Other than idle, the car runs well. Fuel trims for both banks hover around-1 to -3. But for whatever reason, the car has a hard time idling whenever I shut it off, and turn it back on when it’s warmed up. I’ll have to modulate the throttle a little bit or else It will die. Also when coming to a stop sometimes the idle will bounce around from 5-900 a few times, and then it will idle properly. Other times it comes down to an idle just fine. I replaced the fuel injectors a while ago because I bought some crappy eBay ones. The issue was fixed for a while, but now it is doing it again. I also had a timing issue. I pulled the front cover and discovered I had read my adjustable timing set incorrectly. Now it is fixed. Could this somehow be related to it? Would the tune be off now that the timing is fixed?

 

LOL!! I had the exact same issues after a heads/cam mod install. My tuner was really really good at the major tuning changes but due to a time crunch, he was unable to adjust the fine-tuning issues that cause that very issue. I have EFI Live. I know how it works BUT, laying hands on that critical tuning stuff is NOT MY CUP OF TEA. I have people that are very good at that sort of stuff.
Here are a few things that I learned watching the masters work their magic.
You need to: 1. Make sure that you have no vacuum leaks and or unmetered air entering the intake! 2. Readjust the idle timing table for normal idle & Idle when the AC is ON! If you don't adjust both tables, the engine won't idle properly when you change from AC ON or AC off.
To make any changes to the C5 PCM, you need to use EFI Live, HP Tuners or some other tuning software. If you don't have tuning software, you have to pay the $$$$ to have a knowledgeable tuner do it for you. Im sure other tuning knowledgeable people will jump in and provide more or better inputs.

The LS idle is one of those things that often get overlooked or improperly adjusted. Especially the AC ON and AC OFF idle tables.

Who retuned your PCM after you recammed the engine and exactly what engine mods did you undertake? Take it back and see if they can readjust those tables. If the car timing gear timing was changed after the tune , IT MUST BE RETUNED for it to run to its fullest capability and run efficiently.

 

I have HPtuners, I went through mailordertuner online. BTr stage 3 cam and long tube headers, I also have 243 heads.

 

Give me a call,, PM SENT.
Do you know of anyone locally that can use your HP Tuners and adjust the idle tables? Some mail order tuning people will do minor changes without charging you BUT, doing those idle tables that way would be tough.

 

I will give you a call this evening. There is a local
place around here I was going to take it to.

 

Mine did a lot of what you say before I had it dyno tuned. I can pull my tune file if you want to look at the difference. It might give you an idea on what to change. They played with a lot more tables than I expected when I went in to see the differences from the previous tune.

 

yeah if you could that be great!

 

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