Take it back and tell them what's up. It shouldn't take long to adjust the TV cable.
86 tune ?
Thread Starter
Drifting
Joined: Feb 2009
Posts: 1,302
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From: colchester CT
86 tune ?
I just took my 86 in to a corvette shop to have it tuned up. I have owned it for 2 years, it ran pretty good but developed a high idle, 1000k. I had cleaned TB and replaced IAC but it did not fix it. I had the garage put in new coil, cap, rotor, set timing, and TPS and idle adjust screw. I got it back and it now idles at 5ook. runs good but it seems to shift differently. It won't go into overdrive. I am at 3oook rpms while doing 70mph. It doesn't always shift from 1st to 2nd really smooth either. it seems to stay in 1st a lot longer(higher rpms) than before. The mechanic said he adjusted timing to 7, the tps to .54 volts, and he said the idle screw was still plugged which indicated it had never been touched. These guys have a great rep and I am not a mechanic so I don't know if it is now driving correctly or not. It seemed to me that prior to the tune up it shifted more smoothly and I know the rpms were much lower at highway speeds than they are now. I am bringing it back in but I was hoping for some input here. The mpg also dropped from 17 to 15. I put about 200 miles on it since the tune up. any opinions would be appreciated as I really don't know much about working on the engine. Thanks guys
Race Director
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Kinda makes me wonder if the TV (aka detent) cable got out of adjustment. Not getting into OD would definitely lower your mpg.
Thread Starter
Drifting
Joined: Feb 2009
Posts: 1,302
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From: colchester CT
taking it back on thursday. usual paranoia of having just got work done and now something is wrong. I did not know if the problems could be caused by the things that were fixed and wanted a little education before going back there. He suggested the same thing, TV cable. I just don't get how it goes to the shop working fine and comes home with a problem. I am confident that it is a trustworthy shop so we'll see what happens. Thanks
Thread Starter
Drifting
Joined: Feb 2009
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From: colchester CT
just so I know, are shift points based on rpms or from other info from ecm. Just wanting to understand how TV cable works, how it's adjusted and what you base the adjustment on. Right now it seems like the car stays in 1st way too long and as I mentioned, it won't go into overdrive. also 2nd to 3rd feels slow and sluggish where it used to hit with some pop to it. again, these problems came after the tune up so I just don't know why. Is it time to save for a trans? Thanks
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The TV Cable is used to control many tranny functions such as shift points, line pressure, part throttle and detent downshifts. If it isn’t adjusted properly, you tranny will shift poorly.
I would think it’s possible to “bump” the TV cable while adjusting the TPS and throw things off, so it’s likely it wasn’t intentional on the part of your shop. They should be able to adjust the cable without a problem.
Let us know how it goes.
I would think it’s possible to “bump” the TV cable while adjusting the TPS and throw things off, so it’s likely it wasn’t intentional on the part of your shop. They should be able to adjust the cable without a problem.
Let us know how it goes.
Racer
Joined: Jul 2010
Posts: 308
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From: Kansas City MO
IF they removed the throttle body to clean it completely then they removed the TV cable which they probably "re-adjusted" without a pressure gauge attached to the tranny and just did it tight to "make sure" the tranny didn't burn up...
I would ask them what the procedure is to adjust the TV cable and if it does NOT include threading a pressure gauge into the transmission then it's just going to be a guess - you can get it close most of the time with experience, but to get it "spot on" then go to a specialty trans shop as they will have the pressure gauge to properly adjust it.
I would ask them what the procedure is to adjust the TV cable and if it does NOT include threading a pressure gauge into the transmission then it's just going to be a guess - you can get it close most of the time with experience, but to get it "spot on" then go to a specialty trans shop as they will have the pressure gauge to properly adjust it.
Team Owner
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Maybe when I'm too old to pickup a wrench, things will be different.
Until then, I'm the guy who is to blame.
Adjusting the cable is a snap.
Press and hold the button in to release the "tension"
Then get in behind the wheel and mash the throttle to the floor
You should hear the TV adjuster start clicking as the throttle is fully open.
Thats it!
Last edited by JrRifleCoach; Aug 11, 2010 at 02:46 AM.
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Thread Starter
Drifting
Joined: Feb 2009
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From: colchester CT
I was able to do all the front and rear suspension and ujoints, wheel bearings, brakes, radiator, new steering rack. I just don't know much about engines or testing for ohms and voltage so I thought it was a good idea to get it properly tuned up and go from there. Thanks for all the advice guys and I will let you all know the results. I was out on the highway today and was all the way up to 90 mph and almost 4k rpms and it would not shift to od which I guess would explain the nearly 2 mpg lost in fuel. I am afraid I might damage something so I am bringing it back in. A glutton for punishment I guess but so far I have re-done the whole car myself. Just have not touched the engine other than plugs and plug wires. It has about 84k miles on it so hopefully no major issues
Racer
Joined: Jul 2010
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From: Kansas City MO
OH - and the 700R4 transmission in there is NOT computer controlled - the only thing that is controlled by the computer is the lockup clutch in the transmission - but you should feel the 4th gear (OD) shift and not the slight RPM drop that occurs after the shift - it will run maybe 300 RPM higher than normal.
Have you checked the fluid level of the transmission (warm, running, in neutral)?
Have you checked the fluid level of the transmission (warm, running, in neutral)?
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Le Mans Master
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Just a quick test. drive the car, get it in 4th, and lightly press on the brake pedal. when the stop lights go on (look at your volt meter for a change, then return of volts) your torque converter should unlock. the RPMs should change. if it doesn't, the torque converter isn't locked up.
If it isn't locked up, it will be like losing 4th gear.
Make sure the problem is either the TCC or 4th.
Then do Rifle coach's fix.
If it isn't locked up, it will be like losing 4th gear.
Make sure the problem is either the TCC or 4th.
Then do Rifle coach's fix.
Pro
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If you can turn the key in the ignition, know how to open the hood, then (like me) you can do the TV cable as well, no pressure gauge needed, just JrRifleCoach instruction.
I would suggest buying a FSM (if you don´t already have it), interesting reading, and you get more familiar with your car, and...
Lot´s of other stuffffff
I would suggest buying a FSM (if you don´t already have it), interesting reading, and you get more familiar with your car, and...
Lot´s of other stuffffff
Thread Starter
Drifting
Joined: Feb 2009
Posts: 1,302
Likes: 2
From: colchester CT
tv cable has been adjusted and I still have the shifting problems. It will not go into overdrive. It stays in 3rd. I took it up to 85mph and it was at 5k rpms. 2nd to 3rd is very sluggish and has a slight hesitation. The mechanic now feels this is a trans problem so I am taking it to a trans shop on monday. What I don't understand is that the car shifted properly prior to the tune up work that was done. I started a new thread for the trans problem hoping to get some feedback before bringing it in. Thank you all for the advice, I really appreciate it. Helps to feel a bit more comfortable when bringing it to get work done when I have some good info from all of you.
Thread Starter
Drifting
Joined: Feb 2009
Posts: 1,302
Likes: 2
From: colchester CT
no they didn't do any thing to the cooling system. Still seems to get up to the usual temp, around 198 to 210 depending on how I am driving. Fan comes on as well so it seems to be fine in the dept.thanks for the advice.
