Engine: B20V 99 B16 HEAD
Since I'm running the Skunk2 Billet Throttle Body, it eliminates fast idle.
So anyways when I start my car in the cold morning, it jumps to 700-900 rpm on cold start (remember no fast idle skunk2 billet tb).
-RPM stays steadily for a good 1-2min once it starts up.
-Then it starts to idle up and down from 400-900rpm.
-It idle roughly and it dies.
-When it dies, I start it back up does same thing until engine actually warms up.
-But if I just drive while engine is cold, engine runs very funny as if timing wasn't correct and it will just lag for a good 1-2 second, and when the lag goes away, it picks right back up being strong again.
-Timing belt and valve adjusted correctly TDC.
As it is completely warmed up, runs like a normal engine, no dying crap.
At first I thought it was maybe a faulty:
1. ECU- Which I tried another ECU and same thing still.
2. Distributor- Tried another, same
3. Spark Plugs- Replaced, same
4. ECT Sensor (Engine Coolant Temp)- Switch all 3, Same
*NO CEL*


Any idea where I should check next? I really need help, I've been stuck for a good 2 months with this issue.

 

I'm no expert on custom setups but I would think if you're running without an fitv you should be using a chipped ecu. The stock ecu is expecting it to be idling higher on a cold startup until it detects the coolant is warm. It's going to run rich on a cold startup however you're not giving it enough air(via fitv operation).

 

I also forgot to mention i'm on base map, neptune

 

well i took out the skunk2 billet tb and use the stock regular 1 and still did the same thing. also thought it was maybe TPS, but calibration was reading correctly at WOT and close.

 

And I just bought a Aem Uego Wide Band. I wanna see where i'm at on cold start...
Do you know what # it should be on a cold start on the wide band?

 

bump

 

Coolant level ok?

 

Fast idle is pretty important in a cold climate, or at least on a cold day. Not having it will bear consequence to your cold performance.

What do your compression numbers reveal, if all else is perfectly serviceable.

I would assume you have checked for an air leak, doesn't seem likely given the good warm performance.

O2 sensors do not work very well when cold, and most computers will ignore them completely (with the exception of the heater circuit bias) until the engine has warmed up at least, partially.

 

DCFIVER- Yes, Coolant level good.
slowcivic2k- my compression is around 230psi all around. o2 sensor is disable. and i just installed my wide band. cold start i remember it was around high 14s....and when it's going to die, my AFR starts going toward the Lean area (high 16s and mid 17s on AFR)

 

I'm thinking not enough Fuel? maybe that could be the problem?

 

Yes sounds like lack of fuel to me too