LT1 383 Hard Start

I just finished building my 383 for my car and im having problems starting the car. When the car is cool, I have to hit the gas in order to get in running. After it starts i have to pump the gas until it
warms up (maybe 30 sec or so) During this time the engine runs rough and misses. after the engine is warm it runs fine. When the engine is warm the gas still needs to be hit, but only some of the time to get it running and it will take only a couple sec to get the car running well. Does any one have any ideas?
Performance upgrades Eagle 383 stroker kit, LE1 Heads, Comp Cam Camshaft Roller Rocker tips and Push Rods. Fel Pro head gasket, 37lb injectors, Mad tuner ECU tune, Transgo shift kit, Fuddel 3000 stall, 255 walbro fuel pump.
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Any one???
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Any time significant changes have been made to the engine you need to get the computer reprogrammed with the proper maps for the new engine configuration (once it hits closed loop it no longer matters and the computer will automatically adjust to the different fuel and air requirements) as the fuel mixture and airflow requirements are different. The computer is programmed with preset levels for until the engine warms up so the sensors are providing valid data for the computer to adjust the engine to. I'm not sure where you would find the proper programming, but I would guess that most performance shops would be able to do that programming for you.
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Cy Welch
Senior Programmer/Analyst
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wrote:

"Mad tuner ECU tune"( ECU has been tuned) Also it still has the same problem if its in open or closed loop. The only thing is that the car runs well after the engine warms up. Not enough to put it in close loop, it only takes about 20 sec or so after a cold start for the engine to run well.
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Tonny, did it perform well before the re-build? And have you have it analyzed for codes since rebuild and problems showing up? s
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Another idea: do you still have the cats and O2 sensors installed? And is the "air tube(?)" from rear center of engine to the front (runs along left-of-center looking from front of engine) still attached and not leaking? It looks to be a plug-off-and-throw-away part, but not so! Learned from experience putting LT-1 in a Studebaker pickup! s
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I'm quitting now for awhile, but: what is the fuel pressure at the rails now? s
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Checked for Vac leaks ?
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Terminal_Crazy

Mitch - 1995 Z28 LT1 M6 terminal snipped-for-privacy@sand-hill.freeserve.co.uk
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