Me and Friend are STUMPED

[Ne0z31]

Original Post

this is an issue that, apparently, no one in the supra world, or turbo world has heard of so far.. that i've run into at least.

My engine has no vacuum or oil leaks of any kind, whatsoever. everything is connected, and hooked up right. but when my TPS is plugged in, i can stand on the gas peddle, and it'll fuel cut at about 2500RPM, it'll climb, drop, climb, drop, etc etc without me letting off the gas at all.
me, and my shop have been trying to figure this mystery out for about a year now, so, if anyone has ANY advice on how to fix this problem, please, help me out

the list of things that have been replaced/installed trying to fix this:
HKS Fuel cut defencer
new, blow off valve (stocker leaked)
all new hoses and vacuum lines
new, tested ECU
and the TPS has been replaced 3 times, due to us thinking they might have given us a faulty one all 3 times.. but they all tested positive, yet, it still won't rev past 2500RPM unless it's unplugged

anyways, thanks in advance for any help

if anyone knows what could be wrong lemme know, he's been tackling this for months now...

btw, its a 1989 Supra with a t3/T4 hybrid turbo and some other work done

[Jeeves]

FCD's/MAF's can fail too, remember that rev limit could be MAF related and that the FCD taps into the MAF wires. I'd pull it out, see if the FC goes away, then if it doesn't swap MAF sensors with a buddy.

[SportTaco]

You sir are in limp mode... This is usually a result of the MAF sensor being bad, wired incorrectly or not plugged in... Dont ask me how I know...

Cheers-
Erich