Rich Mixture, Misfire, Stalling

[SuspiciousPizza]

EA82, SPFI, 5MT D/R. 

My engine runs *okay* and can do short back an fourths to work alright.

However, it has a misfire. The entire throttle body (injector, TPS, and regulator included) is a "good used" part. My fuel pump is also noisy and I have no idea when it was last replaced. 

TPS is properly setup. Used the 2 feeler gauges. 

Once I've been driving for a while, sometimes it'll run like a top. Buttery smooth. Other times it idles rough. It doesn't buck the car side to side but it does vibrate. A noticable gas smell comes from the driver side and the plug for cylinder #4 has more carbon buildup.

I've had the engine stall 3 times after coasting to the bottom of a hill and pushing in the clutch. My guess is the rich mixture floods as I'm coasting and not burning all of it off. Then once I clutch in and the RPM's drop, the mixture is too rich and it just stalls. 

I've swapped in hotter plugs with a tighter gap, cleaned the MAF, and checked my timing (15deg BTDC. I'm using carbed cams on a SPFI setup). Coil, alternator, plug wires, battery cables, PCV, and CTS are all new. I don't have any codes. All engine hoses are new. 

My guess is it's the fuel pump, injector, regulator, or the distributor. (Cap and rotor only have about 3k miles on them).

Could also be a tuning issue. I have not fiddled with the idle control.

Any thoughts or ideas?

:]

[SuspiciousPizza]

I noticed something today while I was leaving work.

It's starting to get cold here so I let the car warm up without the heater running. As I was going to leave the first thing I did was turn the heat on. Hmmm. The idle dropped 300 rpm and started to sound like it wanted to stall.  

Perhaps I have some sort of vacuum leak and that's causing the issues. The EGR valve operates with vacuum. Maybe it's not operating properly due to vacuum loss. 

Perhaps this is causing my fuel smell? 

Some time in the next few weeks I'll run a D-check, do a fuel pressure test, and check for vacuum leaks. 

I've given the entire engine bay the smell check for fuel leaks and didn't find anything. I don't smell gas in the garage either after it's been sitting overnight. I do keep an extinguisher in the car though.

:]