Toyota Supra Forums! Join the Supra forum!

Toyota Supra Forums! Join the Supra forum! (http://www.toyota-supra.info/forums/)

- MKIII Supra (http://www.toyota-supra.info/forums/mkiii-supra/)

- - overboosting (http://www.toyota-supra.info/forums/mkiii-supra/16501-overboosting.html)

i have a 91 turbo supra (automatic transmission ),i need some advice.. my car is drivable, but when i hit the gas to pass someone or just because, the boost needle goes up to 15 psi (more less) on my aftermarket meter and the stock goes all the way to the top,, after that is total downhill cause the check engine light comes on (for a second or so) and i start to worry cause i dont want another bhg,, i think im experiencing fuel cut?.. what could be the reason for that boost pressure? i dont have any mods, only hks mushroom filter and hks ssqv bov and my exhaust has no catz just a muffler with a 4 inch tip. I want stock boost not this crazy thing,, could it be that my boost pressure sensor has gone bad? or my wastegate actuator? or the timing is off??... when idling it doesnt shake or knock nothing like that, the idle is perfect it sounds clean and deep... ANY ADVICE?

you should be hitting fuel cut earlier, IMO. You are overboosting, unlikely that two different gauges are both wrong and the ECU doesn't monitor boost pressure. check the error codes yet? I bet theres one for abnormal boost pressure. ;)

Check the waste gate, actuator and vacuum hoses.

Without a doubt, no cats and shimmed waste-gate will produce 15 psi resulting in fuel cut-out.

Quote:

Originally Posted by Bill UK (Post 80910)

Without a doubt, no cats and shimmed waste-gate will produce 15 psi resulting in fuel cut-out.

Who said anything about shimmed wastegate?

No one, but thought I'll mention it as mine did the same when I first bought my first Turbo Supra, just in case yours is shimmed. I ended up fitting the second cat back on.