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Jay, Nissan Technician
Category: Nissan
Satisfied Customers: 20098
Experience:  20+yrs experience with Nissan & Infiniti Trained & Certified.Currently still working for Dealer
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06 Nissan Pathfinder 4.0 L. I have a intermittent spark it

Customer Question

06 Nissan Pathfinder 4.0 L.Hi. I have a intermittent spark it try to start but doesn't it has compression it has fuel, I got a new Crank sensor, no codes .
JA: Are you certain it's the fuel pressure sensor that's in need of attention? What about the fuel rail? Have you checked it yet?
Customer: yes because when I check the compression the spark plug it was wet, and I spray staring fluid and does the same
JA: Are you fixing your Pathfinder yourself? What have you tried so far?
Customer: yes
JA: Anything else you want the mechanic to know before I connect you?
Customer: I check everything swap relays check fuses check wiring plugs the only thing that I dont know is why it has intermitent spakr
Submitted: 10 months ago.
Category: Nissan
Expert:  Jay replied 10 months ago.

Hello my name is ***** ***** thank you for your question.

Did you get gas recently?

Customer: replied 10 months ago.
Expert:  Jay replied 10 months ago.

You mentioned you checked compression. What is the compression readings you are getting?

Customer: replied 10 months ago.
Customer: replied 10 months ago.
130- 126- 123- 125- 128-
Expert:  Jay replied 10 months ago.

Compression should be around 185 psi. 148 is the minimum. So if you have 120 psi of compression, you may have a internal engine issue and it doesn't have the proper amount of compression to ignite the fuel. That is why the spark plugs are getting wet.

Expert:  Jay replied 10 months ago.

Try disabling the fuel system by pulling the fuel pump fuse out of the IPDM and turn the engine over a few times, then recheck compression and see if it goes up. If not, then you have internal engine issues. Hopefully by disabling the fuel system it will dry the cylinders so it can see the actual compression . If there is unburned fuel in the cylinder it can wash out the cylinder walls and lower compression .

But you need to do this to determine if the engine is good or not first!

Customer: replied 10 months ago.
what that has to do with the intermittent spark?
it has new everything crank, pistons rings rebuild heads timing chain kit etc
I knock out the crank sensor when I install the engine and I replaced the sensor with a new one
Expert:  Jay replied 10 months ago.

If you have after market sensors, that can certainly cause intermittent spark and not throw codes.

Was this engine rebuilt?

Expert:  Jay replied 10 months ago.

Did you change this engine?

Customer: replied 10 months ago.
I took this engine out 3 times it is a long story but the the 2 times before this one it start right up,
Customer: replied 10 months ago.
rebuild are you reading what I write?
Expert:  Jay replied 10 months ago.

That is much more information that should have been outlined in your question.

You are providing new information, so I am trying to take all that in to help you. This 3rd time, is it the same engine? Was it rebuilt 3 times?

Customer: replied 10 months ago.
it had a aftermarket sensor before I got the new one
sorry is the same engine i took it out 3 times because it lost oil pressure when warm up and I did replaced the heads and pistons the 3rd time it was the o ring on the tensioners or the heads
all of this is irrelevant if the only answer to the intermittent spark is the aftermarket sensor I all ready replaced twice
Expert:  Jay replied 10 months ago.

Where did you get the sensor you installed? Also did you change the back timing cover gasket that blows out lowering the oil pressure?

Customer: replied 10 months ago.
I did replaced it on the 2 plates, one is like a y and the other is 4 inch long.
so you don't know why it has intermittent spark other than aftermarket sensor ?
Expert:  Jay replied 10 months ago.

If you have a After Market Sensor, it can produce intermittent spark. Also keep in mind, when checking for spark, it's not a heavy deep spark. It's actually fairly light and faint. But even if you were getting spark, the 120 to 130 compression is to low. The Minimum is 148

Expert:  Jay replied 10 months ago.

Or if the fly wheel was chipped when installing, that could do that as well since the crank sensor reads off the signal place of the flywheel.

Customer: replied 10 months ago.
the fly wheel can't be chip. the teeths are out and the signal plate is inside close to the block it has windows for the sensor to read.
so you are guessing? never had this problem before ?
Expert:  Jay replied 10 months ago.

I am not guessing at all. Keep in mind, I am not there to see everything you did. I have encountered after market sensors many times not producing spark properly. Plus I know the signal plate is the inside ring, and of course when you are installing a engine you can chip the signal plate if you bump trying to line up the engine. I have seen that!

Customer: replied 10 months ago.
remember it was running before 2 times and now it tries to fire up but it dose not because it has intermittent spark
Expert:  Jay replied 10 months ago.

You just told me you have low compression. That will keep it from firing also and cause the plugs to get soaked if it cant' burn the fuel.

What did you change the 3rd time you did the engine from the first 2?

Customer: replied 10 months ago.
I did knock out the crank sensor which I replaced twice.
I can see the spark from the coils whit a screwdriver to ground white and blue strong spark but only ones every 4 or 5 turns of the engine
Expert:  Jay replied 10 months ago.

That sound about right for the spark. It's not like a 4 cylinder where you see it almost every revolution.

You will see a spark when checking one cylinder every 3rd revolution or so. If you monitored spark on all 6 cylinders at once, you would see the spark is most likely there.

But what did you do to the engine on the 3rd time different than the first 2? You said it ran the first 2 times, but not the 3rd. So other than the low compression, I am trying to determine what else you may have done to cause the issue you are having now.

Customer: replied 10 months ago.
I'm sorry but i don't have time for this can you transfer me to some one else that can tell me what is the answer to my question
Expert:  Jay replied 10 months ago.

No problem. I will opt out and open this question back up to another expert and see if they can help you.

Keep in mind, I have been a Nissan tech for 26 years and the information I am asking for will most likely be asked by others.

I wish you luck and just wait for a reply from another expert

Thanks Jay!

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