lt35 power loss

[yelova]

now i have my new engine run in, and oil and filter changed properly i have developed a power loss whilst running, all seems to be going well, then i slow down for traffic or a roundabout and lose power. turn the ignition off and on all is well till i slow down again.
can anybody help please

[rayl]

Hi Yelova, had same kind of prob for a long time, would cut down to about 50/55mph plus no pulling power till turned off and started again, had the air mass valve on top of air filter inlet tube changed not had a problem since

[Dunk]

Could be overheating due to dodgy thermostat, I had a similar problem.

[yelova]

thanks rayel and Dunk
AMM is 18 months old,had it checked by v/w 3 weeks ago they said there's no problem showing on computer,sugested turbo fault,they want three hours to check that out £££.
Engine is new,i assume they fitted a new thermostat (could be kidding myself) it runs slightly warmer than the old engine just above halfway on the guage. do you know what temp it is supposed to run at.