runs at 100C about 75% at gauge. is this normal? i do vist sacramento where its over 100F. my check engine comes on ,I reset microprocesser it comes right backon after a little driving.a few times the car was hard to start after a lot of driving. i dont know a lot about forgin cars. (fuel pump mabye?)

 

100C is ok, not in the "red".

Check engine light keeps coming on because there is definitely something wrong.
It could be as simple as using low fuel octane or dirty air filter, or as complicated as a fuel injection or emmissons problem. You will have to get someone to read the code to give you a general idea, then testing usually narrows it down to about three possibilities. Check all the littlethings first, air filter, fluid levels, vacuum hoses etc.

Blue