egale mark, have you tried a 16144288 ecm in your suburbun? i have been tunning a747 on my 6cylender and after tooning it 1 mpg more than the 288 that has a stock chip. there is not as much stuff that you can change but some one that noos more than me may get a lot of mpgs out of this { rage doll ecm } mine is a 6 an 8 is easyer to get what you need.
i am slow and i for got to say tunning the 747 got 3 more mpgs an it run better than it did with the stock aksf chip. been having fun tring to get mpgs and keep the polution standards for this crazzy truck, most things have been changed but not the wiring horness. i noo what works for mine might not work for yours, but if your bored trie a 288 ecm you might add more mpgs than we noo.
What?
The man who says something is impossible, is usually interrupted by the man doing it.
I agree. What? You lost me...
They are the same ECM except the 7747 has a removable netres/LH chip and the 7747 has a much more refined mask/XDF/bin definition so there's a lot more available. Lots should not be touched.
Tell us what you tried? What worked ? What didn't?
I don't like any 6 cylinder bins as they are all Async fueling. I don't like most 7747 bins as they are Open Loop idle or seem to be OL way to much. I seem to do well with ASDU for all including BB and 6 cylinders? Maybe just used to it?
I've never worried about emmissions...
Things that work for me after mechanics are in order:
1. VE fuel correct.
2. Add timing, find knock and back out 4 degrees.
3. Increase DFCO RPM and MAP range.
4. Increase DE percent.
5. HiWay Lean Cruise.
6. Work on Hiway Lean Cruise spark advance by watching MAP lower.
7. Less Closed Loop timer to enter CL sooner.
8. Less choke.
What I have been wanting to do but have yet the time is change Stoich. Fuel now is mostly 10% ethonal and stoich is 14.2 and not 14.7. But changing Stoich only does not help CL, must change O2 Initial and O2 Rich and Lean points. But should we go to stoich of fuel or should we go leaner AFR? There is very little room for this with a narrow ban O2 sensor to be accurate so I need to put the wide band back in Suburban for testing and it's in my 98 Silverado Vortec truck which I am giving up on stock PCM and swapping in a 0411 LS PCM... Since I get way better fuel milage from a 7747 then I can get out of Vortec PCM... but then the Vortec PCM mask is missing lots of stuff! The 0411 LS PCM is well developed.
This may be a good thread to start the MPG tweaking!
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
You understood what he posted? I couldn't even make what he was traying to say.
The man who says something is impossible, is usually interrupted by the man doing it.
Sort of had an idea because of talking with him before, but my first sentence wasOriginally Posted by Six_Shooter
I agree. What? You lost me...
1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
-= =-
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