I just got an 86 IROC. Drove it 90 miles home and thought it felt sluggish when compared to my 89 TBI car, at least off the line. Well I payed close attention when accelerating from a stop and it shifts at around 1500 rpms from first to second. I hit it hard (3/4 throttle) on a roll just after the shift and no downshift, but full throttle envoked a downshift. So I guess my two questions are, is there any way to get it to hold first longer without manual shifting? and does my tv cable need adjusting?

Also when cruising at 55, letting off the gas causes a "surging" like it has engine braking and then not, over and over until I slow down to 48, anything over 55 and the eingine slows it down like normal until 55, then the "surge" starts. you can even watch the rpms jump as the engine engages and disengages.

 

Definitely start with adjusting the TV cable. Checkout this page for instructions:
http://www.iroczone.com/techarttvadj.html

Someone on here reported theirs wouldn't click back as described when the engine was cold, so many try with it warmed up. Also, when you flip the throttle or the gas pedal to adjust the cable - push it HARD. Mine didn't adjust if you just casually push the pedal in it.

From there, you may need to adjust the cable in or out a little depending on where it ends up.

 

Ok, I havent done the adjustment yet but noticed another ailment today. At 50 mph a WOT push does not downshift to 2nd even in D. In OD it will downshift from 4th to 3rd, but not down to 2nd like previous cars Ive owned. The previous owner claimed a 350 was swapped into it and it has gobs of power so its not struggeling to accelerate, but I know that not downshifting is holding it back some.

 

Adjust the TV cable

 

Ok, checked the tv cable. The housing was all the way towards the firewall (ehich from what I have read, should make for firm shifts) Well the shifts are real soft, so just to see what happens, I moved the housing about half way forward (it wouldnt move at all with the ratchet using the throttle) and took it for a test drive. Absolutely the same results, no different. No matter how slow Im going, if it has upshifted to 2nd, it refuses to downshift until I stop completely. I did get two 40mph downshifts from 3rd to 2nd at WOT. Maybe I just need to think about a shift kit, both of my last cars had them and held 1st until 20mph regardless of partial throttle position (WOT would hold until redline) and would give a snap neck shift to 2nd.

 

If there is something wrong with your transmission, you need to fix it before putting in a shift kit.

Sounds like your TV still isn't adjusted properly. I drove around my neighborhood numerous times, stopping to adjust the TV cable until I found the right setting.

 

if the tv adj doesnt work, do you know if the car has had a rear gear swap? if so the trans could not be setup right for the different, probably lower gears amd that could cause that problem. sonnax makes this cool little spring thing that clips on the tv cable and corrects the problem, if that is the problem.

 

I thought that with such an extreme change in position, I would have noticed something different. Like I mentioned the cable was originally adjusted all the way "firm" and there was still a small bit of slack, perhaps the cable is stretched? I can pull on the cable and get a little more out of it while holding the throttle wide open.

 

sounds like a tv cable to me. you would be surprised (or maybe you wouldn't!) how much that can affect things.

brian

 

at wide open throttle you should'nt have any slack in the tv cable.

 

Ok after tinkering with the setting last night some mre I managed to get the cable further back. Its not perfectly set yet because it drops out of 4th a little too easy, but I can deal with it. Now I notice a new problem. At WOT it shudders at high rpms (4500 and up). It doenst do it in neutral so I dont think its engine related. It feels kinda like the shudder you get with a bad alignment, but stops just after the car shifts. Both 1st and 2nd have shown this same ailment (Im not going to try to test 3rd, that would be stupid)

Would too much pressure cause this, or does the trans need some major maintainence? I plan on having it flushed and filled with a new filter installed soon.

 

Sounds like the governor needs to be reworked. In the tail shaft of the trans there is a governor that controls shift timing also. different weights will change the timing of the shift.