Car: 08 Cobalt SS/TC
Mods: Mitsubishi 20g, synapse piping and intercooler, Hahn CAI, synapse catless downpipe, full 3" exhaust, HP tuned.

Ok so here's the story. I got into a collision in march where my drivers side of the core support and part of the frame was crushed in. I had a body shop take it in to fix it. When I got the car back from the body shop. I noticed it would crank start up for about 1/2 a second and die. After a couple more starts the car ran fine so I assumed the ethanol in the fuel system was breaking down causing the problem. A couple of days later I filled up and drove on new fuel and the car still continued to act up starting and was starting to take a couple more starts each day to get it to run. I took it to my tuner to have them look at it. They noticed I had a ground cable off that the body shop forgot to put it back on. Put it back on started up first try. Drove it home, went to sleep came back when I woke up to start it and the starting problem was back. I attempted to start it approx. 15 tries before I gave up and drove my parent's car. I was only throwing a code p0101 which I know was related to my tune and that I had a couple of tiny boost leaks on the intercooler from the wreck. I put the stock intercooler back on, the car now continues to crank and start for 1/2 a sec, then die, then the starter tries to crank it again until the timer on the starter stops and I have to turn the key again. Now I'm throwing codes for p0336(crankshaft sensor), I cleared that code started up and started fine so I assumed everything was back in order except for the tune of course. woke up this morning went to crank and THE PROBLEM CAME RIGHT BACK. I haven't seen the p0101 yet but I'm sure its because I haven't driven the car yet but the p0336 code continues to come back. I need input please. I have read everyone's post to the 0101 code, and I couldn't find much on the 0336 code on here. Any input would be greatly appreciated! The car hasn't started and ran since yesterday evening and we have cranked the car a total of 40 times through trial and error with no luck. No vaccum leaks on any of the lines.

 

Bump! anybody?

 

bump

 

Look for any big boost leaks in the charge piping.

 

I suggest lookin at the crankshaft sensor..computers dont throw codes for no reason

 

either not plugged in, bad, or wire cut on the sensor. that would be the only reason the code would come right back after clearing

 

Ahh, yeah. I didn't see the p0336 you mentioned. Either damaged your sensor or harness to the crank sensor.

 

The engine cranks but wouldn't fire up?

 

If you can't clear the code ie it's a hard code definitely a electrical issue it's prolly not plugged in or the harness is damaged do you get a good steady rpm reading ?

 

No boost leaks for sure. Only things that was leaking was the intercooler and i put the stock one back on. I get a jump from the rpm gauge when its fires up for the 1/2 a second but it dies along with the motor shortly after. I looked at the case and its plugged in and intact still. I can't see any wiring harness problems but its just the space in the engine bay. Im going to do a voltmeter test on it tomorrow and see any differences.

 

It's a long shot but could it be your fuse box/fuses. Mind's had stalling and intermittent will not crank over issues. GM replaced with a new fuse box and things are ok since then. GL

 

Mine did something similar this morning. Car cranked, drove it and got gas, went to crank it and would turn over but not fire. The started would rapidly and repeatedly try to start the car. I tried 3 different times before I decided to give it gas. Cranked and died. Repeated but kept my foot on the pedal, put it in gear, and drove off. Its been fine since then. Threw a code but I've yet to check it since the last time I used an obd2 it screwed my tune file

 

Yours is probably your evap purge solenoid. Its a common problem at the pump. just replace the solenoid and you should be golden. Update:

I replaced the Crankshaft sensor today thinking it went bad. No Change. I'm starting to think VCM? what do you all think?

 

Have your tuner do a crank relearn on it. Might clear it up. If the sensor gets unplugged or the computer loses power for an extended period of time the computer will get all fussy like a virgin getting her pants unzipped... no, no don't turn me on... crank relearn and cue the Barry White music... ohhhh yeaaaaaa

 

I've got to get the car to start first. Doesn't it have to be up to operating tempature to do the crank relearn?

 

Update:

I got her fixed!!!! turns out where the ground cable was placed was a bad ground because it was on the new framerail that was welded to the body. Extended the cable to the other side of the frame and wha la!!! Thanks for everyone's input!

 

Oh thats good! Seems like an obvious answer too haha I hate when its that simple and you just cant put your finger on it. The new frame rail must make a bad connection for the ground.