So basically, when I bought this car 2 months ago or so, it had been sitting in a garage for over 8 years or something. It only has 106k kilometers, and it drove home from the dealer perfectly.

Well about 2 weeks or so after it started having Intermitten Hesitation issues where it the rpms would drop and it would almost stall but not quit when i gave it gas. Also after 40 minutes of driving or so, and the car sat for about an hr after driving, if you go to start it, it would get no spark. So basically when trying to start it while warm it wouldnt get a spark. Took it to garage guy said its the Crank position sensor.

Ordered one, replaced it, starts fine, still hesitates though. Ok, spray out maf sensor, check plugs, change oil, transmission fluid, all that, Nothing changed.

Ordered Another Fuel ECU. Now it drives perfectly, starts everytime. No Hesitation. Except now when in overdrive mode, it flashes on and off constantly, with no pauses and I get a red ECT and Electrical Transmission error Warning. Yet the car drives perfectly since switching out the ECU.

None of the warnings came up with the old ECU it only had hesitation issues, different ECU, drives perfect, but gives warnings...

Its such a Headache, I love the car but these problems are making me regret buying it and having it crap out within 3 months of owning. :/

Any insight would be thankful.

 

sc300 or 400 and year? you replaced the fuel ecu in the back of the car, or the main engine ecu by the passenger floor. I am thinking you are talking about the main engine ecu. you may not have gotten one from right year possibly, or something was disconnected in the process. what info do you have on the replacement ecu?

 

ahh srry for lack of info, my lexus is a 91 sc400 v8 air suspension with the Emv TV, Import from Japan.

Main Ecu on passenger side door.

As far as Buying the right one, It had the exact same product number and all the same numbers to go with it. Everything plugged in fine. Been driving it all day today and its perfect. except the error codes flashing. But it revs, and shifts gears fine Hmmm..ill check them both out and see if i can find any differences.

Also if the ECU I replaced it with is from a different year, would that cause any long term effects? or just cause it to throw errors?

 

erg...yeah just found out US sc400's are slightly different, the auto transmission has one extra solenoid I believe.

That being said, apparently it can run the car, and removes the 180k speed limit and increases rev 250 rpms. But the guy never said if it would cause any problems...

So what do i do, use it? and just tolerate the Error codes since it will in fact run it?

 

Bump

need to know if the the fact its an american ecu, and is running my import sc400 fine, just throwing codes, if its ok?