Lumpy idle, rough running, and gas smell

[Hoffbrohaus]

Decided to start attacking this problem again. I need some more help troubleshooting since I'm tired of throwing parts at it.

All the symptoms I can think of:
Long start/crank now and then - no rhyme or reason, could be cold, hot, sat for a short time or long time
Idle is lumpy like a big cam
Smells rich but I think it's gas from the engine bay since it's apparent when the vents are on
HP is low and on a dyno and the sniffer says it's lean
Occasional knocking or pinging with 91 octane or maybe a misfire?
Fuel pressure is right but doesn't always hold after car is turned off

Things replaced:
Fuel filter, Fuel pressure regulator, Fuel rail
injector harness, injectors & o-rings
AFM
Temp sensor
Plugs (gapped fine), Wires, and Coil
Adjusted valve lash to within specs..multiple times
New o2 sensor
Smoke test = no vacuum leaks

Things checked and ok per bentley:
ECU resistances
Crank Position Sensor
Fuel Pump
C101 thing or whatever it's called

Possibilities?
Dizzy - Checked for cracks or trails and saw nothing
Charcoal canister - Thought maybe the gas smell but doubt this would lead to rough running
Fuel pump check valve - for the loss of fuel pressure after turning off, but shouldn't effect motor performance
Fuel lines - didn't see any cracks or leaks but maybe the only show up under pressure in certain circumstances?
ICV - gave it voltage and it closed per bentley but doesn't really reopen, it buzzes with key on
Anything else?

[Tinkerer007]

I'm no diagnostic genius. But...

I was replacing the injectors on my car last week with M50 ones. And while removing the electrical connectors to the injectors I noticed the #3 and #4 wires were swapped.

The car now runs smoother. Revs free-er. Is quieter. With the last smog test, I had to replace the cat as it was empty. I think there was unburned fuel getting into the exhaust, and getting ingnited there. The car was running rough, and the exhaust smelled rich...

[Hoffbrohaus]

I'm no diagnostic genius. But...

I was replacing the injectors on my car last week with M50 ones. And while removing the electrical connectors to the injectors I noticed the #3 and #4 wires were swapped.

The car now runs smoother. Revs free-er. Is quieter. With the last smog test, I had to replace the cat as it was empty. I think there was unburned fuel getting into the exhaust, and getting ingnited there. The car was running rough, and the exhaust smelled rich...

Interesante! Never thought the Cat could affect performance. I don't have a cat at all. PO took it out and welded a straight pipe.

I'll check the harness but I completely replaced it so doubt it's wrong but I could have screwed it up.

[ahlem]

Possible vacuum leaks at the Throttle body. How did you do the smoke test? You said you had injectors replaced. Used, Used but tested or new? Cap and rotor contact points could be rough. O-rings at the dipstick can be checked by pulling the dipstick while it's idling. Breather hose from your valve cover in good shape and attached with hose clamps? You can do a low pressure 5psi test into the crank case to see if you have some other air leak somewhere.

[Hoffbrohaus]

Possible vacuum leaks at the Throttle body. How did you do the smoke test?

Just the cigar smoke test.

You said you had injectors replaced. Used, Used but tested or new?

Used but refurbished and tested. Installed by me.

O-rings at the dipstick can be checked by pulling the dipstick while it's idling. Breather hose from your valve cover in good shape and attached with hose clamps? You can do a low pressure 5psi test into the crank case to see if you have some other air leak somewhere.

Dipstick pulled causes car to stall so that's ok right? Breather looks ok and is clamped on tight but there is a little oil on the valve cover by it.

One other thing and I may just be hearing things but sometimes when I shift I swear I hear a puff of air or something. Like a tiny blow off valve. But it could be nothing related and just a tranny noise.

[ahlem]

Maybe time for a new valve cover gasket and make the $20 smoke tester as seen on youtube. I'm guessing you have some small vacuum leaks in several places and a good cigar is just a good cigar. Could also be your oil filler cap.