Hi every one, having some issues with my GS300 2jzge car is miss firing started on a rainy day tried to dry everything off and see if it was sweet but no still bad . No codes no check lights nothing at all pulled plugs and they where black as ever and almost looked like they had never been changed.

Plugs holes were full of oil but i cleaned it all out before hand Replaced plugs and leads with new stuff and tested coil packs which came back saying they were fine. While i was in there i gave it a compression test just to be safe and they all came back fine with good readings.

Checked MAF with a multi meter and it came back as 3.289 ohms guide says for ambient temps of around 20 degrees it should read 2-3 ohms.

All 6 injectors have pulse i am quite lost on where to look next?

Any ideas? Have searched and searched but everyone else seems to at least get a missfire code or somthing like that mine has nothing.

Cheers any help appreciated

Here is a video of it tried my best to get the miss fire

http://https://www.youtube.com/watch?v=gTbEuNZSE6s&feature=youtu.be

 

I'm not sure thats a misfire. It sounds more like detonation. Possibly a valve issue.

 

hmm ok cheers for the reply will look into it, the tap tap noise at the start is coming from the inside the black box by the TPS

 

So does it start and shut off? or does it run rough?

 

AHH! Got it! I recognize that sound! With the car off, move the throttle body by hand by pulling and letting go (kinda snap it) over and over. When you do, see if thats the same tap. Not sure if its possible for the butterfly to be loose, but it may be a faulty throttle motor.

If its the same tap sound you hear. You need to inspect it. First thing would be to pull off the intake piping and taking a look in there and maybe use a long screwdriver or something to move the butterfly to see if theres any loose play. There shouldnt be any. Depending how mechanically inclined you are, you need to mess around with things to see whats causing it to pop like that. Might have to remove the motor itself and see if its still stiff. Also inspect the APPS and cable and make sure everything is tight.

The reason it sounds like its misfiring is because the butterfly is opening when its not supposed to and letting more air in at random intervals.

Now this is all based on if it is coming from where you said, it does very much sound like the butterfly doing its business in there


Now that I think about it, you could take off the intake hose, start the car and look inside the throttle body and see if the butterfly is flapping in there. You'll probably even hear it even louder. (dont run it too long with the intake off cause well the obvious, dont want any dirt going in there Just run it long enough to take a gander and a listen.


See I'm in a huge hurry right now and not thinking straight LoL Again, now that I think about it, you can probably remove the plug from the motor to stop the noise. If it stops, then you've at least located the problem. Its too possible that the TPS or APPS is sending mixed signals to the motor causing it to open and close. There are different ways to troubleshoot it. I can elaborate more later.

Again, this is all based on if it IS the TB issue, it does sound like it to me I'll be back tonight and chime in some more if no one else comes in. Good luck

 

Hi yes it runs but very rough can still drive it just doesn't sound right.


Mr Jokster thank you very much for your reply had a quick look by snapping the throttle and at the very end of the throttle movement it is making the exact same noise.I am reasonably mechanically minded but im used to RB engines (devil i know haha) I will pull of the intake hose and have look like you said and do the other checks, hopefully this is the issue.I will be at work in about an hour and a half so will know more then

Cheers!

 

Just had a better look and it definitely sounds like its coming from the throttle motor grabbed another quick vid with the intake pipe of an it got a lot louder.

http://www.youtube.com/watch?v=fZPTu...ature=youtu.be

 

I'm pretty certain its the motor, effer is like $300 bucks Again, it still could be a sensor sending bad signals. Look up the numbers you're supposed to get from the TPS and give it a check to make sure its sending the proper signals to the motor.

Now its just a guess, but you can do some playing around with the motor and find out if there are any mechanical failures. Take it off and see if you can move it by hand, it should be tight. Also, when removed and plugged in, have the car running and see if it's still twitching while in your hand, that might eliminate a motor problem and point fingers at the actual throttle body (not too sure how accurate this will be, its just a guess). Its hard to type all the little different things I would do, cause there are so many. At the very least, we know where its coming from .

Maybe when you remove the motor you'll find that how it connects to the butterfly, is busted. I believe there are 2 tabs that insert into the housing, the housing part I think may be plastic and it could be worn, or broken so the motor isnt sitting flush on the inserts. This is where the mechanical side of you needs to take charge. You say you're into RB's, well doesnt matter what engine you're in to, an engine is an engine (until you tune it of course) its all the same concept. Just get in there, get dirty and figure it out! I have faith in you brother

 

Yes have been looking at the prices haha. Will pull it off and have a look what its like in side. and yes indeed an engine is and engine to an extent, its all this electronic stuff im not a fan of hahaha hence why i stick to RBS will whip it off now and have a look deffinitely does not sound right sounds like something is loose in there.

Cheers for all your help mate.

 

So have looked further into this pulled throttle motor cover off and some one has been in here before and rounded 2 of 3 screws that hold the motor to the throttle body.

But motor is definitely not tight can move it very easily sounds like a bunch of coins in there haha, this part is proving hard to find over here in NZ so i am just going to replace the hole throttle body unit for a warrantied 2nd hand complete unit. hopefully this fixes the issue, will report back when i get my hands on the used unit and installed.

Thanks for all the help very much appreciated!