scioni16

Hey guys I'm new to club Lexus, also this car is my first car. But for a long time it seems that my car bogs when I'm accelerating from a complete stop. Im thinking about getting the spark plugs replaced, I would do them myself but since I'm only 17 I'm not about to try to remove the throttle body myself and put it all back together. Also when I'm giving it gas to accelerate, if I do not give it more gas when it begins to bog, it will continue to bog even more then sometimes even sound like it backfires. Also when I'm traveling at my usual cruising speed and I come to a hard stop or a rapid stop the rpm's drop low and the car begins to vibrate. I've looked for threads with similar problems to mine and the only thing I've come close to is someone having this problem with a 98 gs4 with coil and what sounds like injection problems. Any help or thoughts would be greatly appreciated!!

P.s. also the car seems to have trouble shifting gears if it passes 4000 rpm when I'm giving it a decent amount of gas. Could replacing the tranny fluid help? Also the car has 186,xxx miles and has had the tranny replaced. Finally should I look into getting the throttle body, and injectors cleaned and the spark plugs done?

Thanks
-Justin

Mcon

iTrader: (1)

scion16,
First, welcome to the club and sorry for jump in your thread, because this to issue start happen to me a few week already.

Secound, you say this; Also when I'm giving it gas to accelerate, if I do not give it more gas when it begins to bog, it will continue to bog even more then sometimes even sound like it backfires.
And this; also the car seems to have trouble shifting gears if it passes 4000 rpm when I'm giving it a decent amount of gas. Could replacing the tranny fluid?

I really want to know more about this 2 issue that are you have it right now, because I'm beginning to experiece the same thing in my car, like I said before. No matter what that only several months I will change all 3 coils, spark plugs, spark wires, with all originals parts. It is rather rare that feeling when you're driving the car? But as I said before, the car doing that occasionally??? I hope and someone have the correct answer for us.

Champers

Yep just jumped in the same boat myself. I've changed the spark plugs, and still going. That injector idea could be something too. My car has 230,000kms and I don't think they would have been changed.

77i9

iTrader: (14)

do the easy ones first
replace the plugs then the coils

scioni16

The car does it when I'm accelerating from either a cruising speed or while I am accelerating from a complete stop all the time sometimes it wont when the car isn't completely stopped, I've only really noticed it getting worse because since I have had the car there always was a dead spot in the gas pedal where you would begin to give it gas the car would do nothing, then as you gave it more the car would jump and then suddenly start to accelerate. Also it does this now. I'm thinking it could also maybe be something with the fuel pump because I filled it up today and it seemed to be less severe because when I filled it up the gas light was on the the tank was almost empty, but I do not do that regularly. Also maybe something with the transmission? like the clutch disengaging issue? I'm not sure. Also the feeling isn't rare it happens almost all the time when I'm coming from a complete stop, and occasionally when I'm falling below cruising speed and I give it gas to get up to speed and the Rpm's are low it will do the same thing. Hopefully someone knows the answer to this because all I've learned so far is that someone said they tuned it or just like I said cleaned the injectors, throttle body, and had the spark plugs replaced and they said it ran like new. Finally try to drive the car in manual mode and see if it doesn't, I haven't seen it do it while its in manual mode which is another reason why it leads me to thinking its a tranny problem. I asked a trusted mechanic of mine and he said it sounds like ignition troubles which makes sense. With the transmission it will be when I'm accelerating rapidy or just going through the gears quickly it will be smooth till about 4k rpm then start to almost lag.

Gdwrench35

Do you have a check engine light on? If so you should start there before replacing anything.

How many miles are on the car?

Have you checked your transmission fluid level and condition? Smell it. The smell of good trans fluid reminds me of sweet vinegar If it smells burnt then you should service the transmission.

It would be helpful to know the service history as well.

If you have ignition issues (coils, spark plugs, etc) they can make your transmission shift funny. As long as your fluid isn't burnt, then I would chase the running issue first.

Checking the codes is key.

clintdaddy

maybe try using Seafoam spray first. cheap potential fix, and will clean up your car even if it will not remedy your problem!

77i9

iTrader: (14)

Ok, let me elaborate on this.
A while back my Aristo had all the symptoms that you mentioned. First thing I did was replace the MAF sensor (had the same issue with my Cedric and MAF sensor was the culprit). Still had the same problem so I replaced the spark plugs. The problem persisted, so I replaced the coil packs. Problem fixed!
Don't overthink the problem when you haven't done anything yet.

Gdwrench35

After 25 + years in the automotive industry, I can promise you that sea foam does NOT work. That video is BS. It does do a great job of destroying your catalytic converters and O2 sensors though.

You also shouldn't guess at the problem and throw parts at it. That gets expensive quick. For what a MAF sensor cost, you could have paid someone to properly diagnose it and fix it yourself cheaper.

Mcon

iTrader: (1)

This is my next step to do. Buy a new MAF Sensor to see what happen. Because like I said before, I change all 3 Coil packs, Spark Plugs, Spark Wires and when I did it, I also clean the MAF Sensor with carburator cleaner
when I installing all this and I think I have destroyed as MAF Sensor works properly. Again, I think.

Gdwrench35

If you cleaned your MAF with carb cleaner, then you need a new one. Use specific MAF cleaner. Carb cleaner destroys the coatings on the filaments in the MAF. A faulty MAF can cause symptoms exactly as you describe.

scioni16

So I tried cleaning the MAF sensor and it helped the problem a little bit I only drove around the neighborhood so I wont find out until Monday when I drive more. Also the car is not throwing any error codes at all, nor did the MAF sensor seem that dirty the restrictors didn't seem too dirty to me compared to the ones in the how to videos I've seen. Next in response to Gdwrench35 questions, the car car 186,xxx miles. I do not know the full service history I just got the car around last February so I haven't even had it for a full year. I checked the transmission fluid and it smelt of sweet vinegar and it didn't smell burnt to me. Also the car has lost power since I've first got it, so that doesn't help with the problem what so ever. I think I am going to try and have the throttle body, and injectors cleaned, and also have the spark plugs replaced. I want to start with those because I know then that if the problem still isn't fixed after that the coils may be bad.

Mcon

iTrader: (1)

Gdwrench35,

Thanks for the info. I want to order my new MAF right now. That maybe is my problems for long time. . Thanks again

bruceb58

SeaFoam is the worst thing you can do to your car. Ruins your O2 sensors.

Mcon

iTrader: (1)

Update from me.

Today, I install the new MAF, reset the ecu just in case the ecu have some bad cel on it. I start driving the car to work and is GREAT. My problem with the 4,000 rpm and backfires go away. I push the gas a few time more the 100 mph and one time to 115 mph, no problem with rpm or missfire. Also, no CEL come on the cluster. I feel again the 2JZ power engine, when push me to the back of the seat. Heyyyyyyyyyyyyyyyyyyyy. So, for like year in half, I was feel the problem and all the time was the MAF. I so happy