This vehicle is bone stock original, it has a dead band around 60 - 70% throttle that I have been chasing. The following statement is what I have found as the cause, any input on obtaining a chip or complete ecm that does not have this trait would be appreciated; "After a long delay, I finally took a 2 hour trip with my laptop on the dash in gauge mode running TunerPro V5, what I observed confirmed that the dead band is indeed a result of spark advance being pulled, BUT....... It is not a result of knock count, which over the course of a 2 hour drive at freeway speed including a few pulls up grades, the total knock count only increased by single digits. Here is where the problem lies; Contrary to common knowledge on how an egr system would work to cool combustion chamber temps under hard load, what this ecm does is that past a certain percent of throttle opening,(55-65) modulation of the egr goes to zero (no egr) and at that exact time the timing advance drops from, depending on load, from 25 to 30 to as low as 12 degrees. Now, how can an engine spinning at 3200 rpm at 80 to 90 percent throttle opening make any horse power and torque with 12 degrees of total btdc advance, answer it can't ! I could pedal the throttle and watch the egr and advance toggle on / off, up / down and feel the power follow suite. So, with the new insight, it would appear the only cure would be to have an ecm the didn't have this way over the top engine protection function.
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Originally Posted by dave w
Don't force it, get a bigger hammer!
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