Need help following Diagnostic chart.
09-15-2017, 06:17 PM
#1
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Car: 89 GTA, 84 T/A
Engine: L98 stock, Carbed 350
Transmission: 700r4
Axle/Gears: 3.27
Need help following Diagnostic chart.
Car died on my way home, no spark at ign coil.
Replaced coil, cap and roter. Car started ran alittle rough, but alright.
Went to start it today, won't start, no spark at ign coil. Started following the diagnostic chart:
Got to step 3, and I have no voltage on terminal C.
It says bad coil or connection.
Disconnected the harness and tested the wire with a circuit tester, twisted and bent it all over and it seems to be fine.
Pulled the ign coil, tested it in another car and it works fine.
So I'm not sure what to check next, unless it is the ICM that is bad, and that is not listed on the chart.
Replaced coil, cap and roter. Car started ran alittle rough, but alright.
Went to start it today, won't start, no spark at ign coil. Started following the diagnostic chart:
Got to step 3, and I have no voltage on terminal C.
It says bad coil or connection.
Disconnected the harness and tested the wire with a circuit tester, twisted and bent it all over and it seems to be fine.
Pulled the ign coil, tested it in another car and it works fine.
So I'm not sure what to check next, unless it is the ICM that is bad, and that is not listed on the chart.
09-15-2017, 06:21 PM
#2
Re: Need help following Diagnostic chart.
Here's another flow chart, to test the pu
http://easyautodiagnostics.com/gm/4....ed-icm-tests-1
http://easyautodiagnostics.com/gm/4....ed-icm-tests-1
09-16-2017, 02:20 PM
#3
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Car: 89 GTA, 84 T/A
Engine: L98 stock, Carbed 350
Transmission: 700r4
Axle/Gears: 3.27
Re: Need help following Diagnostic chart.
So I pulled the cap off, and tested the pickup coil, and it went to .5 volts and stayed there. According to the diagnostic it should vary between .3 and 1.8. I checked with both a digital multimeter, and an old analog meter.
Since I already had a spare ICM I went ahead and put that on and the car started right up.
So is the pickup coil still bad, or are my meters just not able to read the voltage fluctuations?
If I understand it right the pickup coil has to pulse in order for spark to be created.
Since I already had a spare ICM I went ahead and put that on and the car started right up.
So is the pickup coil still bad, or are my meters just not able to read the voltage fluctuations?
If I understand it right the pickup coil has to pulse in order for spark to be created.
09-16-2017, 08:15 PM
#4
Re: Need help following Diagnostic chart.
The analog meter should have saw fluctuations when testing the pu coil.
Its allways a good idea when replacing the icm to install a new pu coil .
I have seen the pu fail more than once after a new icm is installed.
Its allways a good idea when replacing the icm to install a new pu coil .
I have seen the pu fail more than once after a new icm is installed.
09-16-2017, 10:17 PM
#5
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Car: 84 TA orig. 305 LG4 "H" E4ME
Engine: 334 SBC - stroked 305 M4ME Q-Jet
Transmission: upgraded 700R4 3200 stall
Axle/Gears: 10bolt 4.10 Posi w Lakewood TA Bars
Re: Need help following Diagnostic chart.
I hope you used the proper white heat transfer paste under the module.
Dielectric grease is not the correct stuff.
Dielectric grease is not the correct stuff.
09-16-2017, 10:18 PM
#6
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Car: 89 GTA, 84 T/A
Engine: L98 stock, Carbed 350
Transmission: 700r4
Axle/Gears: 3.27
Re: Need help following Diagnostic chart.
Since I have to remove the distributor to replace the pickup coil, is there any other parts that should be replaced while it is out.
Or would it be better to get a whole new distributor.
edit - I used a tube of arctic silver thermal paste.
Or would it be better to get a whole new distributor.
edit - I used a tube of arctic silver thermal paste.
09-17-2017, 01:15 AM
#7
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Car: 84 TA orig. 305 LG4 "H" E4ME
Engine: 334 SBC - stroked 305 M4ME Q-Jet
Transmission: upgraded 700R4 3200 stall
Axle/Gears: 10bolt 4.10 Posi w Lakewood TA Bars
Re: Need help following Diagnostic chart.
Since you have already replaced so many parts, just replace the pickup and you are done.
