G13 engine ..throttle response .

I didn't want to high -jack the other thread about 13bb engine idle, though maybe it could be the same issue , or just a tad simpler.
our problem is ..the car starts fine ticks over fine , blip the throttle fine,  but ..it was occasionally but now more frequent , the throttle stays on a touch when you lift off to change gear, it dosen't Rev , just dosen't come off instantly . It isn't every time , it isn't from cold  or hot   It isn't when you've got the pedal to the metal    .
  I tried lubing the linkage and it worked ...for a while ..coincidence ?   This motor is due to come off the road at the end of the month for a service while another is being used , so we can live with it for now .
  Oh forgot to say EML has never lit up ever , suspect no bulb! & on last MOT the chap mentioned it just scraped through on emissions. 
 Though I would swap throttle cable anyway as its a cheap start along with crossing digits and becoming religious for a moment 

Does the return spring stick or has lost it's "springiness"? 

With my over idling if I grab the semi circular bit the cable sits round and twist it back the revs do drop... so I've ordered some "Intake Valve EGR IAC Throttle Body Cleaner" to clean the throttle flap and the idle control valve, thinking something might be built up inside the throttle body  with age...?

I'll give the spring a good clean and re-lube too?...

The throttle response manually from under the bonnet is fine sadly ..as this would be easily sorted . So I cleaned inside the throttle housing , there was a bit of oil which is obviously from the breather , thought that could be the issue......fine for a day , now normal service resumed with a bonus touch of a blip of the throttle while standing next to an idling jimny!

I suspect I need to change the TPS , but are the M13 and G13 the same , if not can someone recommend an affordable one . As in not paying to much for a part that it isn't at fault.anyway .