Quote:
Originally Posted by Tripler
Wow, thanks for that . Very interesting .
Since the coils are 25+ years old I will switch those out first with new wires and plugs . If it still idles ruff and has no power then back to checking more bits .
I will need a bit of instruction on how to test the injector cables to make sure they are putting the right amount of voltage to the injector .
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Yes, good idea to change the ignition coils and perhaps the hi-tension leads while you have the plenum off.
The coils are all the same so if you want to test for the sake of testing you could exchange the coil that serves 5 and 8 with another coil and see if this moves the symptom to another cylinder pair.
If the problem moves, it's likely the coil but if it remains on 5 and 8, the problem could be a bad hi-tension lead or leads, bad plug or plugs or an issue with the Ignition Module.
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To test the ECM and injectors with the plenum off you will require a test light and at least one 'noid' light.
Put the key to "ON". Connect the test light alligator clip to the battery (+) and quickly and repeatedly connect and disconnect the probe end to the Crankshaft HIGH pin on the Ignition Module Test Port.
Pulsing a signal to the Crankshaft High line will spoof the ECM into thinking you are making a start attempt (i.e. <400 RPM). You will notice the fuel pumps come to life and a few other devices. All primary injectors will fire at the same time.
Now disconnect all the primary injectors. Put a 'noid' light on each injector connector or do one connector at a time if you only have one 'noid'. Spoof the ECM again and verify that each primary circuit lights up the noid.
Note 1 - The ECM output to each injector is (-).
Note 2 - If you don't have a 'noid' light a test light can be substituted.
Note 3 - Link to image of Ignition Module Test Port:
http://www.zr1ecm.com/img/blog/detai..._TEST_PORT.jpg
