Okay with you being a mechanic i suggest you get yourself a good code reader ,as on the more modern cars (OBD II) system you need this to help on the diagnostic trouble shooting ..
Just replacing the TPS on a hunch is not always a good idea ..could end up paying for parts that you don't need.
Fuel pressure test is a must with this type of problem .
other typical issue for this to happen is the,
Mass air flow sensor ,
Vacuum leaks ,
Throttle body dirty
Fuel injectors ,(flush the injectors )Ignition coils
Timing Belt jumped .
Crank and cam sensor malfunction ,Code reader or scope sensors for correct working ,no glitches .
But to do this as said a good code reader that has live reading mode ..
This can be bought on ebay uk .
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