Anyone have that? i know normally a cold engine is going to rev high and then idle until warm but i noticed my 5.3 revs alittle too high before settling and does it even when already warmed up? im gonna check the IAC first but i wanted to see if maybe some others had this issue...

 

Hook a scanner up and monitor the TPS value and IAC steps

 

Whats hi? Mine revs to about 1800 for 2 seconds them idles its way to about 1000 after 10 seconds. Stays that way till warm then holds an 850 idle.

 

Watch your volume on this... But here's a vid showing my tach during a colder start up. Its open headers...but its how it acts all the time.

Well....this is before my last tune. My hot idle is set a little lower now. In the vid, it was set around 900 I believe because of the alum flywheel.

http://www.youtube.com/watch?v=hd3Pr...eature=related

You can see it flares for a second or two, then settles down. It does this even when its colder outside. Might stay a LITTLE higher for a bit...but no where above 1000rpm. Might idle at like 950 for a minute before settling to 900.

You could check vac lines, check for leaky injectors, and also check what Pocket said. Is this a stock tune? Or has someone tweaked it?

J.

 

Well it has a tune by Spareecm, stock ls1 tune with 26# injectors. I watched it some more last night and it did get a little better after it was warmed up and driven but i think i should get some fresh sensors, the ones i have on the TB have about 50K on them. It hits almost 2K on the tach. My speedo isnt working either for some reason. Little steps i suppose. thanks for the responses.

 

I wouldnt jump to throwing a new TPS or IAC in there.....If the MAF sensor is doing anything dumb it could cause a spike in RPM but it could also be in the tune. I would look into the tune first before changing anything. Well thats after checking for vac leaks.

 

Did you bypass the buffer box since your bird was a TBI?

 

I was going to mention whether or not you are sure your TACH is set up properly. Or is it obviously revving high (using your ears).

I agree on not just tossing sensors at it. 50k isnt an indication that a sensor is bad. I have sensors on my Jetta that are 140k old with no issues. Not saying its not a sensor...but I would do some more checkin.

Ide suspect the tune at this point especially since it had some fuel tinkering done via a mail in operation.

Are you planning to have it tuned any time soon?

J.

 

no i didnt

 

ghetto i watched your Vid, looks like mine is only a few hundred RPM's above that so maybe its not as abnormal as i suspected it. im going to mess with it more friday/sat/sun since its been raining like crazy here. thanks for all input.

 

Find the buffer box and connect pins C and F. A short length of wire bent to a U with spade terminals will suffice

http://www.austinthirdgen.org/mkport...SS_V8_vinE.jpg

Jumping a few hundred RPM for a few seconds is normal, atleast for all of my LSx stuff, even the stock truck does it. It never breaks 2,000rpms though

 

thanks jon, i dont know what the hell i would do without you. lol