BAD fuel economy

[fishbert]

help
im new to the forum and im having problems with my 1990 celica.

basically im getting bad fuel economy, like 7mpg if im lucky. theres no fuel leak and the car runs fine but the exhaust fumes really smell.
ive had a mobile tune up guy out and he says the readings are well over the top to pass an emissions test but theres nothing he can do.
the ecu doesnt want to accept any changes and just adjusts its self back to whats bad.

im really stuck please help

[DarkSideCelica]

u might wanna be more specific..... wat's the exhaust smoke color? is the car running at normal temp always, or does it go up and down? did u do ur regular maintainence? tires properly inflated?

[fishbert]

ok the exhaust smoke is white and theres lots of it but other than that and the extreme use of fuel the car is running perfect. its been serviced well and looked after.
there was a short circuit on the ignition wire about 6 months back which blew a fuse a couple of times till it was fixed but even after that it was more economical than it is now, it just seems to be getting worse.
i dont know what else to put but ill answer everything as soon as i can.

[fishbert]

Does anyone have any ideas? its costing me a fortune on fuel.
cheers

[DarkSideCelica]

fuel filter, air filter, dirty TB, dirty EGR, pcv valve gone bad, etc... too many to list

as for the white smoke, u're getting coolant into the ignition chamber.... basically ur head gasket is going out and tht could be one main reason why ur mpg is so bad

[fishbert]

whats the EGR and pcv valve?

i really only get white smoke while the cars warming up then it seems to go away could that still be the head gasket.

ive only changed a head gasket on an astra, are they straight forward or a bit of a pig? cant be any worst than the clutch...can it?

thanks

[Blane]

Is your celica a ST or GT... 1.6L?

[fishbert]

its the 2.0l gti 16v