izat

after all it is a 12 valve 2.8l and with driving it like a gentleman it doeas like 4 to 5 km per liter last night i noticed a new issue that on idle the rpm rises to 1100 and lower to 800 rpm randomly even when i press the throttle down to a steady position the rpm shakes up and down

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i went today and asked the previous owner he is not sure if the engine is 24v or 12 v tomorrow i will ask the mechanic who did the swap my car is obd1 and am almost sure that the ecu is the stock ecu and everything is except the cold air intake filter but am sensing that it is some electric problem cause it looks messed up in the engine bay cut and taped wires :/

i drive mostly in city some of the time i drive agressivly flat out no tuning done just a motor replaced like 8 months ago not new motor though its 2.8 liter 24v my car is 1993 but 24v was issued in later years so there might be something wrong or something missing since the woring harness is for an older engine emissions test passed btw the value was 0.5 on 20000 rpm

well i'de like to get 18 mpg am getting only 11 mpg

in fact i like the noise ut makes but does my way of driving drop the avrg mileage by about 60% ?

helpppp!!!! less than 11 mpg my golf vr6 1993 24v 2.8 the mechanic used the co probe and said that the car should do 14 to 15 mpg and from the searches i did vr6 sshould do between 20 to 27 mpg what should i do?