erratic throttle questions
06-28-2011, 10:59 PM
#1
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erratic throttle questions While driving around in my 03 chevy silverado LM7 I noticed that after my rpms came down to about 1500 rpms under load conditions my rpms started jumping up to 1700 and back to 1500 until throttle was depressed enought to surpass the erratic changes. Im pretty pissed about this considering the air/fuel is 100% exact i think its supposed to be like 13 5 or something to that effect i cant remember. The engine has been tuned with hp tuner and the fuel filter is new. The only other thing i can think of is the fuel pump. It is cammed with a crowder cam stage 3 and i know that cam is asking for much more air and fuel with the stock intake and injectors but if the air to fuel is that exact it pretty much dismisses that. So im like a gorilla scratching my head right now. Any ides would be great.
06-29-2011, 06:26 AM
#2
Might want to first clean the java motor on the side of the tb, then if that doesn't fix it I'd look at your high/low octane spark tables, throttle cracker, and throttle follower in hptuners.
What are the specs on that can, what is the operating rpm range?
Hope this gets you alittle closer to where you want to be!
What are the specs on that can, what is the operating rpm range?
Hope this gets you alittle closer to where you want to be!
07-01-2011, 02:05 PM
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I got to the bottom of it. Thank you for the help. It was the Ve tables. The shop I had tune it, didnt do any driveability trends on it so I just need the tables tweaked. I noticed when it was being dynoed for some reason at wide open throttle instead of climbing up it shot straight the hell down. Aftertroubleshooting we determined some extra grounds were needed? Any you guys ever heard of this happening? I never have personally but as soon as we added those extra grounds that engine woke the hell up. it was one of those weird things. I reviewed the factory service manuals to make sure the original grounds were in the right place and sure enough everything checked out. So between that and the VE tables I am sure thats were the problem lies.
