Ruff Idle ,Huge Loss of Power

[Macroblock]

Originally Posted by Tripler

Pulled #8 and #5 at the same time and it idles ruff and sounds the same .

To double check, start and run the engine with 5 and 8 disconnected. Connect 5 and note any changes in idle. Connect 8 and note any changes in idle.

If connecting 5 and 8 didn't have any affect, it's pointing to an ignition problem. Perhaps a coil or the Ignition Module (DIS).

Sounds like you'll need to pull the plenum to test and repair further.

With the plenum off you can test the ECM (-) outputs to the injectors. A couple of noid ("solonoid") lights will come in handy for this. A basic 12v test light will be needed to simulate a Crank Hi signal to spoof the Ignition Module and ECM.

Let us know when you have the plenum off.

[32valvZ]

5 & 8 are the same coil... seems like that might be the problem

[Tripler]

Originally Posted by Macroblock

To double check, start and run the engine with 5 and 8 disconnected. Connect 5 and note any changes in idle. Connect 8 and note any changes in idle.

If connecting 5 and 8 didn't have any affect, it's pointing to an ignition problem. Perhaps a coil or the Ignition Module (DIS).

Sounds like you'll need to pull the plenum to test and repair further.

With the plenum off you can test the ECM (-) outputs to the injectors. A couple of noid ("solonoid") lights will come in handy for this. A basic 12v test light will be needed to simulate a Crank Hi signal to spoof the Ignition Module and ECM.

Let us know when you have the plenum off.

I fully expected to pull the plenum again . Will keep you updated .


;-)

[Macroblock]

Originally Posted by 32valvZ

5 & 8 are the same coil... seems like that might be the problem

Yup sounds like it - unless the Hi-Tension lead going to #8 is the issue. Perhaps the lead is creating high resistance or shorting to ground.

[XfireZ51]

You can take a look at my thread on chasing knock. If u go here, you can see what you may want to check for regarding ur coils.

http://www.zr1.net/forum/showpost.ph...8&postcount=16

[Tripler]

Originally Posted by XfireZ51

You can take a look at my thread on chasing knock. If u go here, you can see what you may want to check for regarding ur coils.



http://www.zr1.net/forum/showpost.ph...8&postcount=16

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 .

Thanks



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[Tripler]

I got the plenum off again . What are the steps to test the Coils .
Thanks


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[Macroblock]

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 .

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.

-----------------

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

[XfireZ51]

Here?s a good thread re: checking coil packs.

http://zr1.net/forum/showthread.php?...ignition+coils

[Tripler]

Shame the forum does not have a thumbs up option because I would really like to thumb up everyones posts . Extremely helpful . I have never heard of noids before lol but I see I can buy them here at our Canadian tire . On Monday I will check the ohm readings on the coils and attempt a test of injector electrical leads .

Thanks for that pic of the service module plug and coil ohm info


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