'91 Vert won't start
Pro
Joined: Sep 2012
Posts: 732
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From: the confused state CT
Have you confirmed that there is no spark? Another possibility is no injector pulse. By checking these you can narrow down the effected circuit. Also, Do you know if it has/had an aftermarket alarm or remote start system? The mystery wire could be from that if the car has one of those.
Gary
Gary
Safety Car
Joined: Sep 2004
Posts: 3,953
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From: Mission Viejo CA
I might have thought not either but your '84 will have a note that it will (the way the FSM is done it's more visible as a warning) and all others it's a little more subtle and easily overlooked. Look at 8A-17 and it calls out (121) with an *. I'm quite sure I saw it noted after seeing "PA'S" post mentioning it for other years.
Odd that it mentions that and yet there's a blunt cut just hanging like you mention and "CCRAZOR" confirms. Does the blunt cut appear in the wiring schematic at the rear of the '84 FSM?
OP only needs to confirm condition of coil & module - move on.
Odd that it mentions that and yet there's a blunt cut just hanging like you mention and "CCRAZOR" confirms. Does the blunt cut appear in the wiring schematic at the rear of the '84 FSM?
OP only needs to confirm condition of coil & module - move on.
The extra white wire on the TACH terminal is not shown in the wiring diagram in the back of the big book. I'm guessing this was used during factory testing. I cut off this extra white wire in my car.
Thread Starter
Intermediate
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Team Owner
Joined: Sep 2003
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Went to this site http://chevythunder.com/hei_troubles...ge_2_coil_.htm and am following test instructions. Coil failed the first two tests. Hopefully that's the problem. You answered my next question. Car will run with tach wire not attached to distributor, right? Will install tomorrow. Just as an aside, could bad coil be reason tach stopped working?
Could coil effect tach operation? Yep but ....
Module is OK?
Last edited by WVZR-1; Jan 19, 2016 at 09:19 PM.
Thread Starter
Intermediate
Joined: Nov 2011
Posts: 43
Likes: 5
Have you confirmed that there is no spark? Another possibility is no injector pulse. By checking these you can narrow down the effected circuit. Also, Do you know if it has/had an aftermarket alarm or remote start system? The mystery wire could be from that if the car has one of those.
Gary
Gary
Racer
Joined: Mar 2015
Posts: 492
Likes: 40
From: SE Ohio
St. Jude Donor '16-'17-'18,'19
Went to this site http://chevythunder.com/hei_troubles...ge_2_coil_.htm and am following test instructions. Coil failed the first two tests. Hopefully that's the problem. You answered my next question. Car will run with tach wire not attached to distributor, right? Will install tomorrow. Just as an aside, could bad coil be reason tach stopped working?
Question 2 = if the tach quit before the car quit running, I wouldn't think so, but as WVZR you can,t rule anything out.
Open up the bundle of wires from the dist. to the back of the left head, the tach wire and tach filter and hopefully the other end of your white wire will be in there. I,d disconnect the battery first.
good luck
Pro
Joined: Sep 2012
Posts: 732
Likes: 72
From: the confused state CT
Can you suggest where I might look for evidence(other than this elusive loose wire) of an aftermarket alarm or remote start system
I asked the question based on your mystery wire. If the wire isn't factory one of these systems could be a possibility.
The remote starter systems may have a wire tapped into a circuit that indicates the car is running such as a tach,ignition module, or injector pulse signal.
I've found these aftermarket systems hacked into the cars wiring harness by the installer and end up causing problems.
Gary
