Need some troubleshooting help guys. Suggestions are much appreciated!

Car had spark and all before engine was pulled, garage dropped cradle, swapped engines. Mechanic called and says cars getting fuel but won't start. Checked all stupid little things, like grounds.

Since the PCM was setup for the crank sensor on the other car, do I have to do the security relearn? Other than that, I'm assuming its something physically wrong.

 

Do a security relearn. It won't hurt to try.

 

Thanks, I just went down to check it out for myself. No security light at all, just cranks and cranks but won't start. He checked voltage on the Crankshaft sensor and said it is good, but he's willing to swap it out.

Its throwing codes 335 and 532 which are Crankshaft sensor and A/C pressure sensor.

If the sensor is no good, will the car not fire at all? If its not matched to the PCM, I'm aware of the case relearn. BUT would the car start, even if not matched to the PCM?

 

bad crank sensor will keep the engine from starting.

 

It will not start without the case relearn.

Swap it out, do the relearn, and give it a shot.

If nothing checks out, recheck all the grounds, connections. Trace everything.

 

is your pcm still in the car? or did you take the one from the other car?

also the crank sensor can be your issue.....is that the one off the new motor of your old one?

 

check the connector right above the master cylinder. Plug it in ....also you may have to do a CASE relearn because of the swap

 

I'm using my original PCM, it was reflashed back to stock by Intense. When installed with the blown engine, it fired right up.

He installed the used engine and left that Crankshaft sensor in. I'll have him swap it out tomorrow.

Thanks for the help! Any other suggestions, keep em coming.

 

is it even turning over? is the starter working properly?

 

double check the fuel pump relay to make sure its in the exact pins

 

Car cranks and cranks, but doesn't even cough or attempt to start.

 

ok so if you do an engine swap(which i'm in the middle of) do you need to do a case relearn or can you just swap out the crank position sensor and be on your way?

 

Most likely just the sensor as long as your using the same PCM which I don't see why one wouldn't.

 

OK question. If I go and buy/install a brand new cranshaft sensor, should the car run at all without a relearn?

I don't care if it runs shitty til I can get it to a dealer, just for troubleshooting sakes I'd like to know if it SHOULD start at all?

 

i dont see why you would have to do i case relearn anyway. same motor going back in right. i didnt miss the part were you swapped an ls1 ?

 

SALVAGE LSJ was installed, and its crankshaft sensor was left in. Running my original PCM.

 

The new crank sensor won't make the car start either. You need to swap it out AND do a case relearn.

Actually, do a case relearn as your using YOUR PCM and THE OTHER crank sensor.

 

if the crank sensor is bad and you replace it with a new/good cranksensor, the car will start and run when you put the new cranksensor in. It will throw a corrolation code and a code for variation not learned which is why you have to perform a cranshaft variation learn (case learn as people here call it)......if it didn't start how would we do a variation learn

 

Thanks sounds like you've done this, are you a tech?

I'll see if any dealers have a cranshaft sensor in stock tomorrow. If not, I'll see if the sensor from my original engine will at least get the car started. If it doesn't then I guess we can assume its something else.

I'm also going to try the security relearn for the hell of it. I don't know if its needed after an engine swap.

 

yes, I'm a tech. at a chevrolet cadillac dealership...... the security relean isn't needed, that's pretty much for your theft deterrent in your ignition system and all that. Shoot me a PM if you have any questions, I'll try and help you out

 

****, you got me.

Prop's to a tech jumping in here.

 

Double check all of your sensor plugs ins. I had the same problem because I switched the TB sensor and the sensor coming off of the spark plugs

 

What year was the salvage motor and what year is yours? They changed the number of crank sensor triggers on the reluctor in 07.

ps : r u still selling the turbo header.

 

My cobalt is an 05, I'm almost positive this isn't from an 07. Its the salvage engine Rogue from Intense had for sale on here. You were even interested in it. I better not have gotten a bunk motor!

Turbo header was sold, sorry.

 

Do the damn case relearn. 95% sure that is your problem. Also double check the cam sensor connections... other than that, I dunno what else it could be, but I had that happen to my car, did the case relearn and all was good