lexfreak22

So i just purchased this sc not too long ago, when i got it, it was running really rich. Found out the 5v power wire to the maf wasnt in the ecu plug all the way, but anyways. Before fixing it and after my car has a weird stumbling issue on take off. Only when cold it gets worse the colder it is outside, but as soon as the car is at running temp it stops. Basically when i start it up and take off while letting out the clutch it just bogs way down then bucks back to life. I have the next couple days off work and am trying to corrrect the issue asap. Any help is appreciated.

Biddles

iTrader: (2)

Congrats on picking up an SC, any pics? Mileage?

ECU's can be problematic, especially if you have higher mileage. Driftmotion.com offers an ECU repair service, but your problem might be elsewhere. Have you done a tune up or anything to the car yet?

1JZPWRD

iTrader: (59)

I am going to move to proper section.

1JZPWRD

iTrader: (59)

Are there any check engine light on?

lexfreak22

I changed the spark plugs previous owner. Replaced the tps. He also replaced the ecu bought from a member here on club lexus. When cold it idle and then suddenly drops lower and then comes back up. Does it frequently until warm. Once warm it idles and runs completely fine without stumbling or anything.

As far as the car goes, i had been a lurker here for while i had been saving cash and saw my car on here. Its almost completely stock other than megan coilovers. Factory 5 speed with 228k. Other than the stumbling issue when cold the car runs great. The more suprising thing is everything works on the car including the a/c. I plan on 1jz swapping it around tax time.

zzobeyyzz

I'm going to be following this. I have the same issue tremendous loss of power when cold and power comes back when on running temp.

Ali SC3

iTrader: (10)

when you get that stumble when you tap the accelerator pedal before its warmed up that is the tps bad or not set properly 100%. since it was just replaced, it either was replaced with a bad one or was not set right for idle. try rotating it some to the left (counter clockwise) and see if that clears it up. it may stumble when you move it but it should clear up in a few seconds. go a hair over each time and test it out. there is a way to set it with feeler gauges and a volt meter but for the time being it should help.
If going counter clockwise makes it worse, then try going the other way till you find the sweet spot. it is usually somewhere between half way and fully clockwise.

lexfreak22

Thanks for the tip! Ill try it. The guy that i bought it off of did not seem very mechanically inclined.