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Mike V.
Mike V., Nissan Technician
Category: Nissan
Satisfied Customers: 25335
Experience:  Nissan factory trained and Certified Subaru Technician.
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I have a 2005 Nissan Altima 2.5L that will not crank most

Customer Question

I have a 2005 Nissan Altima 2.5L that will not crank most times on the first try and after several most of the time as well as being very sluggish coming off a dead or slow stop when running. When it is running it is smooth and doesnt cut out at cruising speeds. Just cant depend on it to crank right up most times. It doesnt matter if the engine is cold or hot. CMP, CKP, Timing chain w/guides, intake variable timing gear has been replaced and timing set right. Has code P0340 stored but not active in the ecm. CMP has a good ground, battery voltage and the ecm signal wire to ecm harness. When it doesnt want to crank it will spark once on the coil pack as well as pulse the injectors once when it is in a no start condition. Any ideas on this problem? Thanks
Submitted: 11 months ago.
Category: Nissan
Expert:  Mike V. replied 11 months ago.

Hello and thank you for your question!
My name is ***** ***** I will be assisting you with your question today.

Expert:  Mike V. replied 11 months ago.

Is it not starting now?
Has the engine been out of the car?

Customer: replied 11 months ago.
It will start at some point after several attempts or start right up on the first try. It will run when it decides to crank. Engine has been out but all the grounds are made and suffecient.
Expert:  Mike V. replied 11 months ago.

Ok so, for example, if I have you unplug the crank sensor and the car fires right up, we have no way of knowing if the issue is there and resolved or not right?

Customer: replied 11 months ago.
Right, I have had it unplugged and at times it has cranked and others when it hasnt. Just no way of knowing.
Expert:  Mike V. replied 11 months ago.

Ok

did you use a factory cam sensor from the dealer?
Also, can you have a scan tool on it to watch for cam and crank signal when you are cranking the engine?

Customer: replied 11 months ago.
Feel like getting a sledge hammer and going mid-evil on it! Yes, OEM sensors and I do not have a scan tool to see if the CMP and CKP are in phase with one another.
Expert:  Mike V. replied 11 months ago.

I am not looking to see if they are in phase, but which one stops sending signal. That's why you only get one spark. One of them is being bad and not sending the signal to the computer. This prevents the first and injector pulse.

I am a little bit suspicious of the cam sensor since the code won't clear out and stay out. Maybe not the sensor itself, but the wiring from the sensor back to the ecm could have a problem.

If you have a meter, check the wiring back to the ecm for continuity. That would actually explain the sluggish running too if the timing was off according to the computer. Do you have a code reader that can see the engine timing?

Customer: replied 11 months ago.
It shows 16 degrees idling. I checked the signal wire all the way to the ecm and I have continuity on the CMP but I did not check the CKP signal wire to the ecm.
Expert:  Mike V. replied 11 months ago.

Ok, 16 isn't bad at all, I would check the crank signal wire, and honestly if it looks good, I am thinking you might just have either a loose connection to one of these sensors or an issue with the ecm itself.

Customer: replied 11 months ago.
What was the problem with the ecms where Nissan had to reprogram them? That was going to be my second to last step but really didnt know what the main reason was that led to them being reprogrammed. I may run it to a shop to look at the cmp and ckp signals on a scan tool to make sure those issues you descibed are eliminated. Im just tired of working on this thing.
Expert:  Mike V. replied 11 months ago.

They aren't clear on the reason for the recall other then the engine could stop. You could call them with your VIN and see if the recall has been done. If not, then they will do it for you at no charge.

This could be the problem of course, 10yrs old you figure most are done, but you really never know. Any dealer can search your VIN and find out.

Expert:  Mike V. replied 11 months ago.

I hadn't heard back from you so I thought I would check and see if you needed further assistance with this?