Elastic throttle ??

[Phil Hill]

First senaro : You're at a junction, foot brake applied, in Drive ready to go, waiting for your opportunity to pull out. A gap appears so you release the brake and gently press the throttle, and the car crawls forwards. You press the throttle some more, still nothing. You apply more throttle, and then all hell breaks loose, you shoot forwards in a flurry of revs.

Second senaro : You're proceeding at a steady speed, on light throttle. Either you are about to overtake or anticipate a change in load, like an incline. Again you gently apply some throttle, and not much happens, you press a bit further but still little or no response from the engine room. Eventually the engine obliges your request in a "boot in the pants" kind of way.

There is no apparent transmission "slippage", no "flare" in revs, in fact the engine revs don't increase initially then do so all in a rush. There are no problems with the engine, it starts easily, is not down on power, does not burn oil, runs correct temperature etc, and behaves normally except for this fault.

My thinking is this is likely to be a sensor problem, most likely a worn TPS, so I've tried another one. Accepting that I didn't exactly go to town with setting it up, and this alternate TPS isn't new so may be similarly worn, it displays similar symptoms, although it is better at initial pull away from idle. We normally run "preimum" fuel (Shell Otimax or Super Unleaded @ 97-98 Ron), I didn't leave the battery disconnected to "clear" the "learned" settings in the ECU.

Am I barking up the wrong tree ?? Before I shell out on a new TPS should I be looking at something else, like O2 sensors, MAF sensor, EGR valves ?? On initial start up we get 16 "flashes" of the Power light but I've not read the actual codes. Any thoughts guys ?? Thanks !!