I'm tryin to help a buddy of mine figure out various problems he's having with his TPI vortec headed LT4 hot cammed 350.

It's got a really bad startup (hard to start).
An extremely rough idle.
Gets HORRIABLE gas mileage.
And isn't running as strong as it should at all.

I know he's in need of some serious chip tuning amongst other things.

Now, my question is...When you turn the key and the pump primes, it primes to 40PSI. And after about 2-3 min the pressure drops to 30psi and then from there slowly drops. Isn't that an indication of leaky injector(s)? Cuz if i remember correctly...it should hold that constant pressure for quite some time before it starts to bleed down like that?

Thanks in advance!

 

Anyone?!?!

 

Not neccessarily, it could be caused by a faulty fuel pressure regulator, fuel pump check valve, leaking pulsator on fuel pump line, leaky injectors. You could have a bad coolant temp sensor for the hard start, do you have any trouble codes in the computer?