I am getting horrible gas milage with my 87 non turbo it is around 12 to 13 miles per gallon i put a new fule pump and filter and there is a new air filter on it it is not stock though it is after market in take not sure wat exactly cuz i got the car with it. I aslo am having problems with the engine idle sometimes wen it is cold and i first start the car the rpms go up and down from 1000 to 15oo rpms also wen the car is warmed up and is idling the rpms drop to just below 500 rpms and runs a little rough. any advice would be greatly appreciated thanx

 

the idle when it is cold should go up high, that is the accelerated warm up the car came with.

when your car warms up try to raise the idle just a bit, on top of the throttlebody there is a screw,possibly under a little rubber black cap if your lucky enough to still have it. just make sure your car is up to operating temp before you adjust it.

as far as the gas mileage goes i dont know what to tell you. sorry.

 

as fas as the gas milage goes, im making about 17 in the city and roughly 21 on the highway. but it fluctuates based on my driving.

 

lol man i get like 7 to 10 miles to the gallon on my 91 n/a... but im running full stand alone

 

You have a vacuum leak and your TPS is out of adjustment.

Fixing those two should help with the mileage a bit. But the first step after fixing any obvious problems is to perform an complete tuneup on the car.

Don't try to mess with idle adjustments until the vacuum leak issue is solved. Otherwise, you will create more problems.

You need to demand your money back from whoever tuned your ECU. They did a horrible job and should never touch a car. With a full standalone and a tune that doesn't suck, you should be getting better mileage then stock.