Is200 Problems After Replacing Throttle Body

[Slacker]

Hi guy's and gal's,

I am a bit of a newbie to the lexus scene and I was wondering if I could get a few pointers if poss please.

I have a 2000 IS200 auto, which suffered from rough idle, the EML and trc light came on, when I had a look at the engine and noticed that the throttle body was noisey and that the came gear attached to the throttle cam was kinda rattling. I operated it by hand a few times and then it suddenly stopped rattling and all was ok for a while but then same problem.

I decided to remove the throttle body and take a closer look. I removed the throttle body and removed the TPS sensor that relates to that particlur noisey cam...............couldn't see anything obvious. Put the whole thing together again and re-aligned the TPS sensoe which I removed earlier.

The problem I have now is that upon start up the car revved up high to around 3k or so, I turned it off, fired it up again and then all seemed ok............BUT....when i pressed the accelerator pedal there was nothing until I pressed tha pedal all the way to half way and beyond. It is like there is no response from the throttle pedal for the first half. I took a look at the throttle body and can see the pedal moving the throttle cable but no response from the engine until you press it beyond the half way point.......kinda like there is nothing on part throttle at all.

BUT.......alongside the cam where the throttle cable is attached to there is another cam attached to it (the one that was noisey to begin with) does not operated when the peddal is depressed........when turned by hand thoughm the engine responds but then dies after revved. Then upon firing the car up....the throttle pedal responds as it should do and the car revs just fine until you let the pedal go back to idle speed and then........nothing again.......no response until after the pedal is pressed passed half way or so.

Phew.......I hope all this makes sense! Anyone got any ideas what I have done wrong at all.............The codes come up as there is a fault with the TPS "A" sensor, which was not present before I messed around with it. checked the wiring and took it off and checked it again for the second time but all seems ok to me??!!

Any help would be much appreciated.

Many thanks

[Slacker]

Just to update,

I plugged in the scanner, erased all codes then fired the car up, drove it down the road and Error code P1125 came up.

I assume that this relates to the throttle motor.

Any ideas guy's,?

[lexynik]

click

[Slacker]

click

Ok, just to update;

I got a second hand throttle body, complete with sensor and motor. Installed it in the car and replaced all the gaskets..........also replaced all the injector seals aswell as they were pretty perished and could occasionally hear hissing from them when the injectors were moved.

Fired the car up (reset ECU)...............still got a fault code of P0171, all the other codes were gone though.

I rechecked gor air leaak and stuff and rechecked my work but all seemed ok.

The P0171 code is usually asscociated to the MAF or O2 senosors, is this correct. I cant see an MAF sensor on the lexus.

would you guy's say that I have an O2 sensor failure on bank 1?

Any help would be much appreciated.

Many thanks

[iano21]

well. .

i think its a map sensor not maf that is on that car. . it is right behind the throttle body. . maybe you pulled wire off it or the vacuum pipe came off when changing throttle body. it has vacuum sensor written on a sticker on the top of it. it is there just hard see just look over the throttle body and it is slightly to the left of it behind it.

[Slacker]

Further update:

After re-checking all my work and the Map sensor as another member mentioned - all seemed fine and everythig appeared as it should with nothing missing.

Still got the P0171 fault and also a P0302, which always present after resetting the ECU.

Funny thing is, I switched the coils from cylinder 1 and 2.............this time the misfire was in cylinder 1 P0301, this lead me to suspect the coil pack, so I bought a new genuine unit, reset the codes.................engine seemed sweet for the first few minutes upon starting but then the dreaded rough idle and the scanner still said P0302, misfire cylinder 2 ??!!!!!!!! and P0171.

Really am running out of ideas here, could it be the injector on 2 is also out??

cheerz.

[lexynik]

hiya-member jayson2223 had similar problems with various warnings and codes flashing up recently - turned out to be one coil pack and new spark plugs to fix the problems - he also replaced throttle body to no avail - id pull your spark plugs and check em just in case-his were visibly knackered

[iano21]

did you try pulling the connector off injector two too see if the engine ticking over changed that would tell you if the injector was the only fault on that cyclinder if it stays the same it is injector if it gets worse the injector is firing. .

[Slacker]

did you try pulling the connector off injector two too see if the engine ticking over changed that would tell you if the injector was the only fault on that cyclinder if it stays the same it is injector if it gets worse the injector is firing. .

cool. I will check this out and report back.

[mista_khan]

guys ive been told by the lpg guy, that I should change my spark plugs from iridiums to standard copper core plugs as they work better on lpg and also to make gap on plug around 0.66ml ,

can anyone tell me part numbers or plugs which will fit my lexus and are copper core standard ?

[istanbul05]

A similar thing like his happened to me last week when I cleaned my throttle body out because of low idle.

The idle went crazy and upto 3000rpm on cold start. After trying everything including resetting the ECU ..I tried one last thing which was adjusting bolts on the throttle cable to give a little more slack and BINGO idle now sits on 900rpm which for a auto I am told is acceptable.

[Foxmulder]

Hello.

I have an is 200 running on lpg,  have had the engine rebuild since the idle was so bad, like if it was running on 3 cylinders.

When the engine was opened ,  in cylinder numerb 2 there was a damaged exhaust valve, .

HAve replaced em all , new  ,  also new piston rings, and  cylinder hear overhauled.

The engine runs smooth on petrol and lpg, but there is a problem with the  throttle body, it kinda gets a fault when I give full throttle.

TRC light come blinking on as well as the engine light. Have tp turn the engine off restar it and be careful not to push the accelerator pedal  too much.

 Anyway problem is either on lpg or petrol. It is sad that after all the money I spent I still have a faulty car.

Have swapped the trottle body, and problem is the same...

Codes are:

P1128 :Throttle control, engine locking

 

P0120:circuit switch A sensor pedal / butterfly, malfunction

P0121:Switch circuit A sensor is pedal / butterfly position, field / performance problem accelerator pedal position sensor

 

any Ideas now?

Thanks

 

 

[Bluesman]

If the problem is the same whether you use LPG or petrol it has nothing to do with fuel other than getting it to the engine. What sort of outfit strips and rebuilds an engine and quite happy to let the customer running like a bag of nails?. Take it back to them and ask them to finish the job in a professional manner ie running nice and smoothly.

[ColinBarber]

Swapped the throttle body including the motor and throttle position sensor? If all of that has been replaced then possibly wiring damage or even ECU problem (but very unlikely).