hobojoe

Hey all so ive been searching and searching but can't seem to find any answers or ideas about my problem.



After running the car for a period ie at least 30 minutes i slow down and the idle just starts to go low like usually its at 600rpms. It dips at low as 150 to 300rpms. Then when i step on the gas to go again you feel the motor bog down just trying to go....then it either just kicks up and goes without a probem or just up and dies.....no lights to warn you or anything . Im at a loss as to what it could be....



Any help would be amazing!..yes i know ive posted close to something like this before but 1 got no answers and 2 now its happening more

JimsGX

Check out this link and see if this problem is the same as yours. How much fuel is in your tank when the problem happens? If it is similar to your problem, you're not alone but I haven't seen a definitive fix for it yet.

https://www.clublexus.com/forums/ls4...-hot-days.html

JimsGX

Hey Hobojoe,

Just realized you were part of that other thread... Sorry bout that. I've been trying stupid/simple things. The latest is to replace the rubber gasket on the gas cap. I keep the tank topped off so even in the recent high temp here of 95 degrees, I haven't had the problem reoccur (knock on wood!).

python

iTrader: (4)

it has to be an air/fuel problem...

j stuff

iTrader: (5)

i think i felt this once before... i just turned the ac on full blast and it helped hahah

vaughn37

my car idles at about 250rpm and it idles fine......anything lower and it starts to hesitate.
600 rpms is about what you should be reading at idle in park. the manual says 650 to 700

you can try to adjust your idle up..it is the round black piece on the side of your intake
a little adjustment on it goes a long way.

also check for any vacuum leaks ,cracked hoses etc

JimsGX

Since I cleaned my MAF this spring it hasn't happened again...

PureDrifter

iTrader: (10)

you mean your AFM right...lol

JimsGX

Yeah, yeah... I've always called them MAF for Mass Air Flow Sensor

hobojoe

Jim gas wise its happend with 3/4's of a tank down to just above empty.....where did you get the gasket and ill pull apart the afm this weekend to clean it any reccos on cleaning methods for it?

JimsGX

Bought a can of CRC Mass Air Flow Sensor Cleaner (MAF, PD!) at Autozone. IIRC, just a couple of 10mm bolts, a hose clamp, electrical connector and the air filter strap to undo to take the unit out. I just cleaned the fine honeycomb screen thouroughly from both sides and let it air dry for about a half hour before putting it back in. Can states not to touch the honeycomb with your hands. Visually, it didn't look dirty at all, but the acceleration afterwards was improved. I also reset the ECM/ECU at the same time by disconnecting the battery (can just pull the 20amp fuse unstead).

Even after letting it air dry for quite awhile, when I started the car, it ran like crap for 5~10 minutes and the check engine light stayed on. Kept giving it some gas until it smoothed out. After it smoothed out I took it for a ride and it ran well with improved acceleration. The check engine light went out after maybe 20 minutes or so.

You can get the gas cap gasket at either a Toyota or a Lexus dealer. The Toyota part number is 77316-16010. Runs about $12~$14... I put a little tube silicone lube on the gasket.

Let us know how it works out...