Replaced #2 injector and harness but still no fire?

Tiny
BIGBLUOBLK
  • MEMBER
  • 1994 NISSAN MAXIMA
  • 346,000 MILES
Gave the car a full tune up, plugs, wires, all filters and sensors even replaced the front harness to the injectors but still no fire on #2 cylinder? Compression test was good and I also replaced the rotor, cap and dist. What else can it be? Electrical? The owner before replace the original motor because of this problem and the same thing happened again the problem was not solved Lol! He gave the car to me so please help!
Monday, September 19th, 2011 AT 6:44 AM

17 Replies

Tiny
KHLOW2008
  • MECHANIC
  • 41,814 POSTS
Are you getting sparks?
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Monday, September 19th, 2011 AT 3:01 PM
Tiny
BIGBLUOBLK
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No spark only on the #2, unplug all other wires one by one and the engine runs very rough but the #2 wire is completely dead? The auto repair ran a diagnostic that said the #2 injector was bad so I replaced all 6 injectors plus the tuneup and still on spark on the #2 plug? Pulled everything off again and run the oms test on each injector and once again all tested great, I know for a fact all injectors are good.I even replaced the harness on the front 3 injectors and still no change?
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Tuesday, September 20th, 2011 AT 12:42 AM
Tiny
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The injectors have nothing to do with sparks. You need to find out if it is the the wires etc,

Did you test cylinder # 2 for sparks since it is not firing?

https://www.2carpros.com/articles/car-cranks-but-wont-start

The above link could be helpful.
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Tuesday, September 20th, 2011 AT 5:01 PM
Tiny
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Ok that make sense but plugs and wires are new plus the firing order is on point, is there anything else that can cause this issue? I even swapped the Dist with one off a used car but cap/rotor is new.#2 cylinder had a comp test at the dealer and the test reading was good. What did I miss? Coil, Computer, broken wire?
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Tuesday, September 20th, 2011 AT 9:48 PM
Tiny
KHLOW2008
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Are you getting any sparks at cylinder # 2?

Misfiring can be due to spark plugs, wires, rotor, distributor cap, injectors, compression, computer and wiring. You need to verify what is missing to be able to find out what could be causing it.
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Tuesday, September 20th, 2011 AT 10:02 PM
Tiny
BIGBLUOBLK
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So you're suggesting I replace the computer and maybe the harness connected to it? Plugs, cap, rotor, distributor, injectors, compression are all checking out good, it there a way to trouble shoot the computer after I remove it?
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Wednesday, September 21st, 2011 AT 1:10 AM
Tiny
KHLOW2008
  • MECHANIC
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You have not answered my question yet.

Do you have sparks at the cylinder when cranking the engine or when engine is running?

You need to understand if it is ignition sparks that is missing or the injector is not pulsing to cause the misfiring. Both are different. Ignition sparks is not related to the PCM if only one cylinder is midfiring but the injectors would.

You need to find the source/cause of the misfiring to proceed and DO NOT replace anything until it has been tested and confirmed to be bad.
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Wednesday, September 21st, 2011 AT 3:04 PM
Tiny
BIGBLUOBLK
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Just made another donation because of all my questions! Lol! Yes the car is running when I'm make the test, one by one I unplug the wires off the distributor and only the #2 wire has no spark jumping off the connector? I replaced the injectors because the dealer said the misfire was because the #2 injector was bad. So now we know that was false because the injectors are all new plus all plugs/wires/cap/rotor all new too but still I have a misfire on cylinder 2. I'm puzzled?
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Thursday, September 22nd, 2011 AT 8:32 AM
Tiny
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Thank you for the donation.

If there is no sparks from cylinder # 2, there are only a few things that can cause that.

1. Distributor cap.
2. Spark plug wires.
3. Distributor.

You mentioned swapping the distributor. Was it the same problem of cylinder # 2 not firing? Could it have been a different problem when the swap was made.

From what you had described and done, the distributor is the most likely suspect since it is sparks that you are not getting. Remove the distributor cap and rotor and check the reluctor gap for cylinder # 2.
Recheck the wire installation. Replca it with any otherknown good wire and retest for sparks. New wires can be faulty as well.
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Thursday, September 22nd, 2011 AT 3:44 PM
Tiny
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The #2 was the problem before I made any changes or swaps, The distributor is the only part that was not a new in the box when I got it.I'll give that a try this Saturday and give you an update soon, Thanks alot!
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Thursday, September 22nd, 2011 AT 10:29 PM
Tiny
RIVERMIKERAT
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Bigbluoblk, were you able to resolve this issue?
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Monday, November 28th, 2011 AT 1:39 AM
Tiny
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Replaced the computer and now good spark on the #2 but when the #2 wire is disconnected there is no change in the motor idle even though there is spark? I'm going to replace the complete harness from the ECU and also the crank sensor in the dist. Hope that works! Keep you informed.
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Monday, November 28th, 2011 AT 6:37 AM
Tiny
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Ok. Let us know.
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Monday, November 28th, 2011 AT 6:41 AM
Tiny
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Check if the injector is pulsing. Removbe the spark plugs and swap it with another cylinder. Prolonged misfiring could have damaged the spark plug for # 2 cylinder.
Have the compression tested.
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Monday, November 28th, 2011 AT 12:53 PM
Tiny
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Verify the spark plug gap.
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Monday, November 28th, 2011 AT 9:12 PM
Tiny
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Well I replaced the ECU harness and still a miss on the #2 even though there is good spark, so I guess the only other thing is to replace that #2 injector. Question? What sends the pulse to the injectors?
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Friday, December 2nd, 2011 AT 4:55 AM
Tiny
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The ECU.
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Friday, December 2nd, 2011 AT 5:18 AM

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