Could really use some tips or advice as this issue is driving me nuts. 2000 v70 n/a auto, I’ll start with the symptoms. First start of the day, car always fires right up, no hard starting or anything like that. If I try to drive off after startup without letting it idle for a few, it refuses to go anywhere. Pedal to the floor, I could outrun it on foot, it pretty much just idles forward then eventually picks up a little steam. Creep around the block a few times and the problem goes away, car will run flawlessly until it sits overnight, then it’ll do it again. No codes, timing is fine, no smells, nothing leaking, no weird sounds, not so much as a hint that something is wrong other than that one symptom.

What I’ve done so far. New fuel filter, new coolant temp sensor, new plugs, new fuel pump relay, new camshaft position sensor, cleaned throttle body, new o2s, new cam reset valve, fresh oil change. I’ve checked to see if the cat was clogged, looked for vacuum leaks, tested for head gasket leak, double checked timing, all came up empty. If it did it all the time, it’d make more sense, to me anyway. But it has to sit overnight for the problem to appear. Someone mentioned the fuel pump maybe allowing pressure to bleed off overnight, but the car starts almost immediately, even after it’s sat for a week or two, never so much as a hesitation to fire up.

At this point I’m lost, I was hoping it would join the half million mile club with my 240, but I can’t for the life of me figure this out. Anyone dealt with something similar or have any advice at all? It’s been such a good car to me until now so I’d feel bad not putting in the effort to diagnose it and try to keep it going.

 

did you ever measure the fuel pressure prior to first start, after the cold start, when its bogging and finally when its running good? your model also has the wonky ETM so you may want to read up on symptoms (check out the Xemodex web site). When you looked for vacuum leaks did you simply inspect/spray around or did you have a smoke test done? there's some hard to find lines (like the evap purge that goes all the way back to cannister.

 

That car has the known to fail Magnetti Marelli (sp) throttle body. How old is yours? Is it still the contact variety or does it have a xemodex replacement? Does the throttle plate feel normal when pushed open with your finger cold? With Vida or possibly the correct scan tool you can test the operation of the throttle body.

 

LOL, I called it the wonky ETM (aka the throttle body) because I wasn't sure how to spell Magneti Marelli either. :-)

 

Mine was replaced under the recall so it’s a yellow sticker ETM. It did however give me trouble in the past so I opened it up replaced the tps sensor with the contactless version a few years ago. I’ve got vida coming, hopefully it’ll give me the info I need to sort this out. I’ll be back on here asking how to use it when it shows up lol.