I bought this car with 42,000 on the clock this past summer and the engine ran wonderful. Now that winter is here (Virginia), I have a rough idle. It starts up just fine in the mornings and idles normal. On the 12 mile commute to work, the first half is smooth since I have no stops, but then I hit local roads and the car idles rough at the stop lights, almost killing, even though it's at normal operating temp. Give it a little gas to keep it going, and when the light turns green and I speed up, it does fine again. Wierd thing is, 8 hours later on the drive home, I have no problems, even though the car has cooled off again, and the air temps are roughly the same (freezing + or - a few degrees).

I'm planning on leaving it at the shop in a couple of weeks when I'm on vacation, but if anyone has any ideas, it would be appreciated.

Are you sure the car didn't sit for a long time before you bought it? That seems to be a VERY low number of miles for a car that age and style. (I can't remember that last time I saw a 240 with less then 90k.) Although that might not mean much, it might have something to do with your problem...

I don't know whether it sat still for a long period or not. I bought it from a Volvo dealer, who said it was traded in by an older couple who got a new wagon. I expect they probably used their car to just go to church and the grocery and bingo. The car looked brand new when I took it home. When the dealer's detailing wore off, the only signs of age was slight oxidation of black exterior plastic/rubber.

I would be suspicious of the fuel pressure regulator, although I am more inclined to warn you to be suspicious of taking it to a shop. This kind of little thing is generally solved by the Brickboard given a little input. It is the kind of thing a shop can turn into a cost nightmare.

I have seen this exact same symptom on this board more than a few times now. It usually gets the "do this list of things" answer to fix a general bad idle problem. But what no one answers is WHY is this symptom so specific, so correlated with cold/morning and ESPECIALLY stop signs (Hey DL, if you stop hard is it worse, bet it is?) Regualars will remember the "loaping" thread last week too.

Look, I am finally going to clean the throttle body on mine. I have searched for leaks. I will let you know if the probelm goes away. I have my doubts. My point is, can someone address the transient nature of the problem (though not randomness). If it were a dirty throttle body, leak, etc., wouldn't it always exhibit a bad idle, if not why not?

I cannot do-it-myself much, no garage and few special tools/skills. But I'd like to narrow the list for a qualifed mechanic to look at. I am trying to avoid the money pit. And when you is smart, you get to keeps yo money.

So, anyone willing to help those of us with this problem dig deep into symptoms, beyond the FAQ.

Thanks. I hope that doesn't sound too frustrated. I figured at first it was "just me" with the odd idle problem DL explained, but there are obviously more then one in my boat.

Let the debate begin!! :) I love this board.

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Pete
1993/244/152k

This problem is a true biatch, my car started doing it last winter, and carried on through the summer (so its not cold related)

If I drive the mile or so to the local shop (lazy, I know) then it might splutter on the way there, or it might splutter on the way back (after 20 mins or so of shopping) or it might splutter both ways or not at all.

It tends to happen more in the damp, but it also happens every so often when its bone dry.

The only thing that has never happened it for it to start nicely then go bad after a few miles of constant driving.

The amount of weight I carry makes no difference, the type of petrol I use - 95 ron, 98 ron, leaded, LRP, not tried diesel yet :) makes no difference, neither have any additives I've paid 15 pounds for either.

New plugs/lead/dist cap have not solved it, neither has removing and testing every sensor I can find

To my mind, as a computer programmer, I'd say that its caused by some internal state being wrong at the time of starting. In an engine this can mean something silly like a sensor being shaken by the vibration of startup and sending the wrong signal to the ECU at a crucial time, so from then on the car thinks its in "Winter mode" when it really should be in "Summer mode".

Stopping and starting the engine sometimes makes a difference sometimes not. Its just a lottery as to whether the car will exhibit the symptoms during any given session.

this is an 89 240 estate with 240k miles on the clock. If it works nicely enough in summer I'll sell it while I've got the chance. If not, its curtains for the brick

This sounds like the right answer. This car should need a throttle body cleaning, and not much more. It's possible the air filter's filthy- easy to check. There could be vacuum leaks, so look for cracked rubber hoses. IF it sat for a long time somewhere in it's life, there could be mouse damage- they love to get in the intake, and they like to chew rubber hoses and wires- it's happened and it can be a mess. It's probably more basic than this though, so go through the simple stuff, like plugs, cap, rotor, air filter, throttle cleaning, and see what you get.
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Rob Bareiss, New London CT ::: 86 244DL, 87 244DL, 88 744GLE, 91 244: 808K total