Is200 Power Loss

[sxe10]

Hi,

I bought an is200 6weeks ago and was very happy until a few weeks later it lost power.

The car first lost the top end kick, then a week or 2 later it lost some of the midrange, it runs perfect no misfire, noises or anything (only slight bussing noise out of the throttle body when the ignition is on, is this normal?), theres no lights on the dash and it starts fine.

I am a mechanic myself and have tried almost everything including;

spark plugs,

i cleaned the air filter,

asis manifold valve is opening,

cleaned throttle body,

the throttle body is opening fully with the pedal to the floor,

vvti solenoid is working and cam gear,

i took out the 2 front lamda sensors and drove the car to see if the exhaust was blocked,

i reset the ecu,

i checked the petrol flow in the fuel line,

does anybody know the voltages that would be going to the vvti solenoid? ive checked this at tick over and they seem very low at around 0.25 volts

does anyone have any idea what it could be because im out of ideas

[clifton 94]

hi have you checked the cam timing as it may have jumped a tooth i am a mechanic also and i no how frustrating fault finding is

[matt-c]

Mine was exactly the same. It was just lacking, like a derv turbo that had it's boost turned right down! Like yours, it ran fine, with no misfires, no warning lights etc. Then all of a sudden, it came back all by itself. I took it to Tesco, was slow. Then onto the hand carwash, was slow. Then upon leaving the carwash it was like a different car! Much more repsonsive, and much much quicker (well, quicker at least in relevance to the IS200 engine, haha)

The only thing I noticed with mine, was the throttle pedal felt stiff when it was running slow. When it went back t performing as it should, the pedal felt much lighter.

[ColinBarber]

The only thing I noticed with mine, was the throttle pedal felt stiff when it was running slow. When it went back t performing as it should, the pedal felt much lighter.

sounds like an issue with the electronic throttle not working. The mechanical throttle cable / butterfly is stiffer in operation.

[sxe10]

Thanks for the quick replies,

@clifton 94 Good suggestion but i forgot to mention i have already checked the cam timing.

@matt-c thanks for the reply matt , i sounds exaclty like you described except my pedal dosent feel any stiffer.

Could some one check one thing on there car for me, if you turn the ignition on in my car and press the accelerator you can hear a bussing sound coming from the throttle body and then when you turn the ignition off again you can hear a little ratling sound coming from the trottle body, i just want to know if this is normal?

I think maybe the next step is to try a new throttle body

[sjrainsford]

Yeah, mine makes quite a few little sounds with ignition on, then after I turn it off.

[sxe10]

@sjrainsford ok thanks for checking, ill leave the throttle body alone then.

I know theres no CEL on but i did a diagnostic check on it anyway, with the car at idle these are some of the readings that came up;

engine load percentage 34.5%

map 33kPa

long term fuel trim sensor 1 0.8%

long term fuel trim sensor 2 3.1%

RPM 650

Intake air temp 33 deg C

Spark advance 7.5 to 9.5 deg

does any of this seem wrong to anyone? the spark advance maybe? and engine load?

[LexIS200Sport]

Are your emission readings still within spec?

Will double-check my throttle body for noise on my way out this morning.

[ColinBarber]

does any of this seem wrong to anyone? the spark advance maybe? and engine load?

they all are within normal limits

[niko56]

I am having the same problem, found a solution in the end?