BK4293

Hey Guys and Gals,

I have a 1992 Lexus ES300 and it's idling very rough whether parked or in motion, Lots of hesitation when I try to accelerate all throughout the power band. Plugs and wires Have a few months on them, Fuel filter has a few weeks on it (Both changed before the problem appeared).

I drove around Sunday with no problems what so ever, Started her up Monday to drop the rugrats off at the baby-sitters and it was idling very rough. Today I changed the air filter (Looks like it wasn't seated right so I figured it could have been getting bad readings) sprayed the maf down with electrical part cleaner and replaced the cap and rotor while I was there but none of this seemed to help a bit.

FYI It was very very cold here in Chicago on Monday, but it doesn't seem to get any better once the car warms up. It doesn't die or surge, it just put puts along...

Do any of you experts have an idea as to what could be wrong with my baby???


Steve

BK4293

Codes are:
Code 24 Intake temperature sensor circuit fault
Code 25 Air fuel ratio fault

Code 52 and Code 55 Knock sensor circuit fault which have been there since I bought the car..... Just too lazy to chck out the harness I guess.....

BK4293

Anyone, I'd really hate to lose her, but the wifeys telling me it's time to stop putting money into the Lexus......

ZGadson

My quote from the hesitation thread - this could be causing your issue as well.

And that's a gorgeous ES. I traded my 92 in for an 02 Infiniti I35 and missed my Lexus.

BK4293

Thanks alot, she's really only that pretty on the internet though.....
I read your quote during my 5 million searches on this site....

I've been through a whole lot of stuff and I know I'll find the problem sooner or later, as I stated I had the airbox out to clean the maf and replace the cap and rotor, I was hoping I would have bumped something that would have magically fixed my ES, but I guess I just don't have that "Fonzie" touch... =)

ZGadson

lmao. Wouldn't surprise me if you saw my original post about my rough idle back when I actually owned my ES. That was probably 05-06ish that I had it. I'm still pissed that I traded her in.

BK4293

If I tell you secret, you promise not to post it on the internet????
I only paid $400 for that clunker, and have gotten every pennies worth out of it =)

It really is a nice car to get me back and fourth, I keep telling myself I'm going to mod it, then talk myself out of it.....

ZGadson

Find me an ES! haha

BK4293

This wouldn't cause my problem...... ya think?

BK4293

Any of the lines going to the IAC for antifreze?

BK4293

Does anyone think an o2 sensor would make a car have these symptoms?

BK4293

Well finally got around to replacing my broken IAC with another one I found on Craigslist for $55. While swapping the IAC I noticed that the throttle bottle bypass hose (The One That Goes From The Intake Accordion To The IAC) seemed to have oil coming out from the middle where the two pieces connect. So my guess is that was causing the hesitation. I put some gasket maker around the male part of where the hoses connect then replaced the handy dandy squeeze clamp with a tightening screw one and replaced the other two as well.
I know the IAC was broken, but I went over that thing with blue permatex twice and it never ran any different, so I know deep down in my heart that was the problem, but I guess I'll never be 100% sure....
So for you guys with hesitation issues that have searched far and wide for your solution, spend the $3 on a set of clamps and thank me if it works!

es300majr

i know this thread is OLD!!! but im having the same issue but my car dumps ****** loads of gas into the cylinders and just a bunch of white smoke from the exhaust n im getting codes 25 and 55

im to the point of breaking lol i want to fix this iisue

GS4_Fiend

iTrader: (22)

Code 25 - lean exhaust
Code 55 - knock sensor signal

Check for vacuum leaks. Test out ur VAF sensor (air flow meter). Get your knock sensor checked out

forwardnow

A mechanic turned me on to a hack for this issue: Disconnect the idle motor. If it idles fine after that, the idle motor needs to be replaced. If it still idles rough, it's something else.

I know it sounds a little counterintuitive, but my '92 continues to run fine.