it show the ecu you install mileage? Just curious

[@aaronhill3443]

Great work. My SC400 did the same thing. After recapping my ECU and redoing the plugs, leads and distributors caps and rotors it now idles and runs great. Also she needed a new PCV grommett. I also seafoamed her a lot lol. Edit: bro Im an electronics expert the electrlytic caps leaked its common replace them all

[@kurt8986]

u had a bad idle too?

[@aaronhill3443]

@@kurt8986 yeah it was bad learned a lot since I posted this just had to replace the plug wires again but the dizzy and ECU are fine

[@mightyeye4624]

Good content, I had this same issue with my sc4 due to a sloppy BFI install

[@Edward3jr]

Yeah, so many things sometimes it’s easy to make the problem seem bigger than it really is!

[@skkrrtskrrt1470]

You should look up the codes that are coming up on your ODB

[@lbtime07]

Great video I wish you did a video on a easy way to take the valve covers off the SC400. Im working on that now.

[@Edward3jr]

This will happen in the near future!

[@lbtime07]

@@Edward3jr thanks

[@skkrrtskrrt1470]

Those sensors may cross check the numbers look at the connector I see numbers on the side

[@samcrus7473]

Replaced my tps and my maf as well as a deep clean my iacv replaced spark plugs and I turned it on and went straight to 3100Rpms idle? I checked ecu and they are leaking but very unnoticed. Don’t think that’s my issue, any thoughts or ideas ?

[@OhMaccc]

Ever figure it out? I think my ecu caps are leaking I have a crazy high idle like that also

[@Klassyladyk]

I have 93 sc 300....when I bought the car it would die and as I drove it then it would idle really high then it just quit cranking. Then the now EX boyfriend put a fuel filter in it and it was driving good..one day drove it and ran it out of gas.......when he got back with it....it wouldn't crank anymore he never told me what happened.... I just had it fixed. The mechanic says it was ran hot and appear to have been driven really hard And may have blown head gasket or cracked head. It runs now but it runs really rough now... I have to let it warm up otherwise it will die....Im going to invest in it cause I love the hell outta that Car

[@Edward3jr]

I’m sorry to hear this, if it does have a blown head gasket it could be because it did over heat…

[@lbrb7152]

where do you get cold air intakes from for these cars

[@Edward3jr]

I modified an eBay one I used on my sc300. Check bay if you haven’t already.

[@patrickfyock7350]

Thanks my 95 is doing the same thing. Now I have a place to start

[@ivanstrickland7741]

Not for the faint of hart...but if you know rosin core solder is not put in chocolate chip cookies , then you may want to try some of these fixes on your on. If not, I would highly recommend you find some electronic smart guy and see if he can handle this for you. Techs who make wiring diagrams or schematics of what they are working on are very good to get to know and network out. Remember the older the vehicle (these cars are 20 and 30+ years old) wires, solder and components start to degrade very quickly. Enjoy: kzbin.info/www/bejne/paebeoSmg8qpm80

[@Edward3jr]

Thank you for sharing this! This is excellent advice!

[@JAYD3EChannel]

Does Darryl have another method to reach out for ecu repair aside from that instagram link? I think I may be starting to have issues with a car I just got though on the forum posts I've been finding someone either referenced eBay or said heres the link but I guess the response was so long ago the link doesn't appear.

[@Edward3jr]

Send me a message on ig, I think I can help you get in contact with him.

[@Yash-jo8hv]

Boss where are you

[@Edward3jr]

Been a while, but coming up on a lot of free time. Hoping to crank out a lot of of videos

[@rj015963]

Yoo clean car bro I love the gold! Also I need those rims 🥶 Man if you could help me out and see what part number on your tail lamp failure module.... I have same taillights and I keep buring through modules. All connections are good and using the bulbs that came with it, but I have 3 different modules and don't know which is the correct part number. Keep the content coming. 👌

[@Edward3jr]

Ryan I might be sell those wheels if you’re local to the dmv area let me know

[@predig1671]

Sc guy so I gotta subscribe.

[@ivanstrickland7741]

Bad Capacitor's are leaky, swollen on top of the caps. Also completely Exploded is a good indicator. A feeler gauge turned on its edge and layed on top of the cap will tell you if the top has swollen. If the feeler gauge rocks at all that is one bad cap.

[@Edward3jr]

Excellent recommendation! Thank you!

[@andrewpena758]

Hi! Hope you have a great Day! I have an SC400’92. I had issue with EGR VALVE. How do I address this. Some point it goes to safe mode and no power. I have the PCV and throttle switch replace what else’s can I do? Any help can do. Thanks more power

[@skkrrtskrrt1470]

Ghost in the machine

[@JohnnySoFresh143]

What about random sputter coming from driver side exhaust at idle?

[@Edward3jr]

I would need more information about this.

