1 more time

[justin123]

i asked this in a eariler thread but im not sure if everyone seen it . anyone know how to make a 5.3 liter lope at idle?? ive been thinking so hard ive had a headache and just cant seem to figure out what needs to be done if anyone has any ideas please let me know im open to any suggestions thanks :confused:

[mr.prick]

Reduce your desired idle RPM.

[Baldric]

Reduce your desired idle RPM.

+1

just dont go too low. or it will give you the shits. keep stalling etc

[Stealth97]

Put in a cam rated for about 500hp-500 tq. Should lope pretty harsh.

[justin123]

thanks for the info. im trying to do it with programming only. surley theres a way to do it i just believe its very complicated and would involve alot. if im not mistaken the lope is created by a low vaccum condition caused by large cams but i figured theres a way to make a low vaccum on the engine at idle and adjust the fuel to maintain at a certain amount and open the butterfly up to allow a little extra air w/o the fuel but im not real sure if thats possible or if it is would it create a dangerous lean condition. thanks

[Stealth97]

thanks for the info. im trying to do it with programming only. surley theres a way to do it i just believe its very complicated and would involve alot. if im not mistaken the lope is created by a low vaccum condition caused by large cams but i figured theres a way to make a low vaccum on the engine at idle and adjust the fuel to maintain at a certain amount and open the butterfly up to allow a little extra air w/o the fuel but im not real sure if thats possible or if it is would it create a dangerous lean condition. thanks

Lean at idle is less destructive than lean above 3000RPM at WOT. I'm no expert but I'm theorizing you could have your vehicle very lean at idle and suffer no real ill effects unless you left it idling for a long period of time. Short idling time with a lean condition should do no harm.

Anybody else want to chime in?

Also, I think the easiest way to make it lope is to screw with the IAC. I had an IAC problem once and my truck idled real strange and lopey (not a good lope however, didn't sound fast, sounded 5 cylinder or something, LOL). I think I reset the IAC and it was better.

I'd say open the throttle butterfly to reduce vacuum. Add a bunch of fuel to make it rich, and it'll lope real good. Maybe I'm wrong but thats just what I'm thinking I would start with anyway if this is your real goal.

[justin123]

well my thoughts on that is if i open the butterfly up to reduce vaccum and add fuel... wouldnt it idle up?? b/c thats how rpm is increased more fuel and air right?? so i would think just open the butterfly up but....... how do i do that???? and what modifications to the iac would u suggest?? im not really good with the gas engines im better with diesels b/c ive messed with them longer. thanks for the help

[GMPX]

low timing will make it lope(ish), but on a stock cam it will probably just run like crap and not sound like it's got a cam.

If you try to do it via very low idle speeds the PCM will probably be fighting you trying to maintain idle. This kind of reminds me of those blow off valves that ricers fit to N/A motors to make them sound like they have a turbo :sly:

Cheers,
Ross