Surging @ Idle And Part Throttle :(

[t8fanning]

It's not too terrible to take it off without a tool, especially the second or third time. Here's the process If I remember correctly, push in, don't pull the pink things out. Takes 5 min maybe.

[jschaefer7406]

Thanks guys.

Have taken it out before without the tool, usually like to have it to make sure it locks back in securely. Have done it though with a butter knife and screwdrivers .

Seafoamed the girl this morning, no change. Did it through the intake twice (drove in between obviously ), nothing in the oil or fuel. Will add the Techron for a long trip tomorrow, hopefully it helps.

Also checked for intake leaks with carb cleaner, no dice there either .

Thanks,

Joe

[DanielCamer]

I had the exact same problem on my '99 S70. Turns out it was my coils. I scanned my car and it said Cylinder 3 misfire, but in fact it was the coil in cylinder 4. My advice, grab a set of spare parts from online and always have them handy for diagnosing engine problems. I'm grabbing a new coil, injector, plug, etc. for next time. Diagnosing this time was HECTIC.

Mine was the coil. As soon as I swapped it, ALL surging stopped.

Check your coils. Make sure you don't buy one from your mechanic, grab one online for nice and cheap. Go Bosch or OEM.

Hello all,

My '00 S70 AWD has an ongoing idle surge that is now occurring @ part throttle as well. Cannot be seen on the tach, but pretty obvious on the boost gauge:



Now, before everyone starts to blame the ETM, let me say that it's already been replaced. Was done just over a month ago (genuine Volvo unit, also happened with a good used unit I had run for a bit before going new). So, has done this with at least 2 different ETM's (all had new gaskets, etc).

Have also swapped out the MAF with a used unit, no change at all. I have visually inspected for vacuum leaks, but have no way to pressurize or smoke test. Not ruling out a vacuum leak, but vacuum is very high also (22" or so warm idle in park, 27" or so on full decel). All usual hoses are replaced with silicone (CBV and TCV hoses). No DTC's either, and ME7 is usually pretty finicky about vacuum leaks throwing fuel trim codes.

This seemingly began when the original ETM started to die and the good used unit was swapped in (original ETM had intermittent throttle response and limp mode, no idle problems whatsoever). Also replaced the B+ cable (battery-to-fusebox) that weekend, but that's all. Nothing in there that could have been disturbed to cause this. At first was mostly noticable @ warm idle in park/neutral (not cold or @ throttle). Now is noticable under low-load throttle, like in a parking lot or on the highway with the cruise set. Can actually feel a slight surge in the car, as well as seeing it on the boost gauge...

Not sure what else to try . Would a failing front O2 cause this?

Thanks,

Joe