Lopey cold start?replaced everything?3.6L

I�ve thrown everything at this and it�s still around. Worth noting, I have a tune and the SAI is deleted. Initially that seemed to solve the problem, then a few weeks later it started happening again. It turns over immediately, sits at 1200 RPM for a second, then momentarily drops to ~700 rpm jumps to 1k, then will just be lopey. If I sit there for about 30 seconds it�ll eventually smooth out or I can give it some throttle and it�ll hesitate but will smoothen out after a few light revs and then no longer hesitate when smoothed out. If I try to drive away when it�s lopey I have to feather the clutch and/or keep the revs up. It�s hit or miss if it�s jerky after the clutch is let out all the way and I try to just slowly take off�it�s fine if I just give it the beans to take off. What�s been replaced (all OEM): MAF Coils Plugs Air Filter all 4 O2 sensors I�ve also recalibrated the throttle so I don�t think it�s that. Any ideas here?

Check your fuel trims, and follow up with a smoke test if your car is running lean.

Can I check fuel trims with the Por II? I would just hook it up, but my unit is in my storage unit about an hour away Would I be looking at short or long term?

Yes, I think the Por II is the proper tool for the job. Ideally, you�d use that over a generic OBD2 scanner. When you mention short- and long-term fuel trims, I suppose you�re talking about a generic OBD2 scanner. If you can get ahold of your Por II, here�s a good video that can explain fuel trims better than I can. https://m.youtube.com/watch?si=SWENt...ature=youtu.be If it�s too much effort to get your Por II, you could skip the fuel trim check and jump into smoke testing it.

Alright, go ahold of my PORII. Although there's no CEL, the codes it stored were: P0300 Random multiple cylinder misfire detected P0302 Cylinder 2 misfire P0303 Cylinder 3 misfire P0301 Cylinder 1 misfire Fuel trims for whatever never gave any readings in bank 1 or 2, it just read 0.0% for one of the bank/side readings. There was another reading and it read at 99.2% for both. These are the readings when cold, once the rpms came down from the cold start, the rpms are steady-ish aroun 700-800 rpm and absolute throttle positions changes to 3.9%, otherwise, the other values are the same. I've attached the pics below: As luck would have it, the hesitiation didn't happen as badly this time, but it did have the slight hesitation/misfire a few seconds later, but I was too busy looking at the PORii to look at the data to also film lol. Here's a video of the idle after the coldstart rpms come down to the regular idle speed of around 800rpm; it's warm here so the higher RPMs only lasted about 10-15 seconds. You can see the idle is mostly smooth at this point. It is completely smooth once the car reaches ~180*. You can also see there's a bit of hesitation/misfire if I blip the throttle.....but if I hold the throttle, it's smooth. This hesitation when blipping goes away completely once the car is warmed up to ~180. You Tube Any insight from this? I'm starting to think there's a leaky injector where after the car shuts off, like perhaps there's excess fuel in the cylinder or something since the symptoms start to go away as it warms up and completely goes away when it's close to op temp as opposed to get worse if it were a vacuum leak. Just thinking outloud. Thoughts?

Replaced the crankshaft position sensor yesterday. Started the car up, ran better, no lopes, no stored misfire codes�drove strong. I went to start it this morning and while it ran better, it did still have the lope to it, just not quite as prominent. It also went away much sooner. Typically it would take getting near op temp to go away, now it�s gone by the time I get down the street. Also connected it to the PORII and there was no stored codes from yesterday or from the lopey cold start after I got to work this morning�. So, air temp sensor next? After that, then what? Injectors? What kind of vacuum leak would go away when warming up? Vacuum leaks get worse as the car warms up�typically atleast lol

As an update, turns out it was a combination of things. The tune from FVD was not good. It was the meat of the issue. It appears as if they didn't use a base map from an X51 engine, rather just a generic carrera and adjusted it. Hence the reason for it progressively getting worse as the ECU over time wasn't managing adjustments properly. We verified this as being a large peice of the pie as the car ran significantly better before replacing the exhaust and injectors. SMALL exhaust leak. I replaced my headers, xpipe, and mufflers with a new Soul exhaust. That was going to happen anyways, but when fabricating the Soul exhaust and removing the FVD xpipe and fabspeed mufflers, we noticed a few small exhaust leaks. One on the passenger bank at the header collector, and one on each of the muffler to xpipe joints. The accuseal clamps eventually gave way just enough from poor fitment to start leaking. One of the injectors was leaking and two of the other injectors weren't flowing consistenly. I replaced all the injectors and also had the tuner up my idle to 1050 per Slakker (the idle on these cars is apparently too low) and all the issues are gone. Gave the car a ~800 mile trip down to the dragon, 800 miles worth of hard driving while down there (hours at a time over 5k rpm), and the ~800 miles back and it ran flawlessly. This was quite the journey