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-   -   which cylinder is number 1? (https://x.nissanhelp.com/forums/sentra/21070-cylinder-number-1-a.html)

bhawk 01-01-2012 05:11 AM

which cylinder is number 1?
 
2003 sentra with 1.8 engine. I'm getting a P0301 code, which is misfire on number 1 cylinder. My question is--- which cylinder is number 1? I presume it is near the front of the engine where the crankshaft pulley and belts are, (which is the passenger side of the car). I presume number 4 is at the drivers side. Am I right?

mpe235 01-01-2012 05:16 AM

Correct. It is usually a coil. Could also be a head gasket leak. Try swapping #1 and #2 coils to see if the misfire changes to cyl. #2. If it does it's a bad coil.

bhawk 01-01-2012 06:07 AM

thanks for the quick reply. What I did not mention is that the misfire only occurs on a relatively cold start, where the engine misfires for only a few seconds, say 3-6 seconds, then runs fine. Occasionally in the past couple of years, or perhaps frequently, but not always, I found the engine had to be cranked over for quite a few seconds to get it to start. That symptom seems to indicate a weak fuel pump. But it has only been the last few days where I got the code and it stumbles on a cold start. So head gasket is possible too, based on my reading here. When I get time, I will remove spark plugs and check compression. I was thinking I should do a fuel pressure test.
How do I do a fuel pressure test? I have a gauge I once used on my son's ford ranger.
thanks to all for help.

mpe235 01-01-2012 06:41 AM

Quote:

Originally Posted by bhawk (Post 74645)
thanks for the quick reply. What I did not mention is that the misfire only occurs on a relatively cold start, where the engine misfires for only a few seconds, say 3-6 seconds, then runs fine. Occasionally in the past couple of years, or perhaps frequently, but not always, I found the engine had to be cranked over for quite a few seconds to get it to start. That symptom seems to indicate a weak fuel pump. But it has only been the last few days where I got the code and it stumbles on a cold start. So head gasket is possible too, based on my reading here. When I get time, I will remove spark plugs and check compression. I was thinking I should do a fuel pressure test.
How do I do a fuel pressure test? I have a gauge I once used on my son's ford ranger.
thanks to all for help.

The long crank could be caused by a faulty fuel pressure regulator. After the car sits overnight turn the ignition to the on position for about 20 seconds and then try starting it. It should start normally. Unfortunately the regulator is part of the pump assembly. Nissan came out with a repair kit but it is only a few dollars cheaper than the whole assembly.
Before you do the compression test remove the spark plugs and shine a light into the holes. If the top of the piston in any of the cylinders looks clean then the head gasket is leaking coolant into that cylinder.

nissanmaniac 05-28-2012 08:37 AM

the one closest to the crankshaft pulley

bhawk 05-28-2012 10:09 AM

My problem turned out to be antifreeze leaking into number 1 cylinder from a bad head gasket. I changed it out myself. Not really that hard a job. I was impressed with Nissan engineering as the engine is made to take apart easily. thanks for all your help guys.

NissanTech 05-28-2012 11:04 AM

Quote:

Originally Posted by bhawk (Post 79002)
My problem turned out to be antifreeze leaking into number 1 cylinder from a bad head gasket. I changed it out myself. Not really that hard a job. I was impressed with Nissan engineering as the engine is made to take apart easily. thanks for all your help guys.

Thanks for letting us know and I'm glad you fix the problem. :driving

[email protected] 01-25-2016 09:12 PM

Quote:

Originally Posted by bhawk (Post 79002)
My problem turned out to be antifreeze leaking into number 1 cylinder from a bad head gasket. I changed it out myself. Not really that hard a job. I was impressed with Nissan engineering as the engine is made to take apart easily. thanks for all your help guys.

I also have miss number 1 cylinder. too many people have same problem.
if antifreeze leaking into cylinder, than level of antifreeze must drop.
if level of cooling are same - few days than it can not be leaking antifreeze
am i right?

smj999smj 01-26-2016 07:53 AM

Quote:

Originally Posted by [email protected] (Post 98373)
I also have miss number 1 cylinder. too many people have same problem.
if antifreeze leaking into cylinder, than level of antifreeze must drop.
if level of cooling are same - few days than it can not be leaking antifreeze
am i right?

Not necessarily. It would take a pretty significant head gasket failure to make a noticeable drop in the coolant level, especially on just one cylinder. I would swap the ignition coil with another cylinder, erase the code, and see if the misfire follows the coil. If it does, you have a bad coil pack.

[email protected] 01-26-2016 04:28 PM

hi
i have question:
how car computer knows that cyl 1 mis fire?
is in combustion chamber placed some censor ?
what signal to computer that any cylinder mis fired?
how to check that power comes to coil at all ? there is 3 wires and they are low voltage 12 V etc
maybe problem happen before coils?
what unit sends power to the coils? maybe problem there
thanks

smj999smj 01-26-2016 05:49 PM

The ECM uses the crankshaft position sensor to determine engine speed as well as to detect engine crankshaft acceleration at each injection pulse, which is compared to the input from the cam position sensor to determine if and what cylinder is misfiring.
The ECM controls the power transistor, which is at the top of each coil pack, which controls the firing of the coil mounted directly below it.
The problem definitely could be the ECM or circuit between it and the coils. That's why I recommend swapping the coils, erasing the trouble codes, and seeing if the misfire follows the coil. If you swap #1 and #2 coil packs and the ECM triggers a #2 misfire code, then you know the ECM and circuit to #1 is good and the trouble lies in the coil pack that was formerly at #1 position but is now at #2 position. This would tell you that the problem is in the coil pack itself. If the misfire is triggered at #1 after the swap and didn't travel to #2, then you know you don't have a bad coil pack and will have to look elsewhere for the problem.
Checking power at the circuits, shorts and opens in the wiring circuits, etc., are all covered in the factory service manual trouble diagnostic steps. I would highly recommend, if you are interested in this, obtaining a Nissan Factory Service Manual for your vehicle. You may be able to find an "EC" (engine control) chapter of the service manual for your vehicle in the "knowledge base" available for free download in Adobe .pdf format. You can read an explanation of the how the ignition system works as well as find trouble diagnostic steps for P0301. The diagnostic procedures are very thorough and provide pictures of harness connectors and wiring schematics relevant to what's being tested. It will step you through the process until the exact cause can be isolate. I recommend doing the coil swap test, first, because it's an easy way to eliminate a lot of diagnostic steps if in fact your coil is the failed part.

[email protected] 01-26-2016 07:26 PM

about ---You may be able to find an "EC" (engine control) chapter of the service manual for your vehicle in the "knowledge base" available for free download in Adobe .pdf format.
can you please send to me internet link to service manual for vehicle in the "knowledge base"

smj999smj 01-26-2016 11:06 PM

This link will take you to the factory service manual chapters available for download for your vehicle in the "knowledge base" section. The "Engine Control" chapter is what you'll want:

http://x.nissanhelp.com/forums/Knowledgebase/links/114/


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