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garycoleman
Novice
Mar 28, 2014, 10:16 AM
Post #1 of 13
(1576 views)
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z24 dead cylinders
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I have a 98 z24 2.4 twin cam the car sat for maybe 2 weeks and I go to drive it one day and its not getting fire from coil to 1 and 4 cylinders p0300 multiple misfire rebuilt motor @ +/- 80xxx I replaced pcm ckp cmp icm plugs coil housing getting 12v to coils I'm sure its electrical unfortunately I'm not to familiar with ignition or electrical systems I checked the timing everything seems to line up but the car is heavly modified shops wont touch it
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kev2
Veteran
Mar 28, 2014, 10:27 AM
Post #2 of 13
(1568 views)
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Re: z24 dead cylinders
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the answer STOCK is best is a little late,,, swap coils see if issue moves to other cylinders... the issue is likely in the coil mounting to the cover OR a loose wire at the 1-4 connector....
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garycoleman
Novice
Mar 28, 2014, 10:33 AM
Post #3 of 13
(1567 views)
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Re: z24 dead cylinders
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I tried that and a new coil housing
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kev2
Veteran
Mar 28, 2014, 10:53 AM
Post #4 of 13
(1561 views)
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Re: z24 dead cylinders
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then we need to confirm 12v at coil connector, and check the other wire for the switching signal - noid light- are often used to do this - it should flash when cranking... Do you need wire colors? - really it just 2 one will have the 12v the other is the switching, the switching should NOT be grounded- it will pulse to ground when the PCM fires 1-4
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garycoleman
Novice
Mar 28, 2014, 1:35 PM
Post #5 of 13
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Re: z24 dead cylinders
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I don't know what a noid light is or how to use it and exactly what wires and how to test each wire
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kev2
Veteran
Mar 28, 2014, 1:42 PM
Post #6 of 13
(1542 views)
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Re: z24 dead cylinders
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I do not know how to advise other than seek the services of a technician. This is basic technician skills- circuit testing and diagnosing
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garycoleman
Novice
Mar 28, 2014, 1:44 PM
Post #7 of 13
(1540 views)
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Re: z24 dead cylinders
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Could I just use a regular power tester and I believe its a orange and white wire that runs from pcm to icm correct?
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Hammer Time
Ultimate Carjunky
/ Moderator
Mar 28, 2014, 1:52 PM
Post #8 of 13
(1536 views)
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Re: z24 dead cylinders
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You're not checking power. You're checking pulsing ground on a very low impedance circuit. Just using an incandecent bulb can take out your computer or ICM. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.
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garycoleman
Novice
Mar 28, 2014, 4:39 PM
Post #9 of 13
(1525 views)
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Re: z24 dead cylinders
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So this noid light will just confirm I'm not geting signal.
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garycoleman
Novice
Mar 28, 2014, 5:32 PM
Post #10 of 13
(1520 views)
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Re: z24 dead cylinders
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Where can I get a noid light and where would I perform the test on the wiring
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Discretesignals
Ultimate Carjunky
/ Moderator
Mar 28, 2014, 5:34 PM
Post #11 of 13
(1520 views)
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Re: z24 dead cylinders
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Don't think you should use a NOID light on IC control circuits that goes between the ICM and the PCM. The PCM signals the ICM to fire the coils. There are two circuits one is 1-4 IC and the other is 2-3. It is going to be digital signals of either 5 or 12 V. Either the PCM will pull up or pull down those circuits. You can actually do a bypass test using a 12 volt test lamp on the IC circuits to see if the ICM fires the coils. That tests everything underneath the coil cartridge. If you can get the 1-4 coil to fire doing the bypass test, that leaves input, PCM, or wiring from the PCM to the ICM. The only way your going to test inputs, such as cam and crank sensor signals, is with a lab scope or graphing meter. Here is a video on bypass testing and ignition control testing (very good information if you can understand it): http://www.youtube.com/watch?v=jJmqdhhduVc http://www.youtube.com/watch?v=VG3EZJlyjl8 Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.
(This post was edited by Discretesignals on Mar 28, 2014, 5:42 PM)
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garycoleman
Novice
Mar 30, 2014, 7:37 AM
Post #12 of 13
(1486 views)
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Re: z24 dead cylinders
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That info was very informative for future reference but turns out coil negative white wire on harness pcm/icm ( for coil 1&4 cyl.) been spliced prior to me owning the car and came apart somehow, but the car is firing proper and running as it did before. Thanks again for the help Tec.
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Tom Greenleaf
Ultimate Carjunky
/ Moderator
Mar 30, 2014, 8:27 AM
Post #13 of 13
(1482 views)
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Re: z24 dead cylinders
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Good find. Trust you did a quality splice so that isn't a routine issue. I'll close this thread as solved to keep spammers out and you can ask any moderator to open it upon request, T
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