Z71 bog.
07-31-2012, 06:44 PM
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Z71 bog. Hello. I need help with my silverado. It has an lq4/lq9 shortblock, ls3 heads, l92 truck intake manifold, professional products throttle body, and a Voo-Doo cam. Cam specs are 212/218 .531"/.531 113lsa.
Here's the issue. I can be cruising along and need to give it throttle to accelerate with part throttle it seems to bog momentarily the catches itself and does fine. If I start from a dead stop and just accelerate normal its fine. If I punch it from a dead stop it pulls like it should. If I try to do a burn out with it; it won't. Acts like something's holding it back. It's got a new gm maf and map. Fuel pump was replaced about 2 1/2 years ago from gm. Is tuned by a very good tuner in the local area. Any idea's? Thanks. Ben
Here's the issue. I can be cruising along and need to give it throttle to accelerate with part throttle it seems to bog momentarily the catches itself and does fine. If I start from a dead stop and just accelerate normal its fine. If I punch it from a dead stop it pulls like it should. If I try to do a burn out with it; it won't. Acts like something's holding it back. It's got a new gm maf and map. Fuel pump was replaced about 2 1/2 years ago from gm. Is tuned by a very good tuner in the local area. Any idea's? Thanks. Ben
08-01-2012, 06:26 PM
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I'd begin by looking for knock retard and then at the burst
knock settings, which are too sensitive on early trucks.
Log all the advance and retard subcomponent PIDs you
can. If there is a retard action, see if it's initiated
by a "lean hole" in the O2 sensor readings, that would
tell you your air mass value from the speed density side
is too low ("lean is mean", nice guess, but wrong).
knock settings, which are too sensitive on early trucks.
Log all the advance and retard subcomponent PIDs you
can. If there is a retard action, see if it's initiated
by a "lean hole" in the O2 sensor readings, that would
tell you your air mass value from the speed density side
is too low ("lean is mean", nice guess, but wrong).
08-08-2012, 05:49 AM
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Take it back to the tuner and make him get it right... If he really is a "very good tuner", he will... If it runs better without the MAF sensor, the tune is probably not right... It is impossible for us to diagnose something like that over the internet without a tune and logs to look at - could be any number of things...
