Nissan Repair Questions? Ask a Mechanic for Answers ASAP
What year is this car? Engine size?
Do you have the car with you now and will it start or not?
FIRST I DON'T THINK IT'S A TIMING CHAIN ISSUE EITHER. THAT WOULD BE PRETTY CONSISTENT IN MY OPINION.
WHEN YOU TURN THE KEY ON, DOES THE SERVICE ENGINE SOON LIGHT COME ON?
DO YOU HAVE A COMPRESSION TESTER OR A CODE READER TO SEE IF ANY CODES ARE BEING STORED?ALSO, DOES THE CAR HAVE A SECURITY LIGHT ON THE DASH?
if you unplug the crank sensor right now will the car start.
I need to know if the engine has ever been out of the car, or the transmission
also, the compression is a bit low, but it's not common for all cylinders to have precisely the same compression.
Does the car ever lose coolant and need to be topped off?
I understand they said that, I was just wondering if that was the case now or not.
I need you to check for spark, is that something you know how to do?
Pull an ignition coil and leave it plugged in. Then set it next to something metal and crank the engine. If there is spark it will jump from the coil to the metal on the engine. Don't hold it or it will zap you, just set it next to a bolt and you should see spark jump from the coil to the bolt while cranking.
I do not think the issue is the timing chain. Since it will start without the crank sensor plugged in, I think there is a problem with the signal wheel on the flywheel. I've seen this in the past on cars that have had the flywheel out or off and not installed correctly. Un plug the crank sensor and they start. Plug it back in and they don't. There is a problem with the ring on the fly wheel in my opinion. either it's loose or broken or it's been out and isn't installed properly.
I think the issue is there and the engine and transmission are going to have to be separated to find out what's going on in there.
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Sorry for the delay.
I would not pull it apart, but man it sure sounds like the issue is there. But, it might be the wiring from the sensor. If you look at the wiring harness clear up to the computer, you might see where it's chaffed and there is a wire making contact.
Also, if you didn't put a factory crank sensor in the car, that could be the issue as well. From the sound of it though, it's got to be the wiring or the sensor ring. With this explanation though, I would not rip the engine out just yet. You can also try a wiggle test on the harness. Wiggle the wires while cranking the engine. If it starts, then perhaps you are actually getting a wire to make contact.
That's fine, I should be online. I am really curious now! Seems like what you had done prior to this shouldn't be a factor if the wiring is good.
Check the wiring harness where it runs under the battery in the left front corner of the car. Starting to think there may be an issue to the ecm relay. This used to happen on the older models.
I find it odd that the computer will read at times and not at others. In the older models once in a while the power feed to the ecm relay would fail and the car wouldn't start. So, I am wondering if it's something like that, and when the car won't start it's because the computer will not power up
You are going to have to pull this engine and look at the flywheel. It's had to have been off the car or something for this to be going on. Otherwise I really have no answer as to what could be the problem. Maybe some sort of water intrusion, but honestly that seems unlikely. Since it will start and run with the crank sensor unplugged, it's got to either be an issue with the wiring for the crank sensor itself or something with the fly wheel in my opinion. You have eliminated everything else.
Just to be clear here, the engine cranks but doesn't start?
Well, you have to start with the basics, check and make sure there is spark. If there isn't any, then check for power at the connector at the coils, if there is spark, then spray some stating fluid directly into the throttle and see if the engine will fire off it for a few seconds. If it won't, then check for injector pulse with a noid light. If no pulse, then check the fuel injectors for power.
Also, if the battery is weak and the engine isn't cranking over fast enough, the computer won't come on and start the car.
If you have been cranking the car and it's not starting, the cylinders could be washed and that will give it low compression. This will prevent it from starting.
Try these tests in the order I have given you and let me know what you find when you are done.
and please, turn off your caps lock ;)
the computer is suppose to tell the coils for fire. It does this via the cam and crank sensor positions.
Can you please tell me the position of the crank sensor on the engine so I know you are looking at or unplugging the right sensor here?
It's the right one, if I had a dollar for the wrong sensor being replaced we would not be chatting here.
It seems like maybe their connection on the new pigtail could be to blame. If you have a scan tool that can see the engine rpms, hook it up and see if it sees the engine cranking and gives you any rpms. It should also show the timing degrees.
Let me know.
Not really, at this point we have to see what the computer is seeing and why it's not telling the coils to fire.
I would look under the dash for any signs of some kind of aftermarket security system on the car at this point. I am not sure what else can be done without proper testing equipment.