V1 New problem. Cranks but wont start. Backfires

[Oldchevyguy]

I just got thus on the road. I drove to a gas station to fill it up. It leaked outvthe top, so I guess the fuel pump gasket isn't set right. But the purpose of this post is the no start. I had to get it towed back by a good samaritan. Only a mile away. It backfires very loudly through the exhaust when cranking. The cam sensor is new for the same reason btw. Any ideas?

 

[Murcielago311]

What method did you use to align your new cam sensor? I have read conflicting instructions for where to set TDC for aligning the CPS timing marks.

 

[Oldchevyguy]

Checking on this. Will get back to you.

 

[Vwsaabvt]

remember this?

How did you time your can sensor housing when you put it back on? Tdc compression stroke on 1 or 4 I've seen both mentioned.

Also found this looking around after I took mine off

https://www.cobaltss.net/forums/problems-service-maintenance-69/lsj-cmp-housing-seal-p0017-326802/

I didnt turn it inside, and put it back on the same way it was. Haven't tried to start it yet. We will see. If it doesn't run I'll search the procedure.

 

[Murcielago311]

I initially re-installed mine thinking I'll just put it in the same position it came out, but then I realized that the hex head inside the CPS likes to rotate on it's own. So I pulled it back off, removed the sensor that plugs into the CPS, then you can stick your finger through the sensor port to hold the hex head in place while you reinsert the CPS. I timed everything to TDC on cyl 1, based on the most convincing how-to on the cobalt forum. I'll find out this weekend if that's right. If not, there are only six possible positions of the hex head, so you could just rotate to next spot until it starts and runs.

 

[Torchandregdoc]

Check fuel pressure. Low fuel pressure will slobber fuel instead of atomizing fuel and they do weird things.

 

[Oldchevyguy]

Ok. I drove it 6 Miles now. I am calling it fixed. The cam sensor housing was not timed right. Here is the procedure.
Take out # FOUR (NOT ONE) sparkplug. Find top dead center compression by bumping over and I used a tool that had a air tube so you could feel air escaping when the piston comes up. You might be able to just stick your finger in, but it's a long way down, and my hand is big.
Align the timing Mark's on the front balancer and chain cover. It should be close.
Now remove the housing, if it's not already off. I used a plastic cap that comes on a hydraulic hose, shaved down, on the cam sensor to lock the housing gears from turning. Align the Mark's on that. One on the shaft. One on the housing. Now reinstall, and remove the plastic cap. Reinstall the cam sensor. Some people stick there finger in the hole to hold the it. That was too hard for me. Engine was installed, and aforementioned big fingers.
Now it runs perfect. Dosen't backfire like it did before on starts sometimes. And no code for cam sensor out of phase.

 

[Murcielago311]

So just to confirm, the cylinder at TDC was the one closest to the transmission?

 

[Oldchevyguy]

So just to confirm, the cylinder at TDC was the one closest to the transmission?

Yes

 

[Oldchevyguy]

I drove the car today over 30 miles at all different road speeds and all is good!