Sr20det cylinder 2 not firing

[ZenkiDK]

Hi everyone, so I go to start my car and notice the engine shaking violently and I can feel it throughout the car. I started diagnosing and pinpointed it to cylinder 2 not firing by unplugging the coilpack and seeing no change. Changed the coil pack and still no luck. The previous owner installed the engine by cutting/soldering the engine harness instead of getting the plug and play harness. I've had plans to buy a new harness and I think it may be time now, however, I would like to make sure it is a wiring issue, whether it be the coil pack sub harness or main harness. Any suggestions on how to go about this?

Thanks for your help.

Update 1/23:
All cylinders have 12v power. As for ecu signal:

C1 - .35
C2 - .12
C3 - .15
C4 - .25

[Juantwo3]

It just happened out of the blue?

[ZenkiDK]

Yep, car was running fine. Went to go start it and felt a lot of vibration. Checked out the engine and it was shaking like crazy.

[KAT-PWR]

Test signal from ecu to the pin for the coil pack

Ensure you're getting power to the plug and group it good.

[jr_ss]

Move cyl 2 coil to a different one and see if the symptom folllows. That will rule out coil

[bataangpinoy]

step one: buy a multimeter
step two: learn how to use it

Sounds like 5v ECU signal is not reaching C2.

[ZenkiDK]

step one: buy a multimeter
step two: learn how to use it

Sounds like 5v ECU signal is not reaching C2.

Just checked.
All cylinders have 12v power. As for ecu signal:

C1 - .35
C2 - .12
C3 - .15
C4 - .25

Leads me to believe its the harness. Anyone concur?

[koukimonst3r]

Just checked.
All cylinders have 12v power. As for ecu signal:

C1 - .35
C2 - .12
C3 - .15
C4 - .25

Leads me to believe its the harness. Anyone concur?


I concur, should have the same reading throughout if wiring is good.

[KAT-PWR]

Check for the signal where the main harness plugs into the coilpack sub harness. That will tell you if it is main harness or coil pack harness.

[bataangpinoy]

I would go through all the signal wires, C2 & C3 look suspect. Since you already tested the coil pack plug on the sub harness, test in 5 more places.

ECU plug

Input of the ignitor

Output side of the ignitor

Engine harness of the coil pack plug

Sub harness side of the coil pack plug




Record any voltage as you work your way towards the coils.

[brndck]

have you already ensured that the cylinder has good compression and that the injector is firing, and that the plug is in good condition as well?

[LoSt180]

Could also be a bad ignitor. I've pulled some apart before and the little transistors inside can get fried.

[cbeuglas]

I have had to replace my factory coil pack harness. It can definitely be an issue.

Sent from my SAMSUNG-SM-G920A using Tapatalk

[ZenkiDK]

Thanks guys for all the suggestions, I will look into the injector first to make sure that it is working and then go from there. Will keep you updated.
Thanks.

[LoSt180]

Thanks guys for all the suggestions, I will look into the injector first to make sure that it is working and then go from there. Will keep you updated.
Thanks.
Focus on verifying you have spark before moving to fuel.

[ZenkiDK]

Alright guys, just ran some tests and I'm more confused.

Firstly, I tested for spark and its there. However, while plugged into the engine, I removed coil pack 2 harness and it still made no difference, whereas unplugging the others makes the engine stumble and run rough.

Secondly, I tested the injectors by using the screw driver trick and all of them are clicking.



Any ideas what I should do next?

[LoSt180]

Did you try moving the coil pack to another cylinder and trying the test again? That will point to either a bad coil (if problem moves) or possibly wiring or something else.

[wurley]

next you should test compression. if it has compression then you'll have to pull the fuel rail and injector and make sure that injector is working.

[ZenkiDK]

Figured it out, took out the fuel rail and injector #2 is not firing. Now I can upgrade to the 550s that have been sitting around.

Thanks for everyones help!