Maybe someone has had this happen


New Member
and has a solution.

1990 LS400 all stock.
A while back when I started it, it ran great for 5 to 10 minutes, then it just died, started right back up and would run good only holding the throttle and maintaining over 1800 rpms or so. Let is cool down and did the same thing for many other trys. So put it on back burner to work on other projects.
Got a bit of time and had extra used parts so I replaced the airmeter, and idle control valve, it started right up after sitting for a fairly long time, and ran at about 1600 rpms and slowly kept climbing to about 2000 and leveled off there. If I slightly stomped the gas pedal the rpms would fall off to 600 or so then right back up. So you think I have a bad airmeter or idle control valve? Have others experienced this with bad ecu's? Thanks.

Oh and when the problem originally started it had an airmeter code, 27?? I for get. No codes now.


"Supra" Moderator
Staff member
I've seen something similar happen with the leaky capacitor problems of the 90's Toyota/Lexus ECU's.

Easiest thing to do is swap yours temporarily with a known good ECU if you can find one.

In what part of the world are you located? This is a very international forum, and we could probably help you more with a little more info about yourself.