0411 help

[best97obs]

I've had the 0411 pcm for awhile now. It likes to over advance the timing when it is cold. Not sure why tho. My tuner came out a couple times after the first tune job to check what was going on. he thought he fixed it but didn't. When warmed up it runs like a dream, just does it when cold. Not sure if anyone has had the same problem or not but I just wanna know if it's even possible to make it not over advance the timing when cold. It also likes to die when put into any gear(besides neutral) when it isn't warmed up. Any advice would be helpful, I will send screenshots to my tuner with any help I could get on this. Thanks in advance.

 

[L31MaxExpress]

Why do you assume it is over advanced for the operating conditions? Some of the timing added is in the Coolant Temp compensation table and some is in the Catalyst Warmup spark table. GM adds a lot of timing to the warmup on purpose. At light throttle, off-idle the engine will want all the advance until it warms up. Not uncommon to see 40+ advance at say 1,500 rpm and 120F coolant temps. The cold air/fuel mixture needs more timing to completely burn in a cold engine. My 383 wants over 30* of timing advance at idle when it is cold and as much advance as the distributor will allow off-idle when it is cold.

Sounds like the Base Running Airflow is off, that or if it has an aftermarket throttle body the IAC Step Flow table is off.

 

[best97obs]

alright thanks. It doesn't have an aftermarket throttle body, wish I could find one tho. I will have to talk to my tuner, what I've been doing is letting it idle for 5-10 minutes before I go anywhere. One day I thought it was warmed up and on my way to school it died at a red light and once I started it again it didn't have any power because it was popping and cracking like the timing was advancing. The only reason I assume that is because my tuner told me that the computer is used to over advancing the timing and the 5.7s can't over advance as much as the computer wants it to. I really wish I could find someone who tunes these 0411s to perfection for these 5.7s. My tuner is good but he said 0411 swaps are tedious and hard to mess with.

 

[BeXtreme]

My tuner is good but he said 0411 swaps are tedious and hard to mess with.

Sounds like you need a new tuner, preferably someone very familiar with tuning Gen III... there really isn't anything special about it being a swap.

 

[L31MaxExpress]

Sounds like you need a new tuner, preferably someone very familiar with tuning Gen III... there really isn't anything special about it being a swap.

Agreed, the 0411 runs the same exact L31 in a van out of the box. There is nothing tedious about getting it to run on the stock van tune. Flash the van tune into it, turn the VATs off on a pre 98 truck and it runs. Runs better than a stock L31 ran. I got mine fired up on a stock tune with a Hypertech 4.3L spark map copied into it and it ran flawlessly even with headers and a small cam. Then I drove it, datalogged it and adjusted the VE table, base running airflow and a few other things until it was happy. Tuning a L31 on a Gen III controller is the same exact procedure as tuning an actual Gen III engine, the only difference is the L31 likes a different timing advance curve.

 

[L31MaxExpress]

Biggest issue I had on mine was getting the marine manifold to behave, especially on E85. Until the pumpshot fuel is dialed in they have a lean bog until they warm up.