Mechanics

CAMSHAFT AND CRANKSHAFT SENSOR

2002 Nissan Sentra

Engine Performance problem
2002 Nissan Sentra 4 cyl Front Wheel Drive Automatic 113000 miles

How many ohms should the camshaft sensor read and how many ohms should the crankshaft sensor read?
Avatar
Kimandgayle
February 5, 2009.




http://www.2carpros.com/forum/automotive_pictures/55316_02sentracmps_1.jpg



http://www.2carpros.com/forum/automotive_pictures/55316_02sentrackps_1.jpg


Tiny
Zackman
Feb 6, 2009.
Thanks for the ohms and volts chart. I checked both sensors, checked out good. Fuel pressure is 59PSI. I cleaned the air intake sensor, but nothing has changed in the way it runs. Took it for a 10 mile run, when I accelerated (under a load) it would kick and buck as if I turned the key off, then back on. Probably 6 out of those 10 miles, the engine runs fine. It is as if an injector or coil is bad when it drops off, but it is like it is all of them simultaneously. At idle, it may run fine for 2 to 3 minutes, then just die. Starts right back up. I checked the wiring harness for maybe problems there, but nothing noticeable. There is no consistency to the problem, hot/cold, high/low rpm, acts the same. No codes are present, no check engine light. I have access to a snapon scan tool. Scratching my head. Would a fuel pump relay be intermittent to cause the engine just to drop off, shouldn't it slowly die if it were the relay? I am puzzled.

Tiny
Kimandgayle
Feb 7, 2009.
Try this diagnostic procedure.


http://www.2carpros.com/forum/automotive_pictures/55316_02sentrasurge_1.jpg


Tiny
Zackman
Feb 8, 2009.
I rechecked some items and checked others. Fuel pressure is 75 PSI dead headed and car running. Vacuum at manifold is 20. Checked fuel pressure regulator (working), checked for water in fuel, ran about 3 gallons out of return line while car was running. Camshaft and crankshaft sensor checked out exactly the same in ohms and volts. When it runs with out dieing, it is smooth. I am going to try and acquire the scan tool again and use it to watch each sensor voltage and action. Hopefully this will reveal something.

Tiny
Kimandgayle
Feb 9, 2009.
Did you happen to check the MAF sensor? I remembered a while back an 00 Sentra with 1.8L with somewhat similar symptoms, and the driver cleaned grease from her sensor, and the car worked great right after.

Tiny
Zackman
Feb 9, 2009.
Yes, cleaned an already clean MAF.

Tiny
Kimandgayle
Feb 9, 2009.
Then get your hand on the scan tool and check each sensor operates, let me know.

Tiny
Zackman
Feb 9, 2009.