I'll do that and see what happens after I verify there are no vacuum leaks. Would an uncalibrated MAF cause the long cranking cold starts? Even when it was dead cold out, the old L27 would fire up in no time. Just wondering if that has anything to do with it.

The more I read around, the more I realize that my fuel pressure regulator might not be the problem. Seems that people are getting as low as 46psi at idle. I'm just concerned with how long it takes to crank.

Shouldn't everything run "better" if I disconnect the MAF and let the car run in speed density mode?

No, things aren't better when the computer is assuming the air based on tables instead of actual flow.

Clearly you are lean. Now let'* talk about what'* been done.
What injectors are in the engine?
What injector table is in the tune?
Get those two straightened out first. Then let'* figure out where the VE and maf are for tuning.

What maf are you running and which maf table is in your tune?

BTW if you are ever looking for a large vacuum leak, pull the EGR to LIM tube. That'* one of the most common and impossible to test with a can of carb cleaner leaks out there.

That will depend on your VE tables. It will take a bit to smooth out. I don't suspect a bad MAF, just a bad MAF curve.

If you put the right injector table in, the pressure they are rated for wont be a issue. If a injector is a 30# @ 36psi injector that is what it is. If your at 45# fuel pressure they will provide more fuel, not less, also, seeing he'* lean in only one area, I don't suspect injectors. But still a good idea to make sure they are right.

The injectors are the stock injectors from a 2000 regal GS, which is where this motor came out of.
The injector table was posted on page 1 in one of my posts. It starts at 36.x at 0kpa and goes to 38.x at 100kpa.

The MAF is from an L36. I was told that there is no difference between an L67 and L36 MAF. They seem to be the same part number everywhere. The MAF tune is from an L67.

That EGR tube is a GREAT idea. I was actually thinking of that a little while ago. I'll have to pull that off to check if its a possible problem, which it definitely could be.

Right, but even a bad maf curve would allow the car to start up quickly and not crank for 4 seconds.

Yeah, under light to moderate acceleration the LTFTs actually shift into the other direction and its pretty clear that the car is not running lean. I'm going to verify that there are no vacuum leaks and that the EGR tube is good. Tuning around mechanical issues is a bad idea.

OK, so what injector table is that? I'm not about to go hunting through tunes to try and figure it out. It should have come from another tune and been put into your tune.

I only know so much about what tune is on this car. I have absolutely no idea what the stock L67 tune. All I know is that this is my injector mapping:

36.09549 36.51102 37.02563 37.75668 37.91079 37.98831 38.04389 38.09962 38.14432 38.27907 38.40343

My entire tune was taken from a guy who also has a Regal with the exact same modifications as mine, so it was supposed to just work. Obviously that'* not the case.

A tune is not a one size fits all, sorry. With the same setup you will be close, but you really need to go over things.

So, I'm to assume his setup has the same injectors as yours. If so then I really don't feel it'* the injector table. At idle your running mainly off the MAF curve for setting the AFR, the PE table is not involved. You can unplug the MAF and then watch your LTFT and see if that helps any, if so, then it'* your MAF curve. Also, compare your idle scan to his idle scan.

Right, I know that a tune is not one size fits all. I know that every engine is different, and that I would need to go over everything once I got this tune in. However, I did at least expect it to hold a correct idle given we have the same modifications.

I'll try to unplug the MAF and see what happens. If nothing changes, that EGR tube might be cracked or leaking, or who knows what.