For you Chevy guys, ive got an 85 Caprice Estate. Have had some trouble in the past with the Quadrajet and the Master control Solenoid, but last Friday I got that working correctly... well a Carb guy did. The cars been running in limp for over a year and shifting late, and the whole time i thougth it was because i had a heavy foot. NOW that the computer is operating, and the carb is operating as it should, The trans is shifting too early causing bad lugging. It shifts early at all shifts. Any ideas as to what i need to check next? Will a vaccum leak or bad modulator cause an early shift? What other ideas do yall have?
My 86 IROC w/ a 700R4 did that too. Something was wrong with my kickdown cable I believe, so in drive I'd be in 4th gear by 10mph. I ended up just ratchet shifting it every time I drove it.
The Kickdown cable is too long. The carb guy took it out of adjustment when he was messing with the carb. It needs to be tightened up. Super simple to adjust, just need to test drive it between adjustments.
Is there a vacuum modulator? If the carb, etc. is running better, then maybe the old vacuum modulator or just a leaky vacuum hose are not letting the trans engage properly at the shift points.
Sounds like ther TV (throttle valve) cable is out of adjustment (otherwise known as the kickdown cable). If you drive this for too long misadjusted,it can damage the transmission by overworking it at a lower rpm than specified. As others have said, an easy adjustment.... Look by the carburetor where the kickdown cable comes up....it will snap into a bracket and go to the carburetor linkage on the drivers side. Where it snaps into the bracket, it will have a larger housing....this housing that has a metal button to push in...if you look on the side that goes to the carb you'll notice teeth on the plastic area coming through the bracket. What you need is to do is push that metal button in, then push the toothed part back into that housing....when finished, let off the button, get in the car, and step the throttle all the way to the floor....that toothed part will move out by itself and be locked by the metal button. Sometimes it also works to have 2 people...one to push the button in and watch the cable, and the other to step on the throttle. When you get the initial setting, drive it and see how it shifts....you may find you need to adjust the cable one way or the other slightly...go back to the kickdown cable, hold the toothed part, push the button down, and SLIGHTLY move the toothed portion one way or the other....a little movement will make alot of difference. Ok...as if that didn't sound complex enough....lol Once you look back by the LR corner of the carb, you'll see what I'm talking about. There may be 2 or even 3 cables....one will be the throttle cable, and go into the firewall, one will be the kickdown, and go down the back of the motor to the trans, and the possible 3rd will be cruise control, which sould feed over to the drivers side fenderwell, if I remember right...
My caprice also have problems with the transmission and I think it's the modulator maybe you can give me a hint. When I drive on the highway and I have to climb hill ( man I'm bad in english, I wish you know what I mean) I push the engine a little harder to stay at the same speed and when I get to slow down and brake after driving the highway, at 20 or 30 km/h the rear wheels makes crunchy noise and the car vibrates a little. Then when I start accelerating again, it has almost no power at all, no torque. It gets normal after maybe 3 or 5 minutes. I think the modulator doesn't make the transmission shift down or something like that. Any ideas?
Your problem sounds bigger than that. If the brakes are affected, the power brake vacuum line or the brake booster are part of the problem. You have a major vacuum leak somewhere. Also, because Quebec uses a lot of roadsalt, you should check if your vacuum reservoir 'tank' is rusted out. If it was just the transmission modulator, your brakes would not be affected. You could buy a vacuum gauge and install it on the dash. Worth every penny. I posted a lot of information about vacuum gauges and what they tell you about the engine's operation in here. I suggest you have a look. It might save you a lot of time and help you solve this yourself (and save some money ) http://www.stationwagonforums.com/forums/showthread.php?t=4629 Joyeux Noel!
The car brakes really fine, its just when I get to 30 and or 20 km/h it starts vibratings..? I'Ll take a look at your post, and I'll go to the garage today to check this out, i'm changind my front shocks and coils today anyway.
The brake noise and vibrating might be caused by a lack of vacuum to the brake booster. At low speeds, when you accelorate, the engine reduces vacuum. When you slow down, vacuum goes up to normal values, except that the power brakes demand all they can get. It might just be a bad or dried out vacuum hose.
Strokercutlass knows what he's talking about. 700R4s and 200R4s do not use vacuum to shift the trans. It's all about the TV cable (throttle valve cable) on these transmissions, controls line pressure, shift points, shift firmness, and kick down.
After reading all that it reminded me of how it takes longer to explain a repair than to actually do it. I run into that all the time! G
