I have a newly built 346 and yesterday I started having problems. When I get over 2500 rpms, it stumbles very bad and it has no pulling power. It idles fine though.

Please help!!!!

 

to tha top...

 

That doesn't sound like an internal engine problem to me. If something was broken inside it wouldn't idle right from my experience. I would look more toward tune, electrical problem like the maf sensor, or throttle position sensor. Those sensors will do weird things to the way your car will run if they arn't responding correctly. Just some ideas.

 

Check the MAF, O2's and all electrical connections.
Make sure you don't have a vacuum leak.
Then work on the tune.

 

How about fuel pump? Here is a vid. When I give it throttle, it drops in pressure...

http://s76.photobucket.com/albums/j3...nt=fuel001.flv

O, and when this issue happens, the car runs really lean and the temps rise...

 

It looks like it could be a fuel pump issue. I would grab a new fuel pump and at the same time take a look at your fuel filter to make sure its not clogged up.

 

That gauge was doing some crazy **** there for awhile, Id do fuel pump as well.

 

What injectors do you have?

 

they are 38lbs. I did replace the fuel filter and it did not help. BUT, I drove the car today and it is perfectly fine. I will try to drive it work tomorrow. I am still getting a pump to be on the safe side. it has 17x,xxx miles on it!

 

It was the pump. I got a Ractronics and it is A OK now!