Hello everyone. I've had this 240 for going on 4 years and it has been great in general. Usually if there are any problems, they have been fairly obvious and easily fixed. Yesterday, though, when I was trying to go home from work, I started the car, and it died after a few seconds in the parking lot. I kind of shook it off and restarted it, and went on driving. Then it died after I turned onto the road (with my foot on the gas). I was able to limp it to a gas station. I pulled a 1-2-1 code, so I unplugged the MAF. It idled, but very poorly. I didn't want to have to drive it in that state. I figured it must not be the MAF if unplugging it made it run worse. My IAC has caused idle issues before though, so I unplugged it, and was able to drive the rest of the way home (2 miles) without incident.

Now, I've been doing some research on what might be causing this, and the common suggestions are the crank position sensor and the fuel pump relay. I replaced the CPS this Spring or early this Summer, so I hesitate to suspect it. The symptoms it gave me were a sort of unstable running condition, but the engine didn't die. By contrast, the engine runs like a top, and suddenly dies without so much as a hiccough. It seems to me that it is losing spark, and not losing fuel, given that it isn't sluggish before it dies, and it doesn't gradually die, but all at once.

What puzzles me is that it ran for 2 miles after I unplugged the IAC. This leads me to think the IAC is the culprit, but I don't know why a bad IAC motor would cause a stall condition, and not just poor running. This could also be a coincidence I suppose.

I also wonder about the 121 code and why it would run perfectly and then die if a MAF or O2 sensor was at fault. It doesn't make sense to me.

I haven't done much poking and prodding yet, but I am hoping that someone has had similar symptoms before and can maybe point me in the right direction. Luckily I didn't have to work today, but I need my car to be reliable the rest of the week.

Thanks!

 

fuel pump relays tend to be run or not run. they might be intermittent not-run, but there's no condition where they'd make it run but poorly.

random erratic running can be hard to diagnose. air leaks in the intake path, ignition system problems, bad in-tank fuel pump could all cause erratic running. main pump tends to be run-or-not-run.

 

Well, I threw in my junkyard spare Fuel Pump Relay and plugged the IAC back in, and so far it hasn't acted up. I haven't popped the old relay apart yet to see if there's any obvious damage, but it looks like the relay was likely the culprit at this point. I bought a new relay to be safe, as my spare wasn't dated, and the relay in my 240 was dated 2004. Hopefully this problem is fixed. I'll be back if not.

 

Just curious, was the bad relay a Volvo, Stribel, or what?

a real Volvo one looks like


and the Stribel OE one has that same S with )( in a circle that you see on that picture, but not 'VOLVO'. Newer ones are printed on the front rather than stamped on top.

The Stribel ones tend to last 20+ years. The no-namea after market chinese stuff sold nowdays, ugh. 5 years is lucky.

 

The one that came out of my car was a Volvo one. The junkyard part I put in is a Stribel, with the logo stamped on the top in the center. The only one I could get same day was an anonymous black box relay, probably Chinese, though I didn't check country of origin. So hopefully I can use the Stribel from the junkyard and keep the no-name one as a spare.