I had been driving with the mods in my sig on the stock tune for almost 2 months and even without it tuned I was getting about 14 mpg in city and 20-22 on the highway.
Now, I have pretty much only messed with my idle tuning and a few other small things tuning wise. but I'm getting about 12 mpg (1/2 hwy 1/2 city) now! Any ideas on what could be wrong or what I need to check?! Thanks
Tyler
1999 Black Z28 - TR 224/224 114 LSA, Comp 918's, TR pushrods, LS6 oil pump, LS2 timing chain, Pacesetter LT's, TSP True duals, Spiral flow mufflers, Taylor 8mm wires, SLP lid, !egr, !air, !cats, chrome Z06's, HPTuners
Make sure you didn't leave DFCO turned off. That will help mileage a bunch. Check this Thread as well for fuel economy.
You should be at least in the mid to high 20's on the freeway with that combo.
EC
Always Support Our Troops!
I haven't messed w/ the DFCO so it should be on. I was getting decent mileage until just recently.
1999 Black Z28 - TR 224/224 114 LSA, Comp 918's, TR pushrods, LS6 oil pump, LS2 timing chain, Pacesetter LT's, TSP True duals, Spiral flow mufflers, Taylor 8mm wires, SLP lid, !egr, !air, !cats, chrome Z06's, HPTuners
Also, I can post up a standard log I ran tonight if that would help.
1999 Black Z28 - TR 224/224 114 LSA, Comp 918's, TR pushrods, LS6 oil pump, LS2 timing chain, Pacesetter LT's, TSP True duals, Spiral flow mufflers, Taylor 8mm wires, SLP lid, !egr, !air, !cats, chrome Z06's, HPTuners
Take a look at your O2s and see if they are still switching properly. I recently replaced my O2s and picked up 3mpg. Never did get any of the O2 DTCs.
99 Firehawk T/A NBM, M6, 403, TFS, Harrop, etc
Something has obviously changed... Hmmmm...Originally Posted by tylerdj
I haven't messed w/ the DFCO so it should be on. I was getting decent mileage until just recently.
Time to do some Sherlocking tylerdj
Always Support Our Troops!
Where should I start to look?
1999 Black Z28 - TR 224/224 114 LSA, Comp 918's, TR pushrods, LS6 oil pump, LS2 timing chain, Pacesetter LT's, TSP True duals, Spiral flow mufflers, Taylor 8mm wires, SLP lid, !egr, !air, !cats, chrome Z06's, HPTuners
Load your current tune, then compare it with your previous tune. Use the compare function to atleast show exactly where the changes are. Atleast that way you can make a informative decision as where to start...
Warning: User exhibits tendency to use offensive amount of smileys...
2003 GMC Denali XL
HPTuners MVPI Pro | LC-1 Wideband | 1 Bar Speed Density OS | MAF Delete | Corsa Sport Exhaust | Flex-A-Lite 282 E-Fans | Nelson Harness | K&N FIPK | SSBC Truck-Force 10 Calipers | Brembo OE Sized Cross-Drilled Discs | NGK TR55's
I've compared everything I've changed...most of it soundengineer helped me out with, but I don't know what would be sucking down my gas like it is.
1999 Black Z28 - TR 224/224 114 LSA, Comp 918's, TR pushrods, LS6 oil pump, LS2 timing chain, Pacesetter LT's, TSP True duals, Spiral flow mufflers, Taylor 8mm wires, SLP lid, !egr, !air, !cats, chrome Z06's, HPTuners
Make sure PE Enable MAP & TPS aren't too low. MAP isn't as much of an issue (it's like cocking the hammer) as the PE TPS (pulling the trigger). If you are cruising at moderate TPS (15-30%) to heavy TPS (30-50%) and you're going into PE (o2 sensors go to 700+ and stay there) the TPS and/or MAP PE values are too low.
Log some data & post it here. Maybe we can help or you can email it to me.
EC
Always Support Our Troops!
Here's a log from last night, normal cruising...no WOT.
1999 Black Z28 - TR 224/224 114 LSA, Comp 918's, TR pushrods, LS6 oil pump, LS2 timing chain, Pacesetter LT's, TSP True duals, Spiral flow mufflers, Taylor 8mm wires, SLP lid, !egr, !air, !cats, chrome Z06's, HPTuners
here's my hpt file
1999 Black Z28 - TR 224/224 114 LSA, Comp 918's, TR pushrods, LS6 oil pump, LS2 timing chain, Pacesetter LT's, TSP True duals, Spiral flow mufflers, Taylor 8mm wires, SLP lid, !egr, !air, !cats, chrome Z06's, HPTuners
anyone get a chance to look over my files and maybe see what could be wrong?
1999 Black Z28 - TR 224/224 114 LSA, Comp 918's, TR pushrods, LS6 oil pump, LS2 timing chain, Pacesetter LT's, TSP True duals, Spiral flow mufflers, Taylor 8mm wires, SLP lid, !egr, !air, !cats, chrome Z06's, HPTuners
well, EC Tune helped me tweak some of my parameters and now i'm getting about 3-4 mpg better than I was but it's still not getting close to where I should be.
1999 Black Z28 - TR 224/224 114 LSA, Comp 918's, TR pushrods, LS6 oil pump, LS2 timing chain, Pacesetter LT's, TSP True duals, Spiral flow mufflers, Taylor 8mm wires, SLP lid, !egr, !air, !cats, chrome Z06's, HPTuners
You need to look at the ECT timing tables. The timing is retarded from 185F and colder. What is your idle map in drive? I changed your LTFT map boundaries for yor cam. I set the ECT timing table. Also I lowered the O2 switch points from mode 8 to 16
Your high & low octane spark tables are mostly lower than stock. Same for base timing in drive.
Russ Kemp
Thanks bro. I'll see how that works out.
1999 Black Z28 - TR 224/224 114 LSA, Comp 918's, TR pushrods, LS6 oil pump, LS2 timing chain, Pacesetter LT's, TSP True duals, Spiral flow mufflers, Taylor 8mm wires, SLP lid, !egr, !air, !cats, chrome Z06's, HPTuners
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