wjburken
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2004 6.0 NV4500 Tahoe
- Thread starter Dantheman1540
- Start date
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Dantheman1540
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I'm still on the struggle bus when it comes to tuning this thing, It seems like no matter what I do to the VE table it still has erratic fueling issues. For example when coming to an idle it will first idle at 12.0afr then smooth out to 14.7ish then go super lean and stay lean like 16.5-17 until I touch the throttle or begin to move again in which it restarts the pattern. It reallys throws my histogram data off because despite having 6k hits in the idle cells some of those hits are crazy lean then some rich then some in the middle so what should I base the data off? it even does this with STIT active and I noticed that despite commanded being 14.7 and actual being 14.7 the ST fuel trims are showing -25%. Is that meaning they are seeing its 25% lean? Maybe its the fever or the low IQ but I'm confused.
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Dantheman1540
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Finally starting to feel better and I tried to order a new cluster for a buddies 05 2500. Put in the order with Carl and in the confirmation email he sent me he said "Also the 7k tach is not intended for competition or shift points, it’s not that accurate.". Not gonna lie that really ****** me off! I've personally noticed that it seems off up top but I kinda thought it had to do with the fat Esky needles being hard to read moving quickly and my eyes darting from gauges to road and back so quickly. Highly disappointed that this isn't described in the description of the cluster I would have just gotten a 6k cluster for $150 less without the Esky needles. To me this makes the inaccurate 7k tach more useless than a standard accurate 6k. I guess I need to do some real testing to see how much its off and what points is it off at.
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Dantheman1540
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Ok who knows about Efan conversions blowing relays? Another fan relay is down and my AC quit last Friday for no reason. It’s doing exactly what it was doing before I changed a bunch of AC setting in the tune but I haven’t touched any of that stuff since so idk wtf!
Also having weird fueling readings with my afr so I’m pulling the passenger header and welding a new bung in front of the awful V band that leaks.
On the plus side I got a shipment of titanium cups to practice welding this week I’m so pumped to try it.
Also having weird fueling readings with my afr so I’m pulling the passenger header and welding a new bung in front of the awful V band that leaks.
On the plus side I got a shipment of titanium cups to practice welding this week I’m so pumped to try it.
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Dantheman1540
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I should add that I swapped efans to the ones from my RCSB thinking maybe the driver side fan was starting to die and drawing more power. Replaced the relay and will see how long it lasts this time.
randeez
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im sure ive asked but make sure the maf is completely disabled, de-pin the connector if you have to. dont go into PE mode, disable fuel cut, reset the fuel trims after every log/tune.
-25% means the tune wants to pull that much fuel out, so youre way rich.
you almost need to just disregard start up and fluke temp swings. try and always tune the VE same outside temp, coolant temp, IATs, no AC
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Dantheman1540
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MAF is not De-pined because I haven't fully comited to SD only and I just don't feel like doing it so early in the tuning process.
Don't go into PE you mean disable it or keep throttle% under PE enable?
Fuel cut is disabled, however I feel that during cruise when on and off the gas since its manual the compression braking seems to lean out like crazy possibly throwing off data. I can avoid this by throwing it in neutral anytime I'm coasting but I need it to idle properly first.
I know -25% is crazy rich but I'm not sure its a 100% accurate reading.
Disregard startup meaning the first 5 seconds or the first minute or two?
I really really think a lot of the issues are the exhaust leak, it doesn't sound loud but with my hand up next to it I could feel a considerable amount of leaks at the V band. Should have it solved this week tho.
Do you tune looking at the O2s? if so do you build a histogram?
randeez
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You need to make sure the maf is completely failed when tuning the ve table. They blend for fueling otherwise, so if you pull fuel from ve table the maf going to say you need more. But it doesn't differentiate from which.
Disregard first couple minutes
Exhuast leaks that close to o2 sensors will screw everything up. On decel you get reversion, where is sucks air back in thru the leaks
My wide band is in a 4" pipe so it's not very "accurate" at low flow, I still use the narrow bands for anything under 3000rpm or so
Disregard first couple minutes
Exhuast leaks that close to o2 sensors will screw everything up. On decel you get reversion, where is sucks air back in thru the leaks
My wide band is in a 4" pipe so it's not very "accurate" at low flow, I still use the narrow bands for anything under 3000rpm or so
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Dantheman1540
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How exactly do you use narrow bands? I've always read that narrow band tuning is trash and for people who can't afford a wideband lol.
