Loktai

So I've got this 92 Sentra, and it developed this problem recently which was, that it would start ok if left to sit, but would die unless you got your foot right on the gas, if you did not, it would stall and not start UNLESS you pull the fuel pump fuse and crank for a while, rev it up and stick the fuel pump fuse back in (amazing what you figure out when you need to get to work).

If you keep your foot on the gas , it'll rev up and miss a bit and be choppy but eventually (within 30 seconds I'd say ) smooth out. and the longer you drive /run it the better it gets, until its 100% normal, at first it idles high, and tries to die/rpms drop if you hit the gas, unless you hit it hard then it just hesitates and revs up ok, but once its fully warmed up etc there is no hesitation, it idles at like 800rpm ( and overall smooth/normal for a 92 sentra)and is fine. Once its warmed up like this, it can sit an hour or two , you start it up, and its fine. But you let it sit a long time, and it once again needs to be revved up and go through the BS agian until it evens out.

SINCE the problem, I figured okay maybe vacuum leak, so I replaced all of my small ,and most of my larger vacuum/pcv hoses, and put on an intake pipe with a new cone filter,... NO change, same symptoms, authough the overall idle/smoothness/power did increase of corse with those changes. What else could cause this? I did put a bit of seafoam in my tank a few weeks ago, because I just got this car a few months ago and it sat a bit before I got it on the road, figured it could use a cleaning out. I've been through a few tanks of gas since. It never had this problem before, authough I must note the cold weather has just recently set in. I am not getting any Check engine light. ANY IDEAS? I was thinking since it goes away when it warms up it could be some kind of temp sensor? But I am not very familiar with these cars yet and honestly I dont want to bark up the wrong tree , any reasons why it could / couldnt be the coolant temp sensor or any other suggestions to why it would be 100% perfect when warm and crappy/choppy/stalling when first started, or why it might be getting flooded on cold start?