One and only remaining problem with my car that I'm trying to get corrected.

What happens is off a cold start it will idle rough and hesitate if you give it gas. The problem gradually improves as the engine warms up until about 5 - 10 minutes later and It's totally gone. If you shut the car off and start it back up while the engine is still hot it does not happen. If you allow it to cool off a little bit it will hesitate a hair upon restart but then goes away. If you allow it to cool completely down IE overnight then the problem is full blown again on the next restart. It's as if whatever is causing this is fixed by heatsoak. The condition will become gradually worse directly proportional to how much you allow the engine to cool down and vice versa.

FYI This is a rebuilt longblock with only 15k miles. EVERY sensor except for the knock and Thermal-Time switch have been replaced with new parts. MAF, IAC, IAT, CTS and TPS are all new and within proper specs. I also just changed the spark plugs and replaced the FPR with an adjustable holley unit since the stock diaphragm was crumbling apart. Current fuel pressure is 43 PSI until I can get it the track this wednesday and find out what it likes best.

The car runs like a champ once It's had It's "Morning coffee". I'm asking all the experienced TPI guys out there if you believe it is the injectors in need of a good clean and flow that could be causing this. The only other thing that is not properly tuned ATM is I found out my base timing is retarded by 2* (Currently at 4* BTDC) which I am going to correct as soon as we have a sunny day here, but I somehow don't believe it could be causing this problem.