Hello,
I have a 2010 GMC Acadia SLT1 with the 3.6l all wheel drive, drive train.
It currently has a very strange issue. The vehicle will run perfectly about 25% of the time- No misfires, no starting issues, absolutely smooth operation.
However... It will seemly go through a cycle. It runs great for one drive, then you park it, start it the next day its running a little rough, then you park it, come back the next day and start it and it's undriveable. Misfiring on 2-4-6, almost no power, any time the throttle is depressed it hardly moves, then if you floor it it begins surging every other second (has power, then misfiring, then power, then misfiring- like you were pulsing the throttle from full to none and back every second). You will then try to drive it like that which is borderline unsafe then suddenly maybe and hr or two of running like absolute crap it will start running perfectly again- this can happen when parked, or while driving it just springs back to proper operation. Then it will start this whole cycle again.
Now... I have replaced the camshaft actuators (all four)- no change
I replaced the high pressure fuel pump, it did run great for one trip, but then returned to the same cycle of poor running and is currently almost undriveable. -Assuming that also is no change.
When observing the fuel pressure in HP tuners I can see it surging up and down with the surging of the vehicle. But what is causing it?
I am getting codes p0089 and misfires for just bank 2 (2-4-6).
It only has 113,000 miles. When it runs great, it is perfect. No knocking, NO timing chain noise, nothing wrong at all. When its running poorly its almost like it should be scraped and a new engine installed.
So, My next step is to replace both fuel rails, all injectors, and the high pressure fuel sensor with known good parts.
Does anyone else on here have a similar experience? -I am quite competent with vehicle diagnostic and repair, but this type of intermittent issue is new for me.
I have a 2010 GMC Acadia SLT1 with the 3.6l all wheel drive, drive train.
It currently has a very strange issue. The vehicle will run perfectly about 25% of the time- No misfires, no starting issues, absolutely smooth operation.
However... It will seemly go through a cycle. It runs great for one drive, then you park it, start it the next day its running a little rough, then you park it, come back the next day and start it and it's undriveable. Misfiring on 2-4-6, almost no power, any time the throttle is depressed it hardly moves, then if you floor it it begins surging every other second (has power, then misfiring, then power, then misfiring- like you were pulsing the throttle from full to none and back every second). You will then try to drive it like that which is borderline unsafe then suddenly maybe and hr or two of running like absolute crap it will start running perfectly again- this can happen when parked, or while driving it just springs back to proper operation. Then it will start this whole cycle again.
Now... I have replaced the camshaft actuators (all four)- no change
I replaced the high pressure fuel pump, it did run great for one trip, but then returned to the same cycle of poor running and is currently almost undriveable. -Assuming that also is no change.
When observing the fuel pressure in HP tuners I can see it surging up and down with the surging of the vehicle. But what is causing it?
I am getting codes p0089 and misfires for just bank 2 (2-4-6).
It only has 113,000 miles. When it runs great, it is perfect. No knocking, NO timing chain noise, nothing wrong at all. When its running poorly its almost like it should be scraped and a new engine installed.
So, My next step is to replace both fuel rails, all injectors, and the high pressure fuel sensor with known good parts.
Does anyone else on here have a similar experience? -I am quite competent with vehicle diagnostic and repair, but this type of intermittent issue is new for me.
