1st Gen R53 Cooper S Replaced oil pan gasket; now no oil pressure, low rpm and rough idle

You guys are going to think I'm nuts after posting this... Oh well here we go.

I picked up a '05 R53 with 80k miles. Good running car but petty drastic oil pan leak. I R&R the oil pan gasket and while there changed crank sensor gasket and a leaking thermostat gasket. It was a chore! Ugh. New oil, 5w30 royal purple. Refreshed coolant.

I went to start the car and not good! It starts but really rough, no pedal, no oil pressure, and low, almost stalling engine! Even with pedal on the floor. WTH??

Plan to recheck my connections again but looking for guidance or similar experiences.

On my mind at the moment :idea:, maybe in order of hope :fingerscrossed:
1. It's cold, battery (and car) need to run for a few...
2. It's not leaking oil, so oil gasket replacement ok. I've read others resetting CEL which I didn't do. Does that matter?
3. Air and fuel mix. I did clean air filter maybe it's restrictive with PJ1. I've used this before on foam air filters. I'll pull that off and see if that helps. Additionally recheck the fuel bits that needed to be disconnected to remove serpentine belt. Maybe another vacuum hose some where?
4. I screwed up the crankshaft sensor when R&R? That would suck! But ok.

Agains thanks for any guidance. I post updates later.

 

Metalman your brilliant! Grey plastic pipe wasn't seated all the way on the MAP sensor and after reseating bam. Still not reading any oil pressure - when I rest on accelerator the light will go off around 3k rpm... then back on if I let off. maybe the filter housing isn't on right??

 

Unfortunately I found the problem to my engine oil light :mad2:
http://new.minimania.com/images/articles/filter_base.jpg

Drain back plunger came out with the filter while trouble shooting.

Bentley doesn't even show this in their book (at least I can't find it) so looking for DIY guide if its out there. May create one if not

 

thanks. Its going to be a chore... tried getting in there to assess the effort. stupid tight and messy... so far.

 

found this: North American Motoring - View Single Post - Oil pressure relief valve

I'll attempt this first then dig deeper if it doesn't work.

 

Way you might have just made my week. I just ordered a new gasket and oil radiator seals from you in anticipation of pulling that housing out. If your saying you have a few of those black drain plungers available I'll take one!