850 Turbo with an illusive jerking problem

[conceptchris]

Hello! I'm new to this site, but hopefully it will help me find answers, and I can help everyone as well!
Well here goes, I'm stumped. I've had volvo's for years and have gotten familiar with all their quirks and demons, but my '95 850 has me scratching my head and wanting to throw tools. For the past 6 months this problem has gotten progressively worse. I've done research and replaced parts and I'm still where I started it seems so hear me out.

When I get up in the morning and drive the 45 minutes to work, the car is great, no issues ever ever ever.
When I drive home after work from time to time it will jerk like all power has been cut from the engine, and then pop right back to life after a second or two as I keep rolling.
If I stop at a store or something after work and then head home it ALWAYS does this jerking thing every couple of minutes or so randomly, also when it does it, there is a smell that i can't identify. It's not antifreeze or oil, but something else I can't put my finger on. The car seems to run just a tad rich all the time as well, but the plugs come out gray/white.
I've also had a problem with the car wanting to die at stop lights if the weather is hot enough. It seems as if when I come to a stop it takes a few seconds for the rpm's to recover to their correct idle speed.
So to summarize, the car jerks at random times while being driven at just about any speed after the car is warmed up, not first thing in the morning when it's nice and cold. It has failed to start a time or two also, but I've managed to get it to fire up after a few minutes then afterwards.

I've checked codes and got a code for the MAF, so I replaced it (the car has 260K but has been well cared for) no difference.
I do research and read read read and everyone points to the cam or crank position sensors, well I figure the car is old enough it will need them sooner or later so I get new cam and crank sensors, no luck.
more research points a few fingers at the TPS, so thats been replaced as well. Here's my list within the past 6 months of what has been done to this car making it an investment I need to fix.

New plugs, wires, cap, rotor,fuel pump, fuel filter, PCV system completely replaced with IPD kit, cam sensor, crank sensor, Throttle position sensor, ignition coil, had catalytic converter replaced with straight pipe, new engine temp sensor, new thermostat, cleaned out the EGR, new timing belt and all front and rear seals. New turbo piping from the turbo to the intake The Tranny was supposedly rebuilt 2 years ago, a month before i bought the car also.

the car sometimes seems to lack the power it once had AT TIMES, but not always and run rich. most of all it is the dying at stop lights and jerking while driving down the road. . . I'm about at the end of my rope with it but I love the car I need to fix it.
Thoughts? thanks for any help!

[da7]

If u have rpm and idling problem did u check the idle control valve?

Did u check the condition of all vacuum hose?

[FCPEURO]

If u have rpm and idling problem did u check the idle control valve?

Did u check the condition of all vacuum hose?

Definitely sounds like a vacuum leak to me. Check the elbow on the left side of the intake manifold. This elbow almost always seems to leak.