Txblue

iTrader: (1)

Mods are in my sig... Had a mail order tune done by a sponsor and have no complaints at all. This is my first go around with a cam and custom tune... My question is when I first crank my truck up when it's in open loop it seems like it has more *** and throttle response than after it warms up. Yes I know it's not good to do full throttle runs when it's cold and I haven't done that just at part throttle it seems more responsive... I'm not complaining about the tune at all they did a great job no drivability issues at all just was wondering about this..

subeone

The reason behind this could be associated with your airflow tables and spark tables. You could be leaning out when in closed loop as if the the open loop fueling tables are stock then it should run richer and effectively take care of ur lean tip in problem. Another reason why rhe truck is snappier is because there are several spark tables that actually add timing on top of ur base spark tables and results in a better reaponse, the truck feels lighter. If you have hptuners post your file I can try to help you out

Txblue

iTrader: (1)

I don't have any tuning software. Just got a mail order one... Guess I need a live tune? I don't want anyone to get the wrong idea... I'm very happy with my tune... I understand only so much can be done with a mail order tune... I was just wondering what the difference I feel can be caused from. Thanks for the reply. I have never tuned anything but I'm very mechanically inclined and learn fast... How hard is it to learn to tune these trucks? Should I get hp tuners and start learning? We are starting to do a lot if ls swaps into older muscle cars at work... I'd like to get to learn the tuning side so we don't have to outsource that side of it.

subeone

i just started tuning GM 5 months ago and have 2 800 turbo trucks under my belt and a 560 whp supercharged truck, countless of fbo trucks and f bodys. So if I can do it you can to. Dedicate a week to read all day over tuning with hptuners (there are a lot of how to tune threads) and you will be up and tuning. it might take u a tad longer since previous to gm I was tuning foreign engines, so i had a rough idea of what to do.

Either way, my assumption with your file is that you need more timing/fuel.

BLK02WS6

iTrader: (2)

Yes, a mail order tune can only be so good - no substitute for a live tune with a wideband. There are fuel and spark differences from cold open loop to hot closed loop, so it is anyone's guess which is off. One thing you need to be sure of is that you don't have any exhaust leaks - that can cause un-needed fuel to be added when you go into closed loop, which can cause an overly rich condition during part-throttle...

Learning to tune is hard for some, not so hard for others... I think the best is if you have someone experienced nearby you that can give you some pointers - but some people do well learning from online or books...

Txblue

iTrader: (1)

Sounds right about needing more fuel/timing... I'm sure it was set up as a safe tune... What all do I need to get set up tuning? I've looked into it and there is JUST the software then they offer sensors n such...

Txblue

iTrader: (1)

Speaking of exhaust leaks... I did have trouble getting my off road y pipe to seal but i think its good now... But I know I don't have any leaks where the headers bolt to the heads and the o2 sensor is at the collector before the y pipe so a leak in the y pipe shouldn't affect that right?

Txblue

iTrader: (1)

Even when the truck is warm it runs very strong I just noticed some differences between cold and warm

BLK02WS6

iTrader: (2)

You will need a wideband - I prefer a serial wideband because with EFILive, a serial connection eliminates any grounding issues that you see with an analog wideband connection. That is one reason I prefer EFILive to HPtuners (HPtuners doesn't have a serial input). There are other reasons as well, but most of them come down to preference, not capability.

BLK02WS6

iTrader: (2)

A leak where the y pipe connects to the header will cause a problem - yes, it is downstream of the sensor, but reversion at low rpm (cruise and idle) will pull the air back into the exhaust and skew the readings. This mainly applies to long tube headers when the sensor is near the y pipe connection...