I DO!! I don't know if this is a symptom of the larger than stock cam or if it can be tuned out. I have asked a few times over on the hptuners forum but it's like pulling teeth to get anyone to reply.

With the mods in my sig, should I have such a hard time starting my truck in hot weather? I've used the search and can't find any good advice on how to combat this in the tune.. Usually it takes several cranks of the key to get it to fire. The two logs below are pretty good starts but thrity minutes before I made the logs, it acted like it wasn't even going to start at the grocery store. Sometimes it will fire one or two cylinders and not start. Any ideas?

 

Who tuned your truck?

BTW, I was much in your predicament regarding driveability when I had my yank pt3600. It was a very tight stall, but I got sick of driving it stop and go, and towing was not fun either. So I just threw in the stock 4l80 converter with the mid 220s cam. Driveability is identical to stock, never stalls surges wont start etc. I just can't imagine a 231/239 should be giving you all these problems in a 6.7L.

 

I had WOT tuning done by the Chevy dealership here and I've done the rest. Im definitely not an expert but still trying to learn

 

I don't use HPT, do you have an idea what is happening? Is it too rich? If so, try holding the throttle to the floor and start it. Like a carb engine. The computer has a feature in the tune to cut fuel when wot and cranking.

 

I did try that earlier today without any luck. I will add some fuel to the cranking VE and see if there is any improvement.

 

Did you actually properly tune the VE?

 

Haha of course the ve is tuned.

 

One thing I would suggest is to check the fuel pressure. Mainly for a leaky injector. See if the pressure bleeds down when you turn the key off. If it hold steady, that is one area you know is OK before you start changing the tune. If an injector were leaking, I could see it causing this problem. When it has sat long enough to cool down, the fuel could have evaporated. Just something that popped into my head.

 

As suggested already I would definitely check anything fuel related not in the tune first. Fuel pump, regulator, fuel filter? Make sure you've got good pressure at all times at the rail.


Do you have all of your idle airflow tuned correctly?

Can't see your tune from my phone, you running open loop or closed loop? Speed density or MAF? What injectors, injector data right in the tune?

 

Wow, I just saw your reply. I'm still having trouble with this.

Idle airflow is correct. Trims hoover around zero like they should. I'm running closed loop with a MAF. I'm running stock ls3 injectors with data that should be good. I got it off hp tuners forum.

After the truck is started, it doesn't seem rich or lean. ?? I'm confused.