famous car not firing/sensors/electrical issues
 

Question type: Maintenance & Repair

3.5L V6 standard 6 speed transmission 110Kmiles
initial fault:
Replaced oil and drove car with no issues for 4 days. Then car started
hesitating and jerking, It ran extremely rough. SES light was illuminated
I changed spark plugs and got SES read by AutoZone.
Had fault codes for both camshaft position sensors, variable valve timing
solenoid.
I replaced all spark plugs properly, Car started but engine was not running
optimally. The hesitation and jerking still persisted.
I then replaced the camshaft sensors. Then the fun began. Car would not
start and fire. I started with the electrical side since i have a little more than general knowledge regarding circuits and electrical systems. After T/Sing. I found the battery to be bad. (battery was only 13 mos. old so warranty allowed swift exchange) I installed new battery and no luck. Pulled the starter and had it bench tested after doing voltage readings in the startup sequence. Bench test of starter turned out good and it passed. I did notice a bit of voltage drop across power wire. I will replace this part and it is on order currently.
Car still would not start so i did some research and found similar stories and people changing the crankshaft sensor. Rather than shotgunning another part out I removed and inspected it. And since i never received a fault code for it being bad i decided to clean it up using alcohol. After cleaning and allowing to dry for a day i reinstalled the crankshaft sensor. it was a rough start but the car fired up. I repeated this several times to ensure it was good to go or at least getting better. The car was hard to start up but it would turn over. It didn't hesitate, but there were some moments where i felt like it could start again. However the newest fault now was the RPM gauge wasn't working at all. I decided to go ahead and replace the crankshaft sensor. I installed the crankshaft sensor and car will not fire. As you can imagine i'm going in a ridiculous circle now and losing all patience. I swapped the new crankshaft sensor for the old and the car started up roughly again. I put the new sensor in and nothing. I decided to unplug the sensor and see if it would start. And you guessed it...IT DID. I plugged the connector back on and the RPM gauge was working perfectly. Car did not hesitate at all and is running strong. The problem is when i shut it off and try to restart it will not restart unless i unplug the crankshaft sensor. I also noticed that once i reattempt to start the car after driving it for a little bit it seems weak as if the battery is drained again.

I wanted to fill you in on everything I've done so far. I do not want to keep
this car much longer but do want to know what i can do to get it running and starting good so we can part ways.

My question is should i look into the ECM?? Timing issues?? I've taken the ground wire off the battery terminal and let it sit long enough to reset. I've also found a few links to procedures that can be done with pumping the gas pedal, holding it to the floor for 10 secs. etc. and that procedure doesn't seem to do anything to this car.
Any and all help/advice will be greatly appreciated.

You already found the problem, then. CKPS is shot and your replacement sensor is crappy. Sounds like nothing was ever wrong except the CPSs.

Unplugging the battery does not reset the ECU. You have to do the pedal dance. Your timing is just terrible, so it's not working (if the CEL doesn't flash, then it's not working).

thank you for the advice. I'll exchange the CPS for another and work on the timing until i can get the ECM to reset.

Did you try and clean the Mass Air Flow Sensor?

I was wondern if u ever got that thing straightend out or not.. it shure sounds like the crank sensor to me,but im kinda lost on how u say it ran with it unhooked.. the vehical cant possibly run without the cranksensor to tell everything when the # piston is tdc. and little advice on electrical parts. dont buy autozone or advanced thier electrical stuff is junk!! heres a link to a factory service manual hope it helps ya... www.boredmder.com

[QUOTE=chevyman1980;9089476]I was wondern if u ever got that thing straightend out or not.. it shure sounds like the crank sensor to me,but im kinda lost on how u say it ran with it unhooked.. the vehical cant possibly run without the cranksensor to tell everything when the # piston is tdc. and little advice on electrical parts. dont buy autozone or advanced thier electrical stuff is junk!! heres a link to a factory service manual hope it helps ya...
http://boredmder.com/FSMs/Nissan/Maxima/2000/

[QUOTE=chevyman1980;9089477]Incorrect. 3.5s do not need the crank sensor at all. It's only there to give a faster reading, so the engine can start instantly. Without it, the ecu just relies on the cam sensors and it takes up to several cranks before it fires.

Crank sensor can confuse the ECU big time. It's not needed, yet when it's messed up it can keep the engine from running or cause misfires.

wow gotta love nissan, that would defininatly throw me for a loop if i lost spark. crank sensors whear i usualy start. this new stuff is gettin bout rediculous. i was content with a 350 and a quadrajet.