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Why You Really, Really Wanted a 700R4 with a TV Cable, NOT a 4l60/80e |
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| I am hoping you decided to NOT use an Astro with a newer 4l60e or 4l80e tranny, even
though I warned you, but lets assume you either just didn't listen, are a truly sick pup that likes abuse, or inherited
Great Uncle Harrys mint 93 Astro , a carbureted V8 for free,and a sack full of cash, can you
still have a transmission that shifts with a carbureted V-8 engine? And will
it be easy and cheap? Yes,and NO, and NO. But I will save you a lot of grief by telling you what I went through. The most expensive bit of misinformation I have ever been told is that the carbed engine will work with a newer tranny without a computer. |
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To Be Blunt. Bullshit. |
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| It won't, It can not,impossible, against the laws of physics,( and probably, nature,too) all of the shifting is done by the computer using info sent by the various components and sensors on the engine, without it the tranny has no instructions for shift points and road speed,or engine temp and rpm so it does very little. ( Sounds like my kid, sometimes) | |||
| There is
a way to make it work but it is not
cheap. TCI makes an aftermarket computer that will run the newer GM 4 speed autos, but it is pricey. You will need the TCU ( Transmission control unit), a Throttle position sensor ( TPS) to tell the puter what your throttle position is, and a TV cable bracket to give your throttle cable the correct geometry. |
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| If you buy it from the manufacturer ( TCI) the puter alone is around 850.00 ( Actually,
this price has gone down, it was around 1000.00 when I bought mine) The TPS is 260.00, and the TV bracket that mounts to your carb and holds your throttle cable is 30-33 bucks depending on whether you chose a Holley, Edelbrock, or a ( arrrgh) Quadrajet carb. Thank goodness for the internet as after I saw those prices ( and came to) I started searching for better ones and lo and behold, ended up back at Jeg's. Jegs wants around 660.00, 199.00, and 25.00, repectively, for the very same parts made by the same company.Still not cheap but over 250 bucks lighter then TCI wanted. |
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| Programming is simple and you can do some amazing things once you get the damn software to install and actually talk to your computer. Yes, you need a computer to load the software into so it can talk to the TCI puter. | |||
| I hate the system myself, for the price, it was the most difficult, frustrating, time-consuming , experience I have ever had. The techs at Jeg's were as helpful as they could be but they knew little about the product referred me to the manufacturer who seemed to know even less. TCI's counter/phone guys know little about the TCU and its components,, and what they do advise varies from person to person. The software has instructions on installing the wiring and programming the puter but it differs from the written manual that also comes in the box., if you want an additional 3 or 4 ( mostly wrong) ideas, call TCI. | |||
| I could not get my computer to talk to the TCI computer,nothing helped, not one person I spoke with at TCI had any useful ideas and I wasted weeks checking and rechecking connnections, spent hours on the phone to Jegs and TCI,used three different computers to try to communicate with the tranny unit to get the damn thing to shift and nothing worked. Returned the unit to Jegs, ( that meant uninstalling all the extensive wiring and controls) they kindly sent me all new, reinstalled the box and all the wiring again and got nothing but: "Error" "TCU Not Found" over and over again. | |||
| I maxed out my last charge card and bought a new laptop,nothing, no communication, no
programming, no van that shifted. Just about the time I was thinking the van was a good place for a bonfire I remembered
a machine I had built ( and retired) for my daughter years back, it was running Windows 98, what were the chances
it would work? It did, it talked to the TCI unit and allowed me to program the tranny. The frustrating part of this was not one of the idiots at TCI could suggest that, am I to believe every fool that bought their "state of the art" units had computers with obsolete software or that noone but me ever had this problem and solved it? |
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| A couple of more discouraging points on this system. The TCI puter needs to know your road speed, it obtains this from your tranny's VSS ( vehicle speed sensor) on your tailshaft. The problem is the plug they provide you with does not fit the plug hole in the tranny, nor does the wiring colorcode match the GM wire code, or any other damn color code I've ever seen.Anyone that has ever fried a 12 volt appliance wiring it reverse polarity knows what I'm talking about here, but now we are talking about over a grand in electronics, something you would rather not incinerate. | |||
| Tech support ( they need a new name, no Tech there, and damn little support) at TCI had no answers and the wave that the VSS puts out can not be detected with a meter, not even my Fluke, so determining polarity that way was out. I finally talked to a GM engineer, he told me the values were so low they could not fry anything, so it was a 50/50 chance as to which wire went to where, one way the puter gets info, the other, it doesn't. | |||
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Something that WILL fry the puter. The manual tells you to wire the torque convertor lockup wire on the TCI unit to the hot on your brake pedal switch, supposedly to let the computer know you are braking, and to tell it to unlock your torque convertor. The problem with that was looking at the block diagram in the manual it appeared to me that that would provide 12 volts up to the computer and 12 volts down to the tranny. No way I pictured that idea was going to control anything, |
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| However, I did picture an impending electrical fire, or at the very least, a very expensive paperweight in my future. I made over a dozen calls to tech support, they were again, about evenly divided, About half said Oh, No ! and the other half said Go for It! | |||
| I finally insisted on speaking with someone with a better grounding in electronics then my dog and ended up talking to one of their engineers. He agreed that 12 volts had no place in that circuit, and informed me that once upon a time that circuit was used, but the new puters used throttle release to tell the convertor to unlock. Gee, I wonder why that info was still in there,could it be because the manual was printed in 1994 yet the ID tag on the puter said it was manufactured in 2005? | |||
| In closing, use a machine running Windows 98 as Xp does not work, ignore the instructions to hook voltage where it does not belong, and use trial and error on your speed sensor hookup, hey,you have a one in two chance of getting it right the first time. | |||
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