86 305 4BBL no spark, help!
#1
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86 305 4BBL no spark, help!
I recently bought a 1986 Camaro Sport Coupe with the 305 4bbl (LG4 I believe). When I got it, it ran like a champ! But then one day, after driving it to a thrift store, out of the random, it wouldn't fire up at all. I let it sit for a few hours there (cause it was like 103 outside lol) and replaced the icm. It started right up after that.
Drove it home, and the next day, nothing. It would then only start when it wanted to, not all the time. 3 weeks passed, and it would not do anything. I replaced the coil, distributor cap, rotor and icm (twice) around 2 weeks ago. As of today, i got a new ecm and still nothing.
I'm losing my mind on this, and I don't know why it won't get spark!
P.S. I do get fuel and there is good compression on all of the cylinders.
Drove it home, and the next day, nothing. It would then only start when it wanted to, not all the time. 3 weeks passed, and it would not do anything. I replaced the coil, distributor cap, rotor and icm (twice) around 2 weeks ago. As of today, i got a new ecm and still nothing.
I'm losing my mind on this, and I don't know why it won't get spark!
P.S. I do get fuel and there is good compression on all of the cylinders.
#3
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Re: 86 305 4BBL no spark, help!
thanks, I will look into that later today and let you know if that was the problem.
#4
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Re: 86 305 4BBL no spark, help!
See the section on testing the pu coil. The coil will produce a voltage as the engine is cranked.
http://www.chevythunder.com/hei_trou...ge_2_coil_.htm
how to check your pu coil voltage. Although this is for a small cap hei your results should be the same.
https://easyautodiagnostics.com/gm/4...ed-icm-tests-6
http://www.chevythunder.com/hei_trou...ge_2_coil_.htm
how to check your pu coil voltage. Although this is for a small cap hei your results should be the same.
https://easyautodiagnostics.com/gm/4...ed-icm-tests-6
Last edited by Tuned Performance; 09-06-2018 at 07:45 PM.
#5
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
Re: 86 305 4BBL no spark, help!
just purchase a new distributor. your old one's probably near wore out anyway and the cost is negligible. should come with a new ICM anyway.
#6
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Re: 86 305 4BBL no spark, help!
Naf, I did end up getting a whole new distributor and it did run after that! but then i ran into another issue that happened about 15 minutes after we were timing it via rotating the distributor. i turned the key, it tried to start, and then i got nothing. no engine cranking, no nothing.
I figured the battery may have been slowly dying from me trying to start it while timing it, so i let it charge overnight. i tried again today after work, and i got nothing. i've read on some forums here with people of similar issues and they were saying it could be the neutral safety switch, starter, starter solenoid, maybe a fuse, etc. any ideas on what it could possibly be? it was running super well before this happened, by the way. everything was working normally.
I figured the battery may have been slowly dying from me trying to start it while timing it, so i let it charge overnight. i tried again today after work, and i got nothing. i've read on some forums here with people of similar issues and they were saying it could be the neutral safety switch, starter, starter solenoid, maybe a fuse, etc. any ideas on what it could possibly be? it was running super well before this happened, by the way. everything was working normally.
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#8
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Re: 86 305 4BBL no spark, help!
i am getting power to everything else including the radio, all lights (interior and exterior), gauges, etc. when i turn the key, i get a buzzing noise behind the gauge cluster (i think its there, im not 100% sure) and the temp gauge flutters. the battery is at 12.7 volts when sitting and 12.3 volts when i turn the key, so the battery is good. so is the neutral safety switch and starter, as my friend and i tested yesterday. we are thinking it could be the starter relay, but we haven't been able to find a wiring diagram showing where it is to diagnose it. does anyone know where the starter relay is on an 86 camaro with a 305 4bbl v8?
#10
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Re: 86 305 4BBL no spark, help!
no, it won't crank. all i get is a faint noise behind the gauge cluster, i believe. it did get spark before the problem occurred, as i replaced the distributor and fixed my no spark problem.
Last edited by 88camaroswag; 10-11-2018 at 11:40 PM.
#11
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Car: 1987 SC/1985 TA
Engine: 350/vortec/fitech
Transmission: T56
Axle/Gears: 3.27 9-bolt
Re: 86 305 4BBL no spark, help!
look for 12V to the starter batt connection, the large gage wire to the starter should show same as batt voltage at all times.
If good, you can test the starter by applying 12v to the starter terminal on the solenoid. connect a jumper to the smaller gage wire connection on the solenoid and the starter should engage and spin the motor.
sounds like you may have a weak battery though.
If good, you can test the starter by applying 12v to the starter terminal on the solenoid. connect a jumper to the smaller gage wire connection on the solenoid and the starter should engage and spin the motor.
sounds like you may have a weak battery though.
#12
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Re: 86 305 4BBL no spark, help!
I will definitely try what you said later today hopefully. And also just to clarify, the battery I have is around 2 years old, maybe a little newer I'm not 100% sure. I don't think that is the problem, but I guess anything is possible, huh? Haha
Last edited by 88camaroswag; 10-10-2018 at 06:24 PM.
#13
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Re: 86 305 4BBL no spark, help!
so it ended up being the starter that just suddenly stopped working. i replaced it yesterday and it magically started up! lol
now all i need to do it time it properly and she's good to go!
now all i need to do it time it properly and she's good to go!
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