Hello...was running fine one day. Sat for a couple of days and will not crank since...4 weeks of trying. No oil or coolant cross-contamination, and both are full. Battery freshly charged. I've tried it with throttle pedal all the way down, pumping midway, as well as untouched. Air filter is clean and I cleaned the throttle body and MAF sensor. Fuses are all good. I've also tried spraying starter fluid into the intake manifold...still no change.

I checked codes and these are present:
P0171 (freeze frame data attached)
P0401
P0431
P0421

Does anyone have any suggestions where to start and how? I've got a test light and voltmeter.
Thanks!

 

Can you please clarify - does engine CRANK and NOT START, or does it NOT CRANK at all?
Those are two very different conditions. I don't believe any of the codes you've posted cause the non start condition.
If it cranks, you need to check if you're getting spark and fuel and compression before moving any further

 

Hello. Thanks. It cranks but will not start.
Is there an easy way to check spark on all 6 wires without removing a bunch of crap like the intake manifold?

Is there an easy location to break into the fuel line and see if fuel comes out when the key is turned to position 1 or 2?

If the cam sensor was bad would it toss a code?

Compression will come last, if necessary.




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You can plug an inline spark tester right at the coil where wire starts. Cranking the engine will show if you got spark on that coil. Doing it once per coil will show presence if spark on two cylinders (no need to test both ends of coil).

High pressure fuel line comes via a metal pipe from firewall and connects through the flare nut to a rubber hose which then goes to the front of fuel rail. Just disconnecting it will not tell you if you have right fuel pressure and required flow amount, just that it "pumps" when key on and/or cranking. You are going to spill a bunch of fuel all over the place, so you best have a helper and couple of fire extinguishers within reach if you're going to do this.

Faulty crank and/or cam position sensor could set a code, but NOT if you already got bunh of othet codes flashing. You can check if sensor works by unplugging connector and testing the siglsl wire while turning crankshaft by hand. The signal should change every 30 degrees from ON to OFF

 

Thanks! Will check cam and crank sensors next.

FYI...maybe no need to crank motor by hand to check cam/crank sensors.

A YouTuber named ScannerDanner shows if you want to test the cam and cranks sensors are giving inputs to the PCM/computer that you can test the wires at any of the fuel injector plugs. If one flashes with a test light as someone cranks ignition they are good because the computer is sending a fuel injection signal.

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ScannerSanner is the BEST electrical diagnosticians out there. Definitely try his method if you got the tools he is using.