Help with cold start, it's piggie rich. Gen 2

[ChrisChow]

My stats are:

Gen 2
Extender extreme
72 lb siemans injectors
ECM modded for Low Z
Iron heads
forged stock block assembly
212 212 roller cam
Walbro single in-tank
stock fuel pressure regulator...it believe it's 43 psi with the vacuum hose off.
LC1 innovate wide band (not currently used by MafT)
Stock O2 sensor (seems to be in good working order)
Every wire was meticulously soldered in by me

So it runs really fat on cold start even after dropping the "low load" by 18% at 1200 rpms. Coincidentally, dropping the "low load" by 18% reduces the idle in neutral AFR to 13 or so.

As soon as my LC-1 wide band gauge kicks in during a cold start event, I'm reading about 9.8 to 10.1 A/F. Once the temperature gets to about 120 degrees F, the rich condition is gone. Car runs great, WOT 15 psi on Cali Craptane: awesome!
Warm startup is good.
Car does NOT stall.

So, if I reduce "low load" at 1200 rpms by a new total of 30% is this going to help my cold start issues?

Is there a cold start fuel curve I can manipulate? Or do I need another chip?

 

[Eric Stage I]

The BLM that was "learned" during normal running, is also used during cold start. So if your BLM's are out of whack when warm, you might also have a cold start issue. I would get the car fully warm and see what your BLM's look like. Try to tune the "low load" area so that your BLM is close to 128, then see how cold start acts.

Eric

 

[ChrisChow]

This happened when I first started the car. There were no BLMs to go off of in the first place.

So I assume it will get better with time.

I guess it's time to buy a scan tool.
I'm new to the stock computer stuff.

The BLM that was "learned" during normal running, is also used during cold start. So if your BLM's are out of whack when warm, you might also have a cold start issue. I would get the car fully warm and see what your BLM's look like. Try to tune the "low load" area so that your BLM is close to 128, then see how cold start acts.

Eric

 

[grape of wrath]

I have the same problem with my car although it's a 3.4 turbo camaro. I installed a toggle switch,resistor and some wires. The wiring is spliced into the engine coolant temp sensor. When the switch is on the ecm sees engine temp at 150*. What I do is start the car in the off position or the car will not start, right after it fires up I flip the switch on. The ecm sees 150* and leans the mixture out. Once the car is up to temp I turn it back off. I only use this during very cold weather.

 

[ChrisChow]

I have the same problem with my car although it's a 3.4 turbo camaro. I installed a toggle switch,resistor and some wires. The wiring is spliced into the engine coolant temp sensor. When the switch is on the ecm sees engine temp at 150*. What I do is start the car in the off position or the car will not start, right after it fires up I flip the switch on. The ecm sees 150* and leans the mixture out. Once the car is up to temp I turn it back off. I only use this during very cold weather.

Hmm, interesting fix. It sure beats the very real possibility of washing down my cylinder rings with too much fuel.