Toyota Repair: Camry, cold starting difficulty, stumbles on acceleration, fuel pressure regulator, highway mileage

Question
Hello Ted,

I scanned your q/a responses and could not find one that fit.  Have a 95 Camry 2.2 with 286,000 miles.  I will be putting the fifth timing belt into at 300,000, the car still gets 500 miles on a tank of gas and burns no oil.  Lately I've been experiencing two problems, the car is becoming difficult to start in cold weather and it stumbles on acceleration.  The problem is gradually getting worse.

The car needs to be plugged in below 15F or it will not start, at -10F even if plugged in it won't start.  It used to start easily at -40F, sometimes when not plugged in. When it enters this hard to start phase it sounds like it is misfiring on a couple of cylinders, and if the gas pedal is pumped the engine will turn at about 800 rpm partially firing while the starter in engaged.  Eventually when it does start, it is fine, and can be stopped/started right away without further problem.

During acceleration the car is very sluggish if the gas pedal is depressed quickly, however if the gas pedal is eased up, or depressed slowly to begin with, it will come out of its stumble and accelerate normally.  This problem seems to be noticeable when the engine is warm.

I figure its an emission systems or distributor timing problem (the timing problem is difficult to believe though since the car can be encouraged to accelerate properly and gets good highway mileage). I ruled out the fuel pump, the fuel pressure regulator and fuel filter. The plugs, distributor cap and rotor are new.  I had a recent check engine code of 71 which is an EGR problem.  I replaced the EGR modulator which was very dirty and cleared the code, it does not come back.  I'd clean the EGR valve but it is extremely difficult to access, any suggestions on removing it, a special wrench or something?  

Any suggestions on fixing the two problems that are likely related?  Thanks for any suggestions you can provide.

Cheers,
Don

Answer
I'm not very good at diagnosing very cold climate problems, we just don't encounter them here in SoCal,my best guess would be to try to have the throttle body cleaned and the idle speed control valve cleaned, it's located on the throttle body and has to be removed from it to clean it. The valves can stick and cause starting problems and fast idle problems and stalling. Give it a try.