Getting ACCURATE A/F's & TIMING ?????
Posted: January 24th, 2011, 11:26 am
Hey all,
Well, I'm at a few hundred miles and the stroker is still not running correctly. I did finally find a tuner/tech who REALLY understands the process though. He has a suspicion after listening to it run and my explanation of how it has been tuned, (the UniChip) that it's WAY off tune. So, here's what I'm wondering
#1-On an OBD1 vehicle, is it possible to get an ACCURATE reading from a tail-pipe probe sniffer? I now clearly understand that the A/F's are being read AFTER the CatCon has had the opportunity to alter the mix.
#2-Is using a tail-pipe probe ACCURATE anyway if you are getting the reading goin' down the road with O2 being sucked up the opening(turbulence) for 12" or more?
#3-Does an OBD1 vehicle REQUIRE a PRE-CAT bung/sensor AND a WIDEBAND to get TRUE A/F's?
Interestingly, the tuner I found USED to sell UniChip, but gave them up many years ago. He didn't speak poorly of them, but he did say that's the wrong way to get A/F's for correct tuning. I've had UniChip adjust the A/F's and timing twice and they used the tail-pipe probe both times. Should I be requesting some sort of a refund? Oh, and the tuner I've found wants to check the compression, get a solid baseline for the new mechanicals, and then drill a hole and weld on a sensor bung. Then he'll use a wideband to see where it's REALLY at and also some type of a digital scope with a BRAZILLION bits-O-stuff sampling rate. Does this sound like the correct approach?
Thanks,
T~
Well, I'm at a few hundred miles and the stroker is still not running correctly. I did finally find a tuner/tech who REALLY understands the process though. He has a suspicion after listening to it run and my explanation of how it has been tuned, (the UniChip) that it's WAY off tune. So, here's what I'm wondering
#1-On an OBD1 vehicle, is it possible to get an ACCURATE reading from a tail-pipe probe sniffer? I now clearly understand that the A/F's are being read AFTER the CatCon has had the opportunity to alter the mix.
#2-Is using a tail-pipe probe ACCURATE anyway if you are getting the reading goin' down the road with O2 being sucked up the opening(turbulence) for 12" or more?
#3-Does an OBD1 vehicle REQUIRE a PRE-CAT bung/sensor AND a WIDEBAND to get TRUE A/F's?
Interestingly, the tuner I found USED to sell UniChip, but gave them up many years ago. He didn't speak poorly of them, but he did say that's the wrong way to get A/F's for correct tuning. I've had UniChip adjust the A/F's and timing twice and they used the tail-pipe probe both times. Should I be requesting some sort of a refund? Oh, and the tuner I've found wants to check the compression, get a solid baseline for the new mechanicals, and then drill a hole and weld on a sensor bung. Then he'll use a wideband to see where it's REALLY at and also some type of a digital scope with a BRAZILLION bits-O-stuff sampling rate. Does this sound like the correct approach?
Thanks,
T~