Lexus IS Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
11 Posts
Discussion Starter · #1 ·
new lexus owner. 2002 is300 5-speed.
Recently the car has developed a problem where (sorry im brand new to the lex/toyota world so ill speak in my honda roots terminology) where right around i think 35-4500rpm where the "Vtec" would be kicking in the engine bogs/ hesitsates really bad. If i stay in the rpms the problem seems to eventually clear out or if I let off for a split second then hit the throttle again it will take off like a rocket. The trac control is off when this is happening. Also it has a K&N intake system and hp catback
Also 2 weeks ago it threw a code for cyl. #1 misfire. the mechanic told me this was due to me fueling it with the car on and the cap off. The check engine light hasnt come on since.
Im thinking of starting with cleaning the MAF sensor and checking the plugs to see if they are lean, if so cleaning the injectors(although i have no idea how to do this)
anyone have any ideas or have experienced the same problem???? im not sure where to start. also if anyone has advice or a link on how to clean/remove injectors. thanks alot
 

·
Premium Member
Joined
·
27,116 Posts
Might as well start with the simplest things first. Check the condition of your MAF sensor... and clean it. Also... do you have a heat shield on your K&N intake? Are you seeing oil on the spark plugs?
 

·
Registered
Joined
·
5,155 Posts
I was getting a mid RPM hesitation, it was a dirty MAF sensor.

Grab some electronics cleaner, liquid based, from Radio Shack and some qtips and clean it, careful not to damage the wires that are inside it.
 

·
Premium Member
Joined
·
27,116 Posts
You may not need to use Q-Tips. I was able to spray the electronics cleaner on the MAF sensor... and the actual sensors inside came out really clean. Try that first... and then if it's still black... maybe then you can get more aggressive.
 

·
Registered
Joined
·
1,042 Posts
Yeah, sounds like a dirty maf issue. In case you didn't know, you need to clean the small wires/prongs inside the shaft of the maf. Not necessarily the sensor on the outside. Good luck.
 

·
Registered
Joined
·
11 Posts
Discussion Starter · #6 ·
thanks for all the info, yeah im going to go get the electronics cleaner right now and clean the maf. i found a good pictorial with directions so i see what 2 things to make sure are clean and how to do it. ill post if that was the problem or not.
 

·
Registered
Joined
·
381 Posts
If the MAF cleaning doesnt do anything maybe your O2 sensor maybe going out. Does your car smell like its burning rich?
 

·
Registered
Joined
·
11 Posts
Discussion Starter · #9 ·
any idea why i got a p0301 code then chinaman?
i cleaned the MAF and most the hesitation went away, it still feels weird tho.
 

·
Registered
Joined
·
346 Posts
To clean fuel injectors,you need to...
1) Go to Kragen or Autozone, and spend $6-$7 on fuel injection cleaner. The best brand would be "SeaFoam".
2) The directions are on the bottle, so that's where you go from there.

Level of Diffculty: 2/10
Tools needed: Pliers, only, to remove the clamp from the PVC pipe.

Any questions, let me know.
Planning to do a DIY on this i guess. I know this is something most people know how to do but there are some that do not.
 

·
Registered
Joined
·
11 Posts
Discussion Starter · #11 ·
yeah im not really familiar with using injector cleaner other than adding it to your gas tank, which seems to be a pretty weak way to clean the injectors i mean it takes me 2 weeks to go threw a tank of gas as is this car isnt my daily driver at the moment.
I have seen instructions on actually like running sea foam directly into your injectors without mixing with fuel but i cant seem to find this DIY write up anymore. if you anyone could link me or give me detailed instructions that would be great.
 

·
Registered
Joined
·
1,042 Posts
Seafoaming is fun :lol:

Read this thread seafoam
 

·
Registered
Joined
·
338 Posts
Pull the plug out, check the condition as opposed to the condition of a good plug. See if there's oil or antifreeze on it also check for abnormal color like extreme red, black, or white. Check compression. Then check for signal at the injector harness. Only 3 things will cause a p0301, too much/too little air, too much/too little fuel, or bad compression. You could have a faulty injector stayin open too long or too short or clogged, you could have no spark or weak spark, you can have a torn intake manifold gasket, or you can have bad comression. And pouring crap into the gas tank is the proper way to clean injectors. I am an ASE technician and that's how we do it at our shop, believe it or not it works. I have seen cars fail emission on the dyno, pour some of that crap into the tank and passes with flying colors, but don't ask me how it works cause it seems weak to me too but it works.

Get back to me and i'll try to help you out.

BUN
 

·
Registered
Joined
·
173 Posts
A quick and easy way to clean your whole fuel system... all you need is about 2 to 4 tablespoons of ATF in your gas tank when you fill up... I do this once a month an all of my vehicles and I've never had a problem. The detergents in the ATF clean out any carbon build upon the valves and in the injectors...
 

·
Registered
Joined
·
11 Posts
Discussion Starter · #15 ·
thanks for the info chinaman, if the problem persists im going to have to take it to a shop to get the compression tested. Im in the airforce and have limited tools. I guess id have the check the plugs too since that seems like a bit of a process on this engine taking the throttle body off, etc. Ill listen to the injectors with a long screw driver to see if i can hear them goin. I dont really imagine the car has a compression problem, the engine seems to have alot of power and respond very crisply(now), and it sounds like its in great condition you cant even hear the slightest valve tick/or knock.

I cleaned the MAF yesterday and put a bottle of injector cleaner and stp octane boost in, and reset the ECU. After i hooked it all back up i took it for a drive and most the hesitation seemed to be gone, i took it for about a 40min cruise down the highway to let the injector cleaner run through. Once i got back in town i really got into it and all the hesitiation seemed to be gone. I took it out later that night and checked for problems again and it ran great with no hesitation. guessing maybe a combo of dirty MAF/ semi clogged injector?
 

·
Registered
Joined
·
338 Posts
for a p0301 just pull the 1st and last plug out it's easier that way. I used to be army doesn't the AF have a craft shop? They have all the tools you need in there.

Holla at me if you need anything else, always willing to help a fellow service man man.

BUN
 

·
Registered
Joined
·
11 Posts
Discussion Starter · #17 ·
yeah they have an auto skills center its just easier to work at home yano, but yeah after reading all the advice im going to take it there and get into the engine ASAP which means probably sat. with my work/training schedule. The engine light came back on again, same code. cyl 1 misfire, along with the engine hesitation at mid RPM range so looks like its time to check the ignition/fuel components.

Chinaman i got your AIM but it seems like the email links dont work so if you wanna hit me up with yours my home email is [email protected] so if i have any questions before going to the auto shop this week we could discus them. I appriciate the help, ive had and still have a couple hondas and this lexus is really making me nervous so far compared to the maintenance/ problems(pretty much none) ive had with them.
 

·
Registered
Joined
·
4,895 Posts
My car was recently experiencing some of the same thing, and my first thought was a dirty MAF. I took it out, cleaned it, and took it for a drive. The hesitation went away a little bit, but then it came back so bad that the car would stumble terribly and threw a bunch of misfire codes. Finally took it into a local Toyota dealer (since I needed a loaner car) and they found that the Bosch spark plugs had basically eaten through the plug wires. The tech there told me that NGK stock plugs are the absolute best to use for the 2JZ-GE and that Bosch's are normally only good for euro cars. So you may want to check your plugs too!
 
1 - 19 of 19 Posts
Top