I had the 01 denali in for the mods
vig.2800 converter

and the comp cam

here is the problem

the truck will not idle!!!!!! it feels stong in the mid range but not so much up top

i didnt think id need a ls1 edit tune for a 212-218 high lift on a 114 lobe

what do you guys think???


thanks

brent

 

Sounds to me like you need some tuning. Gotta increase idle speed for one. After the cam, the truck will surge and try to idle. Have you drilled the hole in the TB yet? Sometimes that will solve the surging idle problems after a cam install. You might need a few other things tinkered with.

 

Also, without a tune you can't take advantage of the stronger pulling cam (shift points too low) That's where some of your top-end has gone.

Jay

 

I have the same cam and the nelson's tune; even with the tune, the truck didn't idle, the only way to fix it was pressing the brake and the throttle at 600-650 rpm for a long time until the computer fix it, you have to do this in every gear until the pcm fix it's self all the way.
Now, I don't know if this would work without the tune, as I stated before, I already got the tune with the cam install.
And like 99Silver5.3 and JayStew wrote, tunning is a most, you need to raise the shift points, raise 50rpm of idle and advance some timing.
You may want to try the break-throttle thing to see if it works, and if it does, you'll have a choppy idle until you get the tune.

This takes a while, my truck was a PITA but at the the end it was worth it, once the PCM learns you'll have no problems, cam works great, pulls hard from 2500 rpm and up.

Hope this helps.

 

Are you having problems with it surging and going dead when turning real sharp from a stop? I did and had the throttle body butterfly opened a little bit (not too much or it will throw a TPS code) and it never had any more problems. But, after the tune, it was so much better all over the rpms. Try opening the blade a little bit before drilling a hole. At least thats what I was told by several people...

 

Gilberto, at what rpm's are you shifting with your new 212/218 high lift cam?

 

I would use the idle screw on the throttle body instead of drilling the hole larger. I do not remember the size but it is a torx. Give the screw a couple of turns and it should help out alot.
Other than a tune you will just have to let the computer "learn".

 

I have a much larger cam and mine idles and starts like stock. All I did was raise my idle to 850rpm, turn the throttlebody set screw open a tad bit (didn't want to drill my TB, been there done that) and changed my Idle Air values with tuning and I have zero issues. Every once in awhile I feel it stumble on a hot start but I pretend I didn't feel it and drive normal and it's gone.

The Torx screw should be a T15.

 

What's up File?
6250 rpm first - second
6100 rpm second - third
and 5xxx something (don't really remember this one right now ) third - fourth

 

You say it doesnt feel strong up top? What RPM does it start to feel like it drops off? Have you changed your fuel filter lately? Plugs etc? Also have you monitored it to make sure your fuel system is keeping up? Some people had issues in F-bods and Vettes with crappy pumps and they couldnt keep up the flow.