idle speed 4.8L
 

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[blockquote]I was wondering if anyone might know a way to turn up the idle speed just a bit. I notice when i am coasting or going real slow, the RPM's drop to about 600 - 700 RPM's and notice when i step on the gas, theres hardly any momentum gain, its what i call a mushy throttle,and then when the RPM's catch up to the clutch engagement speed, thats when it clunks in the rearend. The dealership has checked everything and found nothing unusual. I did notice the tranny fluid was down about 3/4 of a quart tho, and that could be due to a slow leak around the driveshaft seal that goes into the tranny. I'm gonna check the rearend fluid level this weekend, just to make sure its up to level, and a friend of mine told me to drain and put in newand adda bottle of Lucas 90W oil as well.Could the oil be that brokedown to cause the rearend to clunk? I haven't had time to check to see if adding the 3/4 of a quart to the tranny helped. Any suggestions? The truck has 64,000 miles on it.






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RE: idle speed 4.8L
 

It can not be idled up...but there IS a program to correct a very low idle on those...it is a pcm flash+ cleaning the throttle bore

RE: idle speed 4.8L
 

Hey Argon, Have any idea what the truck is sposed to idle at? Seems to me, if something was wrong, a code would show, but i just have to inquire. Right now, it idlesbetween 700 and800 RPM's. It seems like the void or non responsive throttle response is whats causing it to make the clunking noise. I just have a hard time believing its the nature of the beast, as my wifes Avalanche with the 5.3L has excellent throttle response, and theres NO hesitation at all............ Can 2 vehicles/engines be that much different? Her Av is an '02.


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RE: idle speed 4.8L
 

650 is probably its target...as for throttle response...maybe the fuel filter?..or dirty throttle bore

RE: idle speed 4.8L
 

maby even the air filter?

RE: idle speed 4.8L
 

Hey all, update: I bought and installed a new fuel filter, as mine was on inside of frame rail on drivers side. Knock on wood.......... It definately seemed to help with throttle response, by what i have seen so far. As far as the air filter, i have a K&N FIPK. Hey Argon, whats it cost or whats involved in cleaning the throttle bore, and would a TBS help out at all? What does the TBS do performance wise and will i be able to use a TBSwith my K&N FIPK? Thanx all, Jim


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RE: idle speed 4.8L
 

The TBS will give you faster throttle response, milage increase, and power increase. As far as cleaning the throttle body, just some carb cleaner and a clean rag should do it.

RE: idle speed 4.8L
 

you should have seen my throttle body when i switvched engines, almost made me sick, but yeah i cleaned it all up with a can of carb cleaner and a rag, like smoke said and it was good as new

RE: idle speed 4.8L
 

To clean the bore..get some throttle cleanerv (this may be hard to find)...it has a lubricity to it....carb spray will dry out your butterfly hinges and remove the "coating" thats on the throttle bore.

Just use some common sense and don't spray too much in...I have heard of guys busting a piston from spraying half a can inside

RE: idle speed 4.8L
 

If you have the time to do so....take it off and clean it. I sprayed it before and it helped but there is usually quite a bit of crap on the inside where it can't be reached.