92 S13 Rough starting when cold...

[skydragoness]

I've noticed since September that the first start in the morning is rougher than it should be. The colder it is outside the more cranks it takes before it fully starts.Used to start up right away regardless of temps last winter... and we had a bitter winter.It also bucks/hesitates in the lower gears when it's cold as well. When the transmission and engine are warm, car is just dandy.

So a list of things already done: battery is new, starter is from a 240sx w/ 160k so I assume it's relatively new (not to mention it would've died on me by now if it were the starter)

Fuel filter, plugs (NGK v-power--if that matters), wires, are all from last fall. I cleaned my maf, cleaned the contacts on the plug hooked up to the MAF, cleaned the contacts for the distributor. Haven't cleaned the contacts on the injectors yet.

Recent work done, in late September: clutch, spec lightweight flywheel, dc sports header, new O2 sensor.

So any ideas of what I should address? I picked up a new set of v-power plugs and put them in. Still doing the same thing.

Any ideas of what else I should try looking for? I'm leaning towards checking out the fuel pump but was wondering if my car is displaying 'classic' symptoms or not.

p.s. If anyone thinks it's the ethanol crap in the fuel, i put a bottle of dry-gas in the tank once a month or more.

[rogoman]

There is a device mounted on the engine called an air regulator which islocated on the passenger's side of the engine, near the back, below theintake manifold. When the engine is cold and idling, the air regulatorallows additional air to flow to the engine thus maintaining a good idle.There's a good chance the air regulator is defective or the electricalconnections are bad.

Here's a picture: