Hard start issue??

[hilltopfarm]

I have a 03' Ranger 4.0L & ever since putting a new engine/trans/t-case in it it has had a hard time starting. This only happens AFTER the first start of the day, it will crank over for 5-7 seconds and then start. I had it in the shop and the tech there put a fuel pressure gauge on it overnight thinking that it was a leakdown of the fuel pressure, but he said he could not replicate it... any ideas?? Should I get a fuel pressure gauge myself and monitor it to verify whether it is leaking down? I would think if that were the case, then priming it 3-4 times before starting would solve it, but it does not.

Thanks for any help!
-Anthony

 

[hilltopfarm]

Any thoughts anyone? Anybody had a similar issue?