I think my fueling is jacked some how? Not sure, please check this out...
01-08-2006, 03:19 AM
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I think my fueling is jacked some how? Not sure, please check this out... Ok, had the wideband hooked up today.
1) At idle, I am a little rich, 13.3:1, not sure if the throttle blade should be adjusted, or stick with VE Tuning for this?
2) Next, cruise is fine, 14.7 hovering in that range +/-.2. But, when coasting downhill in second ( I have a TH350 rmvb, so I tend to engine break if you will) the AFR shoots to around 8 or 9:1, rich as ****. I always thought when decel it went lean as ****. Is my car normal with this due to the "engine braking" or do I need to tweak the DFCO or other table?
3) when coming to a stop, and idling begins, the AFR sometimes is richer than stated in #1, like 12.8:1. I am not sure, but thinking this might have to do with the VE needing to be dialed in, or simply the cam.
Cam is relatively decent size, 231/242 .637/.622 114* and using 42lb injectors. I need to recheck the min inj cycle and make sure I reduced that, I know on my buddies car it needed reducing or the inj simply couldnt accurately control the low idle fueling as well.
Any help is greatly aqppreciated.
Charlie
1) At idle, I am a little rich, 13.3:1, not sure if the throttle blade should be adjusted, or stick with VE Tuning for this?
2) Next, cruise is fine, 14.7 hovering in that range +/-.2. But, when coasting downhill in second ( I have a TH350 rmvb, so I tend to engine break if you will) the AFR shoots to around 8 or 9:1, rich as ****. I always thought when decel it went lean as ****. Is my car normal with this due to the "engine braking" or do I need to tweak the DFCO or other table?
3) when coming to a stop, and idling begins, the AFR sometimes is richer than stated in #1, like 12.8:1. I am not sure, but thinking this might have to do with the VE needing to be dialed in, or simply the cam.
Cam is relatively decent size, 231/242 .637/.622 114* and using 42lb injectors. I need to recheck the min inj cycle and make sure I reduced that, I know on my buddies car it needed reducing or the inj simply couldnt accurately control the low idle fueling as well.
Any help is greatly aqppreciated.
Charlie
01-08-2006, 04:42 AM
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Might be your o2 location, if they are too far back they might not be reading right. Once driving they might be heating up ok.
You can go into open loop fueling which you will need to do to tune ve and if your fueling is ok then you can look at the o2's as a possible point of issue.
You can go into open loop fueling which you will need to do to tune ve and if your fueling is ok then you can look at the o2's as a possible point of issue.
01-08-2006, 12:27 PM
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Maybe log your o2 voltage, perhaps they are getting old. In closed loop they should be controlling fueling at idle in a stock pcm to stoich, so check them first. Let us know if they are switching properly. If your ve is ok you could confirm the rest of the system is ok by running open loop and comparing. An overly rich mix can damage them.
01-08-2006, 12:45 PM
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The O2's are cycling fine. The PCM has been tuned via HPTuners, by myself, but I havent changed stoich setting. I am thinking the new heads and cam are messing with the idle fueling, either needing to open the TB Blade angle more/drill the hole more (I have both on this car drilled and flipped the TB Screw) or just tweak the VE table, since I havent done any VE tuning...except from the Basic Cam "how to idle" where you subtract 60%, 70%, 80% in the lower rpm region, which is probably way different from the previous cam.
01-08-2006, 02:05 PM
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What are the LTFTs saying during these events?
Are they indicating purposeful enrichment? If so I
still might be inclined to suspect mis-trimming (O2s).
Particularly the decel, they are going to be pretty
starved for both gas flow and heat. The decel also
might put you to a MAP lower than you normally
have a chance to tweak in, VE-table-wise, but the
question in my mind is why isn't it trimmed to stoich?
Are they indicating purposeful enrichment? If so I
still might be inclined to suspect mis-trimming (O2s).
Particularly the decel, they are going to be pretty
starved for both gas flow and heat. The decel also
might put you to a MAP lower than you normally
have a chance to tweak in, VE-table-wise, but the
question in my mind is why isn't it trimmed to stoich?
01-08-2006, 03:23 PM
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I didnt look at the LTFT's, since I hadnt had the LM-1 wired into the EIO yet I was only looking at the WB.
Could this be from not reducing the min. inj time, with 42lb inj? Or, from the new cam not getting enough air, TB Blade hole or screw adj?
Could this be from not reducing the min. inj time, with 42lb inj? Or, from the new cam not getting enough air, TB Blade hole or screw adj?
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03-26-2006, 11:27 AM
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Originally Posted by CAT3
Ok, had the wideband hooked up today.
1) At idle, I am a little rich, 13.3:1, not sure if the throttle blade should be adjusted, or stick with VE Tuning for this?
2) Next, cruise is fine, 14.7 hovering in that range +/-.2. But, when coasting downhill in second ( I have a TH350 rmvb, so I tend to engine break if you will) the AFR shoots to around 8 or 9:1, rich as ****. I always thought when decel it went lean as ****. Is my car normal with this due to the "engine braking" or do I need to tweak the DFCO or other table?
3) when coming to a stop, and idling begins, the AFR sometimes is richer than stated in #1, like 12.8:1. I am not sure, but thinking this might have to do with the VE needing to be dialed in, or simply the cam.
1) At idle, I am a little rich, 13.3:1, not sure if the throttle blade should be adjusted, or stick with VE Tuning for this?
2) Next, cruise is fine, 14.7 hovering in that range +/-.2. But, when coasting downhill in second ( I have a TH350 rmvb, so I tend to engine break if you will) the AFR shoots to around 8 or 9:1, rich as ****. I always thought when decel it went lean as ****. Is my car normal with this due to the "engine braking" or do I need to tweak the DFCO or other table?
3) when coming to a stop, and idling begins, the AFR sometimes is richer than stated in #1, like 12.8:1. I am not sure, but thinking this might have to do with the VE needing to be dialed in, or simply the cam.