Detune Engine

J Mark Ford

New Member
Jun 13, 2013
I bought my GN new in Sept 87. With regrets, I sold it 10 years later to a doctor in Ft Meyers FL. I hunted him down and bought it back in 2012. He took excellent care of it. But he took the original engine and built it. Roller Rockers, HP Cam, bigger turbo, bigger intercooler, headers, flowmasters, etc. But he did keep all the original parts that came off the engine including the right angle air cleaner. I want to return the car to 100% stock. Can I keep the engine the way it is and just bolt on all the original parts? I even have the original exhaust from manifolds to the tips. Will the internal mods to the engine cause problems with the original equipment stuff?
I'd throw the original parts back on it. I assume you have the turbo, IC etc. You'll have to find out what the injector size is and get a matching chip from Eric at Turbotweak. Get the Flowmaster exhaust off. I doubt those are turbo mufflers.
Yep. Just undo what he did. As long as he has all the parts, it can be undone. Just time & labor. If you’re looking to keep it “100% stock” though, you’d have to change cam, roller rockers, converter, etc.

Stock versions of these cars are getting harder & harder to find. Just undo & like Scoob said get a new chip from Eric with all your info.
Spin the injector around...and you'll see a number on it. Look down the left side of the chart till you see the same number...and then look to the right...lbs/hr. That'll be your injector size for Eric.

He may have changed the torque convertor to match the newer turbo so it's prolly 'looser'...and it'll spin the stock turbo like no one's business. If he kept the stock convertor, you'll have to pull the trans and install it. You'll also have to find out if it's a LU or NLU convertor. If the trans was changed to a NLU configuration you'll have to have it changed back.