# nissan altima will not start, but cranks hard



## nissanaltimaa (Aug 8, 2017)

after disconnecting battery car will not start. big problem here is i replaced the crankshaft and camshaft position sensors. one of these, the one with the silver cylinder, was for a v6 engine. but the car is a v4. the car will not run now. not sure if i should buy the sensor for the v6 " the old one got damaged while being removed" and try that. it doesnt seem right putting the wrong part on my car also it is a real pain getting too it. any ideas peeps


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## smj999smj (Jan 1, 2006)

From what I see, the cam pos sensor is a different part number than the crank position sensor on either engine. The I4 and V6 share the same cam position sensors, but the crank position sensors are different. Step one for me would be to make sure you have the correct sensors in the correct place. If that doesn't fix it, you may have a bad sensor. When you replace these sensors, it's best to stick with genuine Nissan or Hitachi parts. Aftermarket sensors tend to be of lower quality and can be problematic.


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## nissanaltimaa (Aug 8, 2017)

they are indeed in the right place. and both sensors are new. its not working properly i think because for whatever reason it had im guessing the crank sensor for a v6. the guy at auto zone thought i was crazy. he said there was no way for the car too run with that sensor in it. but it had been since i bought it. the car itself has been a bit of a lemon really. ive put about 1600 into it this month alone. i appreciate your response. as my wife is having to drive me to work everyday.


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## rogoman (Dec 16, 2004)

nissanaltimaa said:


> after disconnecting battery car will not start. big problem here is i replaced the crankshaft and camshaft position sensors. one of these, the one with the silver cylinder, was for a v6 engine. but the car is a v4. the car will not run now. not sure if i should buy the sensor for the v6 " the old one got damaged while being removed" and try that. it doesnt seem right putting the wrong part on my car also it is a real pain getting too it. any ideas peeps


It would have been helpful if you had stated the year,engine type and transmission type of your car. We don't have Internet X-ray vision; we're just in front of a monitor.

Did you replace those sensors prior to disconnecting the battery; with today's car electronics, it's smart to first disconnect the negative (-) side of the battery prior to doing work on electrical components. What enticed you to replace the sensors to begin with; were you having operational problems with the car? Just as SMJ said, make sure to have the proper sensors installed. V6 sensors in an I4 either won't work at all or work incorrectly.

One of the first things to do is perform an ECU code readout with a portable scan tool to see if any fault codes are set. The tool can be purchased at most auto parts stores. Post the actual codes here on the forum so that we may be able to help you further. If there is one or more fault codes set, they can help point to the malfunction. If you have a copy of the FSM for your vehicle, the code readout procedure is described there along with a listing of codes. You can download a copy of the FSM from Nissan Altima Service Repair Manuals. The section EC.PDF is the one you need to read.

At this point you'll have to determine if there's an ignition or fuel delivery problem:

* Testing fuel delivery:
An easy way to test the fuel pump and filter is to disconnect the fuel hose from the fuel block; you should use a "quick connect adapter" and connect a long length of spare hose on to the "adapter" with the other end draped over the fender going into a catch can placed on the ground. Now turn the ignition key to the run position but DO NOT TRY TO START THE ENGINE. You should see fuel going into the can at a good rate for several seconds.

Tee-in a temporary fuel pressure gauge between the fuel block and "adapter". If the engine is unable to start, turn the ignition key to the run position but DO NOT TRY TO START THE ENGINE. The fuel pressure reading should be around 51 psi which would be a static reading.

The fuel injectors may not be firing. This can be tested with a "NOID" light probe for each injector harness connector.

* Testing ignition:
Pull several coil packs to test; use a spare spark plug in the coil pack to test; ground the plug base with a jumper wire to the engine block; see if you're getting a spark while trying to start the engine.


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## nissanaltimaa (Aug 8, 2017)

it is a nissan altima 2005 2.5. i disconnected the whole battery because it was in the way of me replacing the radiator and i was putting in a water pump. i replaced the sensors just for preventive maintenance, and i replaced the value cover and sparkplugs because i had a gasket leak. the radiator had a small leak. so i replaced everything for the cooling system except the heater core and a few coolant hoses. i also need to take this car in to get all the air pockets out. they seem extremely stubborn to do yourself. the only thing i noticed about both sensors is the v6 one is a bit longer. regardless i have learned my lesson to not buy a car from a sketchy impound lot. sorry i should have put details first. ill have the code readings up later today thanks. 

Note- the car did start up twice after the everything was done. i didn't drive it, i was trying to get the air pockets out. they were not clean starts though. im getting fuel and spark. i don't know about compression though.


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## smj999smj (Jan 1, 2006)

If you have a crank position sensor for a V6, then replace it for the correct part. Having an inductance-type sensor that is longer than the original part changes the air gap between it and the reluctance gear which triggers it.


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