I met Flyinryan on this forum and he offered to take a shot at tuning it using my SCT flash pak. His first test file right off the bat was a WORLD of difference the idle was solid rock stead at 800 in or out of gear, fires right up on the first shot every time, runs great even cold then switches to closed loop at proper time/temp without a single hiccup so no more 10 minute idles to warm it enough not to stall out in the mornings. And it just flat out sounds and feels great. Even with my large cam which only has 10" of vac at a neutral idle the truck doesnt rock or shake, just sounds like it wants to tear the wheels off
!. The first test drive was amazing, super solid off idle response, pedal is quick and snappy it pulls so effortlessly now to 75-80 without even breaking 2000 rpm, this is a heavy 4x4 with 3.73 32" Goodyear Kevlar Mudders and a 4" lift and a cam that really does not make power until 2500 RPM. My fuel econ way up from what it was in traffic around 10-12mpg and now its a solid 17mpg on my morning commute. Getting the timing mapped correctly is mega-important. Stock timing algorithms wont work well on a modded motor and previous tuners just locked it at a fixed 32 deg which is crap. Any old timers out there ever lock out both mechanical and vac advance on a distributor and just set timing to 32 deg from 1300 RPM Up??? I certainly would never do this on the street.
Whats this all mean..... AFR is just a portion of the game, the acceleration enrichment, timing maps, dashpot, cold idle, warm idle, scaling the curve to match the vac signal of the large cam and best of all being able to control when you want open loop to kick in but still retain closed loop for idle/cruise and light throttle economy. Ryan is able to trick the ECM into commanding a slightly richer than 14.7 even in closed loop large cams like that added fuel so they dont surge,skip at light throttle cruise etc.
I can go on and on about the difference this made to my truck. Having someone who understands this JTEC PCM and can make it do what we need to match the awesome builds on this forum is worth more than I can surmise in my long winded post.
Ryan has built me 4 files since last night and using my feedback from my Innovate LM2 datalogger he has made improvements that I frankly didnt even think were possible, and were not even close to done, taking baby steps and making certain everything lines up and one change does not negatively affect another area etc. Guys who have cammed up OBD-II setups and have not properly tuned it, give up on timing / map adjusters your barely scratching the surface of what can be done.
Once were all done I will dyno this monster, but best of all driveability!!!
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