I just replace the engine on my 97 hyundai elantra but won't start and i get a code p0335b

Here's a link to what your crankshaft sensor looks like. Duralast Crankshaft Position Sensor SU4127 ReadReviews onDuralast SU4127 The Crankshaft Position Sensoris located: Under hood, center, upper engine area, mounted in front passenger side of engine block.Here's another link on replacing your sensor.
Repair Guides Electronic Engine Controls Crankshaft Position ckp Sensor...

Hyundai 2011 "PRESS BRAKE PEDAL TO START ENGINE ...

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www.youtube.com/watch?v=4f4nS6BpNJY
Jul 16, 2012 - Uploaded by rdsinsandiego 2011 Hyundai Sonatas have been reported on the net by a few to have a random problem ... i have 2013 Hyundai sonata and the engine won't start when i use the key and turn on .... Had similar problem with my 2012 Elantra.

2013 Hyundai Elantra won't start - YouTube

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www.youtube.com/watch?v=uVNMgSE0nNA
Aug 29, 2013 - Uploaded by hellogoodbye1185
It will be fine for a couple of weeks then one day just won't start. ... my 2013 hyundai elantra also would not start but all the lights and radio were working .... Hyundai 2011 "PRESS BRAKE PEDAL TO START ENGINE" problem ...

2012 Hyundai Elantra Starting Issue - YouTube

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www.youtube.com/watch?v=pDzSgucZ1tw
Oct 10, 2012 - Uploaded by carupz421
So if your Elantra won't start, turn the key to where you can move the shift .... Having exact same problem on my 2011 elantradid you find out ...

Have you figured out if you are lacking spark to the plugs or fuel pressure when it fails to start ?

hyundai paint code location, Inside driver's door jamb or the door edge. for 97 to 2008 models, for the elantra. have a good day !

compression test, coil issue,

check the vacumn pipes that run to to advance unit near the ignition module

check timming belt it has jumped a notch

If the replacement thermostat is good, and installed properly, then the temp sensor might be bad. I hate to tell you ($$$$$) but waterpump could be bad (more expensive)

hi no engine codes showing as this is normally the ecu,s engine temperature switch if no codes get the ignition coil checked out while it won,t start yates210456

try pushing the clutch to the floor with you toes if it starts and won't unless you push to the floor its the clutch start switch 22 bucks at auto zone i will be gettng help installing the new one i will let you know.