so, i was digging under the hood of my 86 hatchback (with 2.0 TBI motor) and found some unused plugs on the harness, some were taped together yet unplugged and was wondering if anyone knew what they were for.
the first (brown wire) was unplugged, i did plug it in but it made my idle jump pretty high, so i left it unplugged
the second (white wire) was also plugged in, i tryed to unplug it, but saw no difference so i left it plugged in
the third (red wire) was just a female side of the plug, i found no male end anywhere, so couldn't test to see if it made any difference
~~1986 Chevy Cavalier CS~~
~~2.0 TBI~~
Brown one looks like the o2 sensor wire. The white one I have no idea, 3rd one is the fuel pump test port I believe to bypass the fuel pump relay for diagnostic purposes.
On the inside my car looks like a fighter jet.
Did a lil bit of research myself and found out the brown wire has something to do with setting the timing, not the O2 sensor
~~1986 Chevy Cavalier CS~~
~~2.0 TBI~~
White one should be for factory Tachometer. If you have the optional gauge cluster, you can disconnect this and see if it drops to zero. These cars are terribly difficult to swap gauge clusters on FYI.
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I've got no tach in my cluster though, so I guess I could just unplug the white one? And like I said, with the brown plugged in, it raises my idle a decent amount, but I left it unplugged because I'm trying to lower my idle. I do briefly remember seeing in my Haynes manual something about the brown wire having something to do with setting the timing but I can't rember what it said exactly lol
~~1986 Chevy Cavalier CS~~
~~2.0 TBI~~
I believe if my memory serves me correctly, the brown wire on my 87 Trans Am does control the timing.
To set the base timing,
you unplugged the brown wire so the computer would not try to control it, then you could move the distributor to set the timing mechanically, then you plugged the brown wire back in which allowed the computer to take over controlling the timing again. Not 100% sure if that's what your brown wire is for in this case, but it seems to coincide with a previous response. This would account for why your idle jumped high, because the computer changed your timing. I would continue to do some research on that wire and plug it back it in if it controls the timing. If the idle is too high, then I would track down the source of that problem and address that issue.
Well it would be better if he told us the car and not 86 hatch with 2.0tbi.
On the inside my car looks like a fighter jet.
But it's odd that it was unplugged for god knows how long (but it wasn't taped together, mabey it just came unplugged, the clip is busted on it) but that might be why I've got a lil hesitation when I step on the gas. I'll try and see if i can find my timing light this weekend and check the timing on it. The brown beast has been a big sluggish this past winter, sandy isn't the biggest fan of the cold weather hahaha. And this is random but my cars full name is "sandy turd", the reason behind that is the following
When I got her, the interior was full of sand, it took me a good 2 month to get ALL the sand out of this car, that's why I named her Sandy.
And my friends call it the turd because its a light brown color, and had a huge hole in the muffler when I got it, so it always sounded like it was farting when I'd get on the gas
And that is why we call her "Sandy Turd" hahaha, and that why I could never paint it. Cuz then it wouldn't be "the turd" anymore lol
~~1986 Chevy Cavalier CS~~
~~2.0 TBI~~
I coulda swore I added my car info to my signature, guess the settings didn't stick. But anyway my model is the following
1986 Chevy cavalier CS (base model) Hatchback, engine is the 2.0 TBI
Thought with all 1st gens the 2.0 motor would be identical?
~~1986 Chevy Cavalier CS~~
~~2.0 TBI~~
nope, in 86 was the first year for the turbo 2.0 in a sunbird. Most if not all Sunbird 4 cyl are different then cavaliers.
On the inside my car looks like a fighter jet.
Did not know that. But wasn't the cavalier the only 1st gen that came with a hatchback?
~~1986 Chevy Cavalier CS~~
~~2.0 TBI~~
You could get the 1st Gen Hatchback bodystyle in Chevrolet, Pontiac, Oldsmobile and even Buick in 1986. Only Make not offering the Hatchback was Cadillac. Be kinda neat for someone to scrounge up a Cimarron and a Hatchback and swap on the Caddy Front and Rear, Nameplates and maybe the interior. Wouldn't be much, but you definitely have a One-of-a-Kind !!
Used to love the hatchback bodystyle back in the day. Now I appreciate the usefullness of my wagon , guess I'm just getting old.
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The tan/white wire (or rather brown with the white line on it) at the blower is for when You set the timing initially.You unplug it to get the distributor adjustment to lets say 6* btdc.I have done this several times and just too tired to try and explain it.Anyway not hard to do and my chiltons has a pretty long description to do the cough step by step.This kind of bypasses the ecm adjustment until correct timing is adjusted.If I have any of this screwy so be it tired I am.
