Tuning or other issues after Heads Install...need help
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From: Sierra Vista, AZ
Tuning or other issues after Heads Install...need help Ok, my friends installed a set of PP5.3L Stage 2 heads (fresh out of machine shop after being checked etc..) in my was stock headed TSP 231/237 cam only DD. This is on a 2000 Z28, 853 castings (believe these are the worst example of flwoing heads too!).
When Cold, have to hold the throttle just a tad til its warm or it stalls, never did that when prior to heads. Once warm its ok.
Now the LTFTs are pegged at +25 at idle, STFTs are pegged at +50.
At PT/cruise the LTFTs come down to about +14 hold somewhat steady, not bouncing all over the place, havent got it WOT yet. This would suggest it is running lean as **** idle, and not so great, still lean, at PT correct?
Now, is this normal after installing a set of S2 Heads or does it sounds more like either a vacuum leak/bad O2s?
The O2s do switch, although notably slower than a car with known to be good ones, so quite suspect! Mv are around 400 and drop to 90 or so and switch rather slow, could be they are switching "normal" just ahs a bad tune or a vacuum leak???
I am thinking if it was more of a vacuum leak, it wouldnt come down at PT/Cruise it would still bounce around and stay lean as ****, but then again it may not leak as bad under PT?? The intake tract will be propaned for leaks in the next fews days to confirm or deny vacuum leak.
Send me your thoughts please.
TIA
Charlie
When Cold, have to hold the throttle just a tad til its warm or it stalls, never did that when prior to heads. Once warm its ok.
Now the LTFTs are pegged at +25 at idle, STFTs are pegged at +50.
At PT/cruise the LTFTs come down to about +14 hold somewhat steady, not bouncing all over the place, havent got it WOT yet. This would suggest it is running lean as **** idle, and not so great, still lean, at PT correct?
Now, is this normal after installing a set of S2 Heads or does it sounds more like either a vacuum leak/bad O2s?
The O2s do switch, although notably slower than a car with known to be good ones, so quite suspect! Mv are around 400 and drop to 90 or so and switch rather slow, could be they are switching "normal" just ahs a bad tune or a vacuum leak???
I am thinking if it was more of a vacuum leak, it wouldnt come down at PT/Cruise it would still bounce around and stay lean as ****, but then again it may not leak as bad under PT?? The intake tract will be propaned for leaks in the next fews days to confirm or deny vacuum leak.
Send me your thoughts please.
TIA
Charlie
Last edited by CAT3; Dec 24, 2004 at 01:43 AM.
