Fine Tuned BLM's, now i re enabled EGR, DFCO,PE, HIWAY etc and now truck runs bad

Hello

A little run down of what i have done. First off i got this truck a few months ago and have done some work to it. It had a 7.4L swapped into it. The truck originally had a 5.7L in it and as I figured the chip was never changed. So I modded the ECM with a ZIF socket and put a 512 epprom into it etc. I been tuning off of a tutorial on here. I disabled all of the EGR,DFCO,PE etc... and the truck ran Awesome. I had the BLMs around 122 to 126 for most of the cells. I know I should have enabled 1 thing at a time but I didnt, I enabled them all and the truck ran so poorly I had to pull over and swap in the my old chip where everything was Disabled. With everything enabled the truck is running lean. WB at times shows 18'sthe BLMs as high as 145. I assume the HIway is kicking in and then doesnt come out of it. I checked over some settings and it had some crazy settings like the MPH was set to come on anything above 0mph, it would shut off at a MAP of 75 and would turn on after 10 seconds, so it seems as once it was in hiway lean it would be near impossible to get it to shut down. Anyway I reburned a new program with adjustments and the truck is running alot better but it still goes a bit lean and I dont think it is Hiway mode causing it as when its going lean it seems like its right away. Also it seems like it stays lean too long after I get back on the throttle kinda like the DFCO is still active. I am wondering what settings I should check out to try and fix this issue?

Thank You

Ian

I would do like you were thinking, and enable them one at a time and drivve for a bit. EGR, DFCO, PE, then highway. That should make it easy to find which one is making things go wonky.

DFCO can be enabled anytime you're done dealing with the fuel and spark in the overrun conditions that it would be enabled in. shouldn't cause issues with the AFR at all though.

sounds like EGR, really. PE won't make it head lean and as you mentioned about when it happens, highway mode doesn't really fit either.

I ran with just the EGR enabled today and it ran ok, the AFR would get funky when I get back on the throttle it would go down to about 16.5 and then starts running normal. I think i am going to disable egr and enable DCFO and go from there

Quote:

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Originally Posted by 04hdstd

... the AFR would get funky when I get back on the throttle it would go down to about 16.5 and then starts running normal.

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That is a sign of not enough AE!

There's also an issue of WB AFR driving you nuts with these old ECMs. The WB is so fast, almost instantaneous, where the ECM is SLOW... to save yourself from mental breakdown, or driving off the road watching your WB! :laugh: Re-program the WB and use a 1 volt spread instead of the 5 volt spread, some WB can even slow down the sample rate. Go a step further and use Lambda at 1 volt. It's so much easier.
http://www.gearhead-efi.com/Fuel-Inj...g-using-Lambda

The only time I'd say to use the full five volt spread is a race engine and doing WOT runs. Even then do to placement and the sample rate can be so fast it will pick up in between cylinders firing.

This is why you see 8 individual WB sensors and 8 EGT sensors at some engine dyno shops.

Thank You everyone,
As of today I been running with DFCO, PE, and the Air Diverter Enabled. Hiway Lean and EGR are Disabled. The truck is running really good. AFR's are rock solid. I did add some AE as Eagled pointed that a lack of AE may have been causing some issues. I do have some questions tho. When I was running with all of the above disabled, my average BLM were all lower than 128, mostly running 120 to 126. Now that I enabled all of the above, I do get a couple blocks that are always around 130ish. Is this normal? Should I adjust my main fuel map?

On the DFCO, I seen there are adjustments on when it kicks in and off such as RPM, MAP, and MPH. Is there a hierarchy with these settings, Example say MPH overides the map or rpm settings?

Is there a way to soften the DFCO? when in lower gears the DFCO is very noticable almost like a jake brake goes on.