I only have the issue in drive or reverse at idle. If I put it in neutral it's fine. I've had P0303/P0300 kick out. I also keep getting a P0411 that I have to check out (been an issue before the surging). I don't think it would be a culprit, but who knows.
When I bought this car it had a busted timing chain guide and it also jumped timing causing it not to start. There was no damage to the engine and I replaced the guides/chains. Aside from that I had to change the intake oil actuator since I was getting codes for it. Everything seemed mostly fine after that for roughly a year and a half. I had some surging about 6 months ago but it wasn't this bad, I didn't get codes, and it magically went away for the most part.
I've done my own maintenance for roughly the last 20 years and I would consider myself fairly knowledgeable. With this issue, the first thing that comes to mind is throttle position sensor/idle air control valve. Now with this gen there's only a throttle body and it's drive by wire. I ordered a used TB from ebay just to rule it out (not here yet and from other posts I don't think it's going to work). I did a compression test when I initially repaired the timing chains and they were all good. I don't think it's a compression problem. I would rule out spark plugs because I don't have missing while actually driving. If they were going to misfire, they would do it when there is more load and you probably wouldn't notice it at idle. If the coils were bad again you would have a misfire while driving too. For the same reasons I don't believe it's fuel related, but that could be a further out there possibility. What I would think it would be aside from the TB (specifically the position sensing part of it) is anything that has to do with the system at idle. The pedal position sensor is something I may change, the MAP/MAF would be suspect. It could even be poorly written software that isn't accounting for one or more of the sensors that is starting to get out of tolerance.
Anyone have any further input or experiences with this?
When I bought this car it had a busted timing chain guide and it also jumped timing causing it not to start. There was no damage to the engine and I replaced the guides/chains. Aside from that I had to change the intake oil actuator since I was getting codes for it. Everything seemed mostly fine after that for roughly a year and a half. I had some surging about 6 months ago but it wasn't this bad, I didn't get codes, and it magically went away for the most part.
I've done my own maintenance for roughly the last 20 years and I would consider myself fairly knowledgeable. With this issue, the first thing that comes to mind is throttle position sensor/idle air control valve. Now with this gen there's only a throttle body and it's drive by wire. I ordered a used TB from ebay just to rule it out (not here yet and from other posts I don't think it's going to work). I did a compression test when I initially repaired the timing chains and they were all good. I don't think it's a compression problem. I would rule out spark plugs because I don't have missing while actually driving. If they were going to misfire, they would do it when there is more load and you probably wouldn't notice it at idle. If the coils were bad again you would have a misfire while driving too. For the same reasons I don't believe it's fuel related, but that could be a further out there possibility. What I would think it would be aside from the TB (specifically the position sensing part of it) is anything that has to do with the system at idle. The pedal position sensor is something I may change, the MAP/MAF would be suspect. It could even be poorly written software that isn't accounting for one or more of the sensors that is starting to get out of tolerance.
Anyone have any further input or experiences with this?
