Outer Limits 4x4 Board

I have a 93 feroza and the engine warning light comes on if you accelerate hard to overtake or climb a hill but if you back off on the accelerator then the light goes out. Apparently this fault is not registering on the ECU as the mechanic just did a tune up and computer check and said there were no faults. I was thinking it may be a vacum problem? Has anybody had similar problems or can offer some suggestions.

Does it lose power when the light comes on?

I know it is something pretty simple but have you made sure that the battery is secured down properly and it isn't boucing up into the bonnet?

Battery is secure and does not loose power.Have just rebuilt the motor and was doing the same before the rebuild.

Is it the ECU light that comes on? If so, are you sure the mechanic knew how to/ bothered checking? I've been in the situation before where I was told the same, but when I took the vehicle elsewhere every fault known to man was logged....

Check it yourself........ download manual, read, takes all of five minutes .

Then your absolutely sure.