New motor - Will crank, but not start

[ProjectMPS]

I bought a 2007 Mazda Speed 3 in the winter with a shot motor. The past 2 months have been very busy swapping in a new motor. The motor is from 2012 Mazda Speed 3 (used motor with about 90,000KM). From my knowledge there are not too many differences between the 2 motors.I replaced anything that was worn or broken: new clutch, new spark plugs, fresh fluids etc. I am using the transmission only the long block is newer it is a used motor. The motor turns over but doesn't spark. I have fuel. I have to check for spark.

I moved any parts I needed that the motor didn't come with from the old longblock to the new one.

The engine is cranking but won't start. It is throwing a P0335 - crankshaft positioning sensor circuit fault. I don't know what else to test.

If you need any other information please leave a message!

[kTaLgsTo]

Assuming the engine is in tip top shape, check all of your grounds, missing ground straps/wires can really eff you up.

[Fstrnyou]

I would think a CPS fault will trigger a no-start safety measure in the ECU. How would it know when to fire the coils if the ECU doesn't know where the crank is?

[5doorsoffury]

Well the first thing i would do is get a meter out and test for continuity end to end on that CPS harness and the ecu harness. Next is if it says cps fault i would swap in a known good sensor for testing. Then i would check the infamous coil ground wire that is on the bracket in front of the HPFP. It grounds the coils.

[danb]

Which wire harness did you use?

[darkmx-6]

Make sure you used all the electronics from your car not the 2012. As there may be some unseen differences.

[danb]

Originally Posted by darkmx-6 Make sure you used all the electronics from your car not the 2012. As there may be some unseen differences.

Yes, you must use the gen 1 harness on the gen 2 motor. I just did this swap a month ago

[Polish_Eagle]

Are the camshaft trigger wheels the same on a 2012 and 2007? If not, you'll need to partially disassemble the engine and swap the camshafts.

[Fstrnyou]

Both cams have the same P/N from 2006-2013

[Solarsurge]

P0335 Crank Position Sensor A Circuit Malfunction

There's literally a step by step diagnostic guide on the forums for this.

[jlr8185]

if using tuning software or a AP, i would check the MAF voltages and make sure you didnt give voltages for too low a value. i know somewhere in the forums it talks about a minimum limit to which the MAF volts can go and anything voltages above 0 (zero) in that table below the minimum results in error code. happened to me a few times.

[Fstrnyou]

I want to say all MAF values below 0.9v should be zero.

[Djohns]

Don’t forget the ground by the fuel pump. Everyone forgets that one.

[ZoomZoomT]

When i was replacing my vvt and timing chain, after I put everything back together i had same thing with the crank but no start and that engine code. Turns out i forgot to plug in my crankshaft sensor. lol