This weekend I did the LS1 to LS6 intake manifold swap. Now, this wasn't a complicated project, nor did it take too long. But, after the cam swap, my car is having a hard time turning. The engine fires and then shuts off after about 2 to 3 seconds.

I have checked and rechecked all connections and made sure everything was plugged in correctly. I also looked for any pinched hoses or cables, but didn't find any. I'm honestly confused, and my last step is really to disconnect everything, including the intake manifold from the block, and basically start over.

Anybody have any ideas????

 

did you plug in the sensor in the back of the intake? Or my best guess is intake leak.

 

Leak or unplugged sensor. May need to check the sensors there in the back of the manifold.

 

Make sure all vacuum lines are plugged in (one small in back of manifold, one big in back of manifold, MAP sensor in back of manifold...plus the lines in the front and TB).

Are all of the bolts torqued down? Did you make sure to transfer your intake port and throttle body gaskets from your old intake to your new one (if the new one didn't come with gaskets)?

 

Sounds like when you replaced cam that your valve adjustment is off.

 

Sounds like a VATS issue.

 

VATS shouldn't allow the car to even fire though, correct? I know that's how it is on the earlier versions of VATS (read later thirdgens).

 

I am going with this idea. Sounds like the DOT to DOT is off.

 

When I swapped in my '01 motor, the VATS was not turned off in the PCM and mine behaved exactly like this. i.e. ran for a few seconds then cut off.

 

Hmm odd....I'm also confused as to why people are mentioning cam stuff....didn't he just change the intake manifold and nothing else?!

 

I believe he said he did a cam swap.

 

It wasn't real clear as to how the car was running and which mod "caused" the problem.

I say "caused" as there could have been a new problem induced by doing the mod, but not the mods fault.

 

Did you make sure you seated your fuel rail back completely in the new manifold with the injectors. Are there any loose connections on any of your injectors? Hose leak maybe? You didn't by accident, drop something down one of your ports?

 

Oh damnit, I read that first post at least six or seven times trying to figure out why you guys were mentioning cam stuff, and I overlooked that line completely.

 

I think he forget to top off his blinker fluid or rotate his muffler bearings.

 

I like the VATS idea too....Ive done a conversion on a stang and it did the same thing described here.

 

Sorry for the confusing guys. It was simply an LS1 intake manifold to LS6 intake manifold swap. Nothing else was replaced.

I'll have to look over my engine over the weekend and follow on your advice guys.

Thanks