IHADAV8.com - Turbo Buick Tech, and Nonsense

Tech Area => General Buick Tech => Topic started by: TurboCajun on March 09 2014, 04:45:01 PM

Title: no spark on 84 GN
Post by: TurboCajun on March 09 2014, 04:45:01 PM
its an 84 GN with 87 module and coil, I went thru the trouble shoot guide from Steve's site. after all the testing, it says to change the module. owner purchased a new one and was installed. no luck, today I went thru the whole check list again and its saying a bad module. here is what I found. I have crank signal from the crank sensor to the module but no signal coming out of the module to ecm. I looked around for something that would control the module not to send the signal but no luck. any ideas guys are did we just get a bad module out the box? :icon_confused:
Title: Re: no spark on 84 GN
Post by: Steve Wood on March 09 2014, 04:49:33 PM
do you have voltage on both the power feeds?
Title: Re: no spark on 84 GN
Post by: TurboCajun on March 09 2014, 04:51:49 PM
yes everything checks  out except for the signal that goes to the ECM
Title: Re: no spark on 84 GN
Post by: Steve Wood on March 09 2014, 05:03:47 PM
pull the coil/module off yours and see if that works...afterm arket modules are often flaky-particularly the Wells brand
Title: Re: no spark on 84 GN
Post by: Steve Wood on March 09 2014, 05:09:18 PM
also be sure it is bolted down to the bracket and the bracket to the back of the intake as this is the module ground
Title: Re: no spark on 84 GN
Post by: TurboCajun on March 09 2014, 05:10:42 PM
One thing I said I did not want to do is take parts from my car. but I may have to
Title: Re: no spark on 84 GN
Post by: TurboCajun on March 09 2014, 05:13:08 PM
part is a BWD from pep boys
Title: Re: no spark on 84 GN
Post by: Steve Wood on March 09 2014, 05:18:51 PM
swapping parts like the coil/module is about as simple as it gets and it saves a ton of time...
Title: Re: no spark on 84 GN
Post by: tb3 on March 12 2014, 02:54:06 PM
I remember years ago powdercoating my ignition module bracket on my hot air.
no worky until I grounded it with a bonding braid
Title: Re: no spark on 84 GN
Post by: Steve Wood on March 12 2014, 08:59:53 PM
I meant to ask him if it was bolted down...seen more than one that would not run because it was not grounded...gla d you brought it up
Title: Re: no spark on 84 GN
Post by: tb3 on March 13 2014, 01:32:09 PM
I meant to ask him if it was bolted down...seen more than one that would not run because it was not grounded...gla d you brought it up
I'm having trouble recollecting in my small brain, but I seem to remember a adapter bracket (usually sold by caspers) that allows the ic'd ignition module to bolt onto the hot air bracket, which means possibility of another grounding barrier, depending on how thick paint is, and if appropriate washers where used.
Title: Re: no spark on 84 GN
Post by: TurboCajun on March 22 2014, 06:28:48 PM
question- put 2 new modules on the car and both are doing the same, going thru the trouble shoot it tells me that the modules are bad, he it is . key one I have power to the blue wire on coil pack , also have power to the other three wires when connected to the coil but not when i pulled them off, the blue,green,yellow wires on the opposite side are suppose to blink when cranking not be on constant. I also disconnect the crank sensor and they stayed on.
Title: Re: no spark on 84 GN
Post by: Steve Wood on March 22 2014, 09:11:49 PM
does it have injector pulse when cranking?
Title: Re: no spark on 84 GN
Post by: TurboCajun on March 22 2014, 10:21:18 PM
this is what i am dealing with
Title: Re: no spark on 84 GN
Post by: TurboCajun on March 22 2014, 10:29:17 PM
I made a bracket to hold the module and also ran a ground wire for piece of mind,

Title: Re: no spark on 84 GN
Post by: TurboCajun on March 24 2014, 06:44:02 PM
ok==== I have no injector pulse,
Title: Re: no spark on 84 GN
Post by: Steve Wood on March 24 2014, 07:16:24 PM
that would take you to crank sensor given you have done the module....with a big assumption that the wires show continuity end to end
Title: Re: no spark on 84 GN
Post by: TurboCajun on March 24 2014, 08:00:07 PM
bad thing is on the 85 the crank sensor is hard wired into the sensor. when I was running the test, the sensor was showing good IDK
Title: Re: no spark on 84 GN
Post by: Steve Wood on March 24 2014, 08:13:19 PM
not sure what you mean by hard wired, but that is okay...I don't wanta know anything about a hot air car....:D

Does it have a double slot like the ic cars where it can be installed incorrectly?
Title: Re: no spark on 84 GN
Post by: TurboCajun on March 24 2014, 08:15:24 PM
I think so, I will check on it tomorrow.

Title: Re: no spark on 84 GN
Post by: Steve Wood on March 24 2014, 08:24:32 PM
looking at C4B on the 85 tree, seems like it could aim at the crank sensor as well...
Title: Re: no spark on 84 GN
Post by: tb3 on March 25 2014, 02:00:12 PM
earlier crank sensors had the plug molded into the bracket.  later ones had wires coming off it and then the plug
Title: Re: no spark on 84 GN
Post by: Steve Wood on March 25 2014, 05:32:17 PM
still looks like it needs a new crank sensor to me...
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