[@santotraficante8075]

Maybe you don't know anything of lexus

[@Edward3jr]

This is pretty spot on! 😞

[@Steavethefish3]

Please keep makin videos on the 400 the car community doesn’t really care for it so it’s scarce content on it 💯

[@Edward3jr]

Almost ready for the next one

[@sheldonwest7120]

Hey good afternoon I have a problem with my SC400 that I just bought for $800. I have a problem with it starting it have a brand new battery in it when I turn it on it just tumble tumble tumble until the battery almost to die I am smelling fuel in it but it just won't turn over any ideas

[@Edward3jr]

It could be several things. You may have to check ignition and see if you’re getting spark. If you are, then Check maf, tps, and look for vacuum leaks. Only other issue could be ECU

[@Edward3jr]

Honestly, I wish I can provide more help, but something like this involves trouble shooting

[@golemtheory2218]

Mate, who let you anywhere near the car's vitals?

[@Edward3jr]

Why do you ask?

[@nonamus9947]

Lol I just bought a 01' 1UZFE swapped IS300 yesterday

[@Edward3jr]

Wow! That sounds like a real fun car! Congrats!

[@nonamus9947]

@@Edward3jr thanks man, I’m planning to do an ar5 swap eventually

[@skkrrtskrrt1470]

You are a number one mechanic nobody will ever suspect idle air control or a hose or something unplugged it would have told you if you pulled out the codes

[@SpaceFoxAD]

So my car has kind of the opposite problem, it idles wayyy too low and is super shaky and likes to cut out every now and again. I don't doubt that the ECU needs a refresh, however I would like to give swapping out the IACV a shot beforehand. Maybe it'll be what I need, thanks for documenting your troubleshooting!

[@xavieuhr]

did you end up doing the clean? i have the same problem as you let me know how it worked out in the end

[@SpaceFoxAD]

@xavier I actually had to take a break from my SC and focus on my daily. I accidentally pelted a deer on my way to work lol. My poor ratty AW11 has to pull all of the weight now

[@xavieuhr]

@@SpaceFoxAD lol. just found out that it was the drivers side coil pack

[@ross3368]

@@xavieuhr having similar issues, what was your idle doing exactly?

[@GazaPerformanceGarageGPG]

Great Content Ed, that car is coming back strong 💪

[@Edward3jr]

Thank you bro! Thanks again for sending me those engine bay pics!

[@GazaPerformanceGarageGPG]

@@Edward3jr any time brother

[@senorpapas1479]

Where did you buy the idle air control

[@Edward3jr]

I went to the local pick and pull in bmore

[@KaiPonte]

This is cool to watch. I own two 400's - a daily driver '99 and a soon-to-be-modded '93. Can't wait to see what you did with the transmission. I am trying to decide between a KA24 (which I own) and a CD009. Keep the vids coming!

[@Edward3jr]

Will do!

[@Ang-el_D]

That car is in the right hands ...

[@Edward3jr]

Thank you!

[@dasasoul]

Can I ask what cold air intake you are using on your SC400?

[@Edward3jr]

Its literally an ebay sc300 cold air intake. I had it lying around and was able to make it work.

[@turbogears900]

Great job

[@Edward3jr]

Thank you!

[@shaughnmay7501]

What wheels are those man those are dope!

[@Edward3jr]

I have no idea, I want to say ebay but I have not been able to find them. I plan to take them off soon, and I’ll try to get a closer look at them.

[@MRMAN-wb1tv]

Knockoff BBS

[@mintyzee3000]

Sick

[@Edward3jr]

Thank you!

[@Edward3jr]

When are you swinging by to check it out? Could use a hand to drop the trans 😂😂🤣

[@diszruptiveent3634]

What driveshaft length did you use for the w58 to mate to the 1uz?

[@Edward3jr]

It looks like what was in there was a sc400 rear half to an sc300 front half. I never did get to confirm this though as I already sold it.

[@diszruptiveent3634]

@@Edward3jr damn u sold this thing huh. That info would be useful but ive never heard of combining half shafts. Do you think 2 piece driveshaft or full one piece custom is better?

[@Edward3jr]

@@diszruptiveent3634 2piece will save you money. For a custom one piece it can be 400-500 depending.

[@rustypotatos]

Yo cool odometer how is it so sick?

[@Edward3jr]

Previous owner probably used electrical tape for that too. 😂😂😂

[@rustypotatos]

@@Edward3jr yo do you know the drive wire cable will effect the idle as well tighten it or loosen it. That can help dial it in now. At least that works on my 1uzfe ls400. I’m pretty sure it works on my sc too but I haven’t had time to check

[@Edward3jr]

@@rustypotatos I have not tried adjusting the tps yet, but this is good to know. I’ll try this in the near future.

[@rustypotatos]

@@Edward3jr not just the tps but also the throttle kick down cable next to the transmission one

[@rustypotatos]

@@Edward3jr on the other side of the tps