EFIDynoTuning Forum

I think some of the Trick Flow heads will comply for CA emission. Mine have the air injection fitting on either end that can be plugged if not used.

You won't regret buying good quality cylinder heads. If you don't have boost or nitrous good heads are the only way the engine can breath. They make a huge difference. Going from the worst head (the 86) to a nice flowing head, the Trick flow 170 gave me 100 HP increase.

This is gonna be awesome! Is there a turbo kit you'll be using or fab your own piping?

I think its more likely to be bent valves from the sound of it.

You probably know about this already but around that time there was an issue with the 4R100 mechanical diode. It may not be the year you have but I'm just saying to double check if you haven't already.

have you tried squirting some gas or staring fluid in there and see if it fires up for a second?

Try starting fluid in the throttle? If it fires on that it points to a fuel problem. 20 psi is too low As D said. You could have a weak pump and stuck injectors from sitting / gummed up.

I think most cars won't test evap if the fuel tank is near full or near empty. The sweet spot is around 80% - 20% full.
The cat monitor typically requires a long steady cruise with minimal hills.

I see the appeal of lots of gears and close ratios. That said there can be huge performance gains from finding the best torque convertor for your application. The modern gurus out there can tune the convertor to be loose to build rpm, then it tightens up as the engine reaches peak power to slingshot the car forward. I'm not saying it's a cure-all but something to consider.

The Buick GN engine has a long cranking time compared to the 5.0. It has sfi with a crank sensor and cam sensor and it waits till it sees #1. Smart using batch fire to light it on ours.