2001 town car

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2001 Volvo C70 Problems - RepairPal

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check you MAP sensor.

check for vacuum leaks

crank sensor are commend problems on this v6 also seen some harness problems on the crank sensor wires

Have your EGR valve checked. I just replaced one on a 95 towncar. It's my girl-friends car. It was $50.00 at Auto Zone. Local shops wanted $300. to replace it.

Here is the common cause of surges, stalls at stops, slow idle speed, erratic idle speed, rough idle and engine hesitation (and other problems), it is in most cases the idle speed control air-bypass valve and or throttle valve and upper intake, these area's get full of gunk and combustion residue over the miles and cause idle issues (stalls, low idle) like yours, Get a can of intake cleaner from any local parts store, not carb spray, intake cleaner, it is made by a company called CRC, remove the air intake hose to the engine, hold the idle high so the engine won't stall, then spray the can of cleaner into the intake while keeping the engine running, use at least 1/2 the can, shut down the engine and disconnect the battery for 5 minutes, then restart and complete a number of mixed driving cycles, town, freeway, stop and go etc., after a few days the problem will go away as the system will relearn to the clean intake.

yes it could be. have fuel pump pressure tested, fuel pump pressure should be. (key on engine off) 1999 to 2000--with egr--41 to 47 psi without egr--52 to 58 psi,

Per your description, I would suspect a fuel pump issue. When the fuel pump is running the pump impeller heats up. On an older pump the impeller can begin to seize up and momentarily stops and starts. Some times it just stops and has to cool down for a couple of minutes, then is ok for a while.
To test this theory, when the engine stalls and stops, your mechanic can use a rubber mallet and hit the bottom of the gas tank, this will free the pump impeller and the car will start again.
Or, have him install a fuel pressure gauge and go for a drive. If the pressure begins to fluctuate and drop, you know the pump is causing the issue.
Good luck, let me know.
Regards,

Common issue at the shop (i'm a ford technician), here is what I do to correct it.
Here is the most common cause of surges and stalls at stops and low erratic idle speed and rough idle, it is the idle speed control air-bypass valve and throttle valve (IAC for short), they get full of gunk over the miles and cause idle issues (stalls, low idle) like yours, Get a can of intake cleaner from any local parts store, not carb spray, intake cleaner, it is made by a company called CRC, remove the air intake hose to the engine, hold the idle high so the engine won't stall, then spray the can of cleaner into the intake while keeping the engine running, use at least 1/2 the can, shut down the engine and disconnect the battery for 5 minutes, then restart and complete a number of mixed driving cycles, town, freeway, stop and go etc., after a few days the problem will go away as the system will relearn to the clean intake.

sounds like your trans linkage needs adjusting.