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Old 11-16-2005, 09:13 PM   #1
jermasaurus
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Computer in my 85 (Questions)

Hey, I believe the computer in my 85 basicly retards the advance when a knock is sensed. My truck originally had a 305 with the non-feedback quadrajet. The wiring has been removed for a while now since I installed an intake and carb. I haven't been running the vacuum advance either.

I went to hook the vacuum advance up again, and it spark knocks like crazy when you rev it a little. I tried ported and non ported sources, and set the base timing back to 4 degrees, but still knocks.
So i guess I need to hook the computer back up. I have the wiring around still.

My question is, can anyone tell me what all needs to be hooked up for the computer to retard the ignition properly? I am thinking maybe just the knock sensor and the wire(s) going to the distributor. I can't remember what the other ones went to, and I think one may not have been plugged in when I got the truck.
Any suggestions?
-Jeremy
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Old 11-16-2005, 09:57 PM   #2
86swb
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Re: Computer in my 85 (Questions)

I did not think the '85's had a computer? Is this something that someone added to your truck?
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Old 11-17-2005, 12:44 AM   #3
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Re: Computer in my 85 (Questions)

Not so much a computer, just a contraption behind the glovebox. It's original. I have seen it mentioned here before and I am pretty sure people agreed all it does is retard timing or somthing.
-Jeremy
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Old 11-17-2005, 01:27 AM   #4
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Re: Computer in my 85 (Questions)

It is the ESC computer. I think Federal ESC trucks have a 4 pin connecto to the distributor, knock sensor, and power. Someone correct me if I am wrong. Of course I have the full blown computer which is a whole other animal.
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Old 11-17-2005, 02:57 PM   #5
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Re: Computer in my 85 (Questions)

It is the ESC, you can bypass it and run a normal HEI:

http://www.73-87.com/7387garage/drivetrain/escrepl.htm
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Old 11-17-2005, 03:22 PM   #6
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Re: Computer in my 85 (Questions)

I wonder if my 86 4x4 has it?

Alot of thing underhood unhooked and some I found the other day underneath.
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Old 11-17-2005, 03:27 PM   #7
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Re: Computer in my 85 (Questions)

Quote:
Originally Posted by benoit454
I wonder if my 86 4x4 has it?

Alot of thing underhood unhooked and some I found the other day underneath.
It will most likely have it.
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Old 11-17-2005, 03:31 PM   #8
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Re: Computer in my 85 (Questions)

Quote:
Originally Posted by benoit454
I wonder if my 86 4x4 has it?

Alot of thing underhood unhooked and some I found the other day underneath.
It should have it. It's not bad to have one in operating condition for a cruiser but like the tech artical mentions most quit working a long time ago.
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Old 11-17-2005, 05:48 PM   #9
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Re: Computer in my 85 (Questions)

LOL I'd say so the other thing that gets me is it has the 700r4 which I know is electronic lock up TC. I am wondering if it's working or not because this thing has almost no power, new cam, lifters, headers, and runs good and once the truck gets going it rolls fine but getting it started really sucks. It starts up great and real quick so I know it's in timing right(need to put a light on it though for sure) but from take off is when it sucks. But it's got I dunno what gears and 33x12.50's now. Factory ditributor as far as I know, suposed rebuild in 96 but doesn't seem that way, had leaking broken valve cover gaskets, broke and leaking oil pan gasket, and fuel pump gasket was leaking, but on tear down it had a double roller chain set. I wonder if it's running bad because of that retard computer?
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Old 11-17-2005, 06:42 PM   #10
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Re: Computer in my 85 (Questions)

You can probably fix the lockup problem also:
http://www.73-87.com/7387garage/drivetrain/lockup.htm

What year is your truck Chris?
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Old 11-18-2005, 12:53 AM   #11
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Re: Computer in my 85 (Questions)

It's an 86

After reading that I don't know if that's the problem or not, since it sems to only matter in 4th, it drive great after you get going just take off stinks horribly. It shifts real quick, normal, and if hard acceleration it shifts very slowly like hangs the gear for a good while.
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Last edited by benoit454; 11-18-2005 at 12:57 AM.
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Old 11-18-2005, 04:32 AM   #12
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Re: Computer in my 85 (Questions)

Chris, it sounds like you have a problem with the TV cable on your 700. Here is how to adjust it: http://www.73-87.com/7387garage/drivetrain/tvcable.htm
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Old 11-18-2005, 01:21 PM   #13
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Re: Computer in my 85 (Questions)

I'll have to try that you think that may be why it has no get up or go from take off?
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