I just put a Performer intake on my 91RS. I didn't get the rear 'china wall' sealed up good the 1st time, so I had to do it again last weekend. I also put on an open element air cleaner. Anyway, now the car doesn't seem to want to downshift right. Like I'll be going along in 2nd at 2000 RPM and floor it and it doesn't downshift. It sure seems like it used to. I searched the message boards and came up with maybe adjust the Throttle Valve (TV) cable. Hell, I don't know if my LO3 has a TV cable. It's got a throttle position sensor... What tells the engine to downshift? Any other ideas would be appreciated. Thanks-

 

Make sure that you reattached the throttle linkage on your TBI unit back on correctly. You may have to strech the bracket to get your throttle cable set correctly. Does your car idle higher? If it does your cable is being stretched and opening your throttle.

 

Most L03 cars have 3 cables attached to the throttle linkage.. throttle cable to pedal, cruise control, and transmission Throttle Valve.. the pedal and cruise cables attach to the upper side of the throttle lever, the TV cable attaches to the lower side... same goes for the position on the bracket.. TV is at the bottom.

TV also has a big D-shaped metal button on its housing at the bracket, though you might have to work to see it.. to adjust, press in that D shaped button till the adjuster slides back into the housing (You're going to have to press hard), hop into your car, floor it completely (not running), and you're set..

But, for the most part, in this case, make sure it's hooked up in the first place.

 

Right on. I know that I hooked those three cables back up. The new intake sits 1/2 inch higher than the old, so maybe the TV cable needs adjusted to compensate for that. I'll give it a try tomorrow and let you know if it works. Thanks. Auto tech is fun!?

 

Some of it may be due to a change in geometry between the throttle bracket and the tbi. Youd be surprised how sensitive the tv cable can be. If its off by a little bit, your trans (like mine) will be history. The way that works the best when you set the tv cable is to block the throttle fully open, hold the metal 'D' lever, and pull the tv cable housing toward the firewall like your life depends on it (well, almost... just make sure you dont break it). Release the 'D' and close the throttle. Get in and open the throttle all the way up and that will set the cable to where its supposed to be. I tried it the other way and it would come out too far and be way misadjusted.

Oh, and dont tinker with the cable after its set. Thats not a good idea, either.

 

I adjusted the TV cable just now. It was too loose, and tightening it up did the trick. The car shifts down totally great. BTW, the idle is ~700 warm in park. Just wanted to let you guys know that your advice helped. Problem solved.