1990 7mgte with only 120K miles on auto

MA70-3.0GT · 11-13-2009, 01:29 PM

Welcome to the forums. It's hard to diagnose something like this without actually seeing/hearing the car, perhaps you could post a video from a standing start accelerating moderately to say 45mph & then flooring it (going for kickdown)?

Not sure what you mean by a jerking sound either but from the fact you say the rpm's hardly rise I'd suspect a misfire, meaning it's more likely an engine running fault than a gearbox issue. Generally autobox problems seem to fall into one of two categories, slipping/loss of drive (symptoms, revs rise out of proportion to speed & don't drop when the box changes up. like a slipping clutch on a manual basically, or just no drive at all). The other usual autobox fault is jerky/sudden changes which can be caused by sticky valves or dirty fluid.

Like I say it's hard to diagnose without a video, but I doubt you have a gearbox problem from this post.

Cheers, Dan.

11-13-2009, 01:29 PM	#2
MA70-3.0GT 12psi boost Join Date: Oct 2009 Location: Crewe, England Posts: 356	Welcome to the forums. It's hard to diagnose something like this without actually seeing/hearing the car, perhaps you could post a video from a standing start accelerating moderately to say 45mph & then flooring it (going for kickdown)? Not sure what you mean by a jerking sound either but from the fact you say the rpm's hardly rise I'd suspect a misfire, meaning it's more likely an engine running fault than a gearbox issue. Generally autobox problems seem to fall into one of two categories, slipping/loss of drive (symptoms, revs rise out of proportion to speed & don't drop when the box changes up. like a slipping clutch on a manual basically, or just no drive at all). The other usual autobox fault is jerky/sudden changes which can be caused by sticky valves or dirty fluid. Like I say it's hard to diagnose without a video, but I doubt you have a gearbox problem from this post. Cheers, Dan. __________________ '89 MA70 Supra GT aero 3.0turbo JDM, Rebuilt motor, K&N intake, 3" stainless turbo-back. New turbo and braided line kit... '89 Honda NC27 400, NC23 cams, open pipe, PC36a shock & possibly Showa USD forks... '83 Yamaha 29R XJ750E-II, number 69 off the line, only runner in the country? Original except Koni shocks '95 Honda PC26 CB500R, Winter hack, hateful, trying to sell it I'm not paranoid, they really ARE after me!!! Last edited by MA70-3.0GT; 11-13-2009 at 01:32 PM.