- At moderate speed (60 MPH ish), flooring it frequently results in unsteady acceleration until >5500RPM. It kind of lunges then pauses then lunges then pauses on its way up. This doesnt happen every time but its frequent.
I've seen this before. It's related to throttle control somehow. Remember the ETA only goes beyond 1/2 opening electrically; the throttle cable only opens halfway, after that it's throttle by wire. Seems the butterfly is opening/closing slightly about once per second, resulting in the surging. Has your ETA been rebuilt/replaced? Also, it's possible that a vacuum leak could cause something similar - any chance you can perform a smoke test on the intake, or at least trace down every vac line including the PCV tubes?
- At idle, the car frequently stumbles. This happens in particular when hot; ie drive on highway for 30 mi, get off and the last 2-3 mi on surface streets at stoplights the car feels like its about to die. It sometimes even shakes the full car. It sits right at 500RPM in D or R. P is 650RPM.
How old are engine mounts, what spark plugs were gapped at 1.0mm? Viewing live data on SDS HHT-Win will confirm if it's a misfire, or something else, if you can view the data while the problem is occurring. Do you have SDS access? If you can confirm this is a misfire, then you know what to work on next - or what to eliminate as a possibility. Note that bad engine mounts will make the idle feel rough (shaking the car), but will not cause the engine RPM to drop below spec (500 or 650), and won't cause the engine to actually die. Oh yeah - have you confirmed it is not a leaking EGR valve? That will also cause a rough idle.
- Then, at low speed under load (esp pulling away from a stop sign) it feels dead from take off until about 1500RPM....I tried to capture this in the video but it feels very lethargic and sounds almost gargly.
Need live data again - look at the adaptation values. Should be between 0.900 and 1.005, if not, something is screwy with mixture. I'd also check MAF live data. As a rough test, disconnect the MAF (yes this will cause fault codes) and see if it drives better or worse. Clear the codes after reconnecting the MAF.
- A similar feeling can happen when pulling onto the freeway from stop....it sometimes refuses to kick down to a lower gear and just bogs until it wakes up above a certain RPM.
Shifting issues would be completely different/unrelated. The transmission will downshift / kick down to a lower gear only with enough throttle travel (Bowden cable adjustment), AND also below a certain RPM/MPH. Alternately, floor it so the electrical kickdown switch is activated, see if there's any change.
Im at a bit of a loss. Fuel pumps were done in 05 at 175k mi (245k mi now). I could do fuel pumps/filter, I could do O2 sensor, I could do caps/rotors again...but Id love to try and feel more definitive before throwing more parts/money at this.
Fuel pumps are unlikely, the symptoms don't match... low rail pressure results in a smooth loss of power, not rough running. I really don't think that is the root cause here. I wouldn't mess with caps/rotors unless HHT-Win live data from EZL shows certain cylinders misfring.
What DTC's keep recurring, and what is the DM code causing the CEL right now?
