LT1 sputters under acceleration

I have a 95 Formula with the LT1, Automatic, 144,000 miles.
I have been getting bad gas mileage for quite sometime (i.e.11 hwy). The car became hard to cold start about a month ago. It started fine when warm and seemed to run ok though. Today the car is very hard to start it takes about 10-15 seconds of cranking before it grabs. The car idles fine and sounds completely normal idling. But when you put it into gear it sputters and you cant go above about 2k rpms or it sputters and dies.

I scanned the car and got MAF circuit, and EVAP purge solenoid codes. I cleaned the MAF with CRC maf sensor cleaner. I also unhooked it to see what would happen and the car still sputters with the MAF unplugged. I had new plugs and wires, PCV and air filter put in about 4k miles ago. So I assume that the problem is fuel related, I have not had the fuel pressure tested but the car smells strongly of gas. Could it be the OPTI?

I need help with this one, Any ideas?
Thanks, Dave

I would check your fuel pressure first changing the optispark can somtimes be a pain...

Youre on 144K miles and original opti? That's a miracle in itself.

I got the car from a dealership with 102K on it, and as far as I know its the original Opti.

Sounds like time for a new opti.

I started it today and drove around the block. It will rev fine without any sputter while in park or neutral. When you put it in any drive gear it will take off somewhat ok in 1st, but 2nd and above the car will not rev above 2k rpms without sputtering, backfiring and cutting out. I sprayed brake cleaner on all the vaccum lines and found no leaks. It could still be a vaccuum leak though. Any ideas?

My gta did that at 15000 miles. Pontiac said nothings wrong. New injectors sensors u name it i put it on. Finally put fuel pump n that was my fix. Pontiac checked fuel pressure and assured me pump was good.Shows how qualified they r at 85 buks an hour.. They gave me my money back..