Swap Issue

['72 Pro Street]

Hi All,
I am having a problem with my truck after swapping in a 03 5.3L. I have around 700 -800 miles on it now and this issue showed up in the last 100 miles or so. The truck will not start on the first try it just spins and doesn't act like it is firing. I can shut the key off and then try again most of the time it won't start again but will backfire out of the exhaust. On the third time it will usually start. I am getting a code for cam position sensor(P0343) and lean condition(P0171,P0174). I have replaced the cam position sensor and it acts the same. I have done some research and seen were some people were having problems with the cam bolts coming loose. I took the cover off and check them and they are tight. The timing chain seemed a little loose but from what have read that is pretty normal. Just wondering if anyone has any ideals on what it could be? After it starts it seems to run just fine. Sorry for the long just trying to give as information as I can. Thanks John

[Blackpony]

I would check the wiring and connectors. Sometimes they can be getting a bad connection and cause problems.

['72 Pro Street]

Ok I was thinking about doing that. It is a new harness but I will check it out and make sure they look ok. Thanks for the reply!

[BR3W CITY]

Is the engine cammed?

Try doing a CASE relearn. Search here or on LS1tech for the procedure. It puts the cam and crank sensors back into phase with each other, and should clear the code.

The lean condition may just be a side effect from the backfire. When you clear the codes and do the CASE relearn, I'm guessing it will go away on its own. If not, you may have 2 unrelated issues, but don't fret about that until you try the above first.

['72 Pro Street]

Originally Posted by BR3W CITY

Is the engine cammed?

Try doing a CASE relearn. Search here or on LS1tech for the procedure. It puts the cam and crank sensors back into phase with each other, and should clear the code.

The lean condition may just be a side effect from the backfire. When you clear the codes and do the CASE relearn, I'm guessing it will go away on its own. If not, you may have 2 unrelated issues, but don't fret about that until you try the above first.

No the engine is stock internals. Has shorty headers and a cold air intake on it. I will search for the CASE relearn and see if that helps me out. Thanks for info!

[Hart_Rod]

Case relearn should do the trick. Try this:

http://www.hptuners.com/forum/showth...earn+procedure

['72 Pro Street]

Originally Posted by Hart_Rod

Case relearn should do the trick. Try this:

http://www.hptuners.com/forum/showth...earn+procedure

Ok looks like I need to find someone with tuning software to do it. I will ask around work and see if someone knows anyone that can do it for me. Thanks for the link.