We tried loading a tune on it from a car w/ a very similar setup. Only difference was a vic jr intake/accufab throttle body....I have a ported fast/NW 90mm....No luck on that attempt either.

 

Thats weird as hell. How long did it stay running when it first fired up?

 

Both times it ran for about 5 to 10 sec. Then it shut off (on its own) and never fired up again...It honestly doesn't even really sound like it is trying to hit, just cranking.

 

Did you give it some throttle while you tried to crank it or when it was running to keep it running?

 

where are you located?

 

Did you torque down the rockers to spec? Check your fuel pressure via Schrader valve and see if it's leaking down.

 

I have an electric fuel pressure gauge and a manual fuel pressure gauge right off the rail, both read 58-60 psi..... I am located in Springfield, MO. Tried putting and ecu out of another car in and replaced the crank sensor. Still no luck. At this point I am thinking it may be a faulty camshaft.....

 

That's a big cam for a stock cube motor and most certainly will require a retune. Anyway, you may have fouled the plugs from the constant cranking. I would replace them to make sure. Make sure you actually tune for your specific car instead of throwing in a canned tune and have a scan tool ready to log data.

 

Gotta be along the lines of a Cam sensor then.. It sounds like it's running off the fuel in the lines and something is not priming the system or something is shutting the pump off.. Did you plug the MAF in in the back of the intake?? The ECM must be loosing a crank signal somewhere.


Or else excessive valve train noise could be pulling timing, but that wouldn't cause a no start. It's not the rockers, and it's not the darn valve timing.. sometimes the BS answers on here leave me scratching my head.. There is no 'learn' cycle for these, it's almost instantaneous. OBD I had learning cycles.. But my H/C w/ no tune sometimes takes 30 seconds to get the idle back.

 

Yes, the MAP is secured in the back of the intake. The fuel pump holds a constant pressure at the rails as I have an electronic FP gauge in the car. I will replace the cam position sensor and give that a shot. Also, the plugs are brand new, but I may go ahead and replace them again just to elimate the possibility.... I agree w/ you, this whole situation has me "scratching my head." I have never had this much grief w/ a LS1 cam swap.....

 

On a side note, this cam was run for 500 miles or so in another 347 car and it ran fine w/ no issues. That is also the car that I pulled the ecu from to try in my car. For whatever reason, it is trying to be difficult in my car....

 

Was an identical powertrain? It wasn't a 98 computer was it?

 

It was an 01' car and the only difference was that he had a vic jr. vs. my ported FAST.