What's the trick to cold starting?

[Swagon_wagon]

Once my car is at temp it well run almost like it did with stock ecu

Now the is so touchy the lightest touch of the clutch or gas pedal will kill it. I don't get it. Its like it has no power while cold.

I'm at a loss. Iv been messing with it till suddenly my controllor wont connect. I'm working on that still. But id like to get an idea as to why my car is like this.

Also when going down the road or really any time, if you stomp the gas the car jerks violently like it has just lost all power for a split secound and then it pulls.

[Matt Cramer]

The first factor is having the fuel dialed in correctly when it's warmed up. With the exception of cranking pulse width, all other values depend on this. Required Fuel also needs to be set correctly if using MS2/Extra or MS3.

Then, let's take a look at the cold start sequence. I'll highlight all the terms that may be adjusted in bold.

1. Cranking: MS will be in this phase when RPM goes from zero to a point below Cranking RPM. The IAC valve moves to its cranking position. Fuel is injected according to the cranking pulse width value.

2. Afterstart: The MS transitions to this when RPM rises above Cranking RPM. Fuel is applied from the main VE table, initially multiplied by Warmup Enrichment and Afterstart Enrichment.. Afterstart enrichment will start tapering off. The IAC valve will move to its warmup position, often slowed by a parameter like Crank to Run Taper Time.

3. Warmup: Once the afterstart enrichment time is finished, the MS will run on the VE table multiplied by Warmup Enrichment. The warmup enrichment is never "turned off" so you will want this to end at 100% warmup enrichment (0% shuts off fuel entirely).

[Swagon_wagon]

This is exactly what I have been doing. 100percent warm up enrich after 170 degrees

Lowest temp I have tuned it for Atm is 70 has that's as cold as it has been while tuning in the morning.

I don't have a idle air valve. This may be my entire problem. It idles around 750 all the time. Maybe I should jack that to 1000 so when I first touch the gas it ain't a big shock to it.

[Swagon_wagon]

Any input from people with just the Tb cracked open

[BCM]

Try raising the idle a little - maybe 900 to start? What AFR's are you running when cold? This tapers to what > 170 degrees? Also, are you running any cold advance?

I have a car with no Idle valve, big independent throttle bodies, fairly lumpy cams. I probably run richer than most (mid to high 13's once fully warmed up at idle) and a 1000-1100 idle as it doesn't like to drop down lower than that and runs poorly if I go leaner. (But, my car is a track car, not a street driver) - I still have issues if I don't give it enough gas when trying to drive it before it starts to warm up...

Your second problem - stomping the gas when warmed up, sounds like an Acceleration Enrichment issue. Do you have datalogs to show RPM, TPS, TPSDOT, MAP, MAPDOT, AFR when you stomp the throttle and cause that stumble?

[Swagon_wagon]

Not yet as I cant get my computer to connect anymore. Ms is on hold for now while
I swap in a new transmission

Yea I got 14.7 plus at idle. I think about 17-22 degrees at idle. And the idle is at 750

[wes kiser]

How much timing are you commanding in the idle region compared to "ideal" idle timing?

In general, it yields much better results to idle the engine with a solid 10 degrees less timing than "ideal" at idle. This will force you to add additional idle aiflow (either idle valve or butterfly).

You can then add timing when speed drops below your desired idle speed (which will force a recovery, add timing using warmup advance (again will make engine happier), and subtract timing when idle speed increases above you desired setpoint.

That being said, to me it sounds as if you have way to more warmup fuel or accel enrichment. The things I mentioned will yield a more stable/easy to tune idle, but are not your primary issue.

Logs/MSQ?