HHR not wanting to start after engine replacement
 

We just got a 2011 HHR from an auction. We got an extra engine with it. Both engine needed work. It turns out that the engine that came in it after being worked on would not start. The second engine only had a good crankshaft so we kept that. Anybody have any ideas why it wouldn't start

Welcome to the site, possibly the crank sensor or dead battery or loose or broken ground wires

............. or dead fuel pump, bad sensor (too many to list), bad ECM etc. etc.. Without a list of things you have already checked, anything we can offer would be a wild guess.

Have you checked to see if it is getting fuel? How about spark? Done a compression check?

What is no start? Does it crank? If so: fast, slow, normal? Got spark? Fuel in tank(yes it happens)? Key matched to car/ECU?

I think the crank sensor has to be learned if swapped.

The crank sensor needs to be learned but will not prevent a start if not learned, just a CEL.

Are the ECM, BCM, sensors and injectors all matched?

Should we assume that you know what you are doing or that you are a novice re: modern computerized cars.

:lol::thumb:Turns out the key we got needed programed(knew that). But then the car still would not start so had to mess with the electrical system in the front. In the end it was something that we had never touched or messed with that dealt with the battery and grounds.

As mentioned in post #2! Yeah, it lives!!

Runs Real Smooth now. Love the quietness and limited road noise. The turn signal sound is pretty cool.