what was your original MPG and what happened to that it changed?

 

When I bought the car, it had been sitting for about six months. I bought it knowing that it needed work. I had to respray the duco, it was outside for the whole time. was overdue for its 40,000 service. The engine was hunting and surging but idled real good. So I took it straight for a service and my mechanic ran a Diagnosis. At the time he found the O2 sensor was faulty and the MAP sensor as well. I never had a chance to see what gas mileage it would get before that. (the previous owner had no idea about cars).

I took it from there and it was smooth to drive but when it was warm there was no power and I got 15MPG on the Highway. So I took it back a week later and we completed another Diag. He found that the Temp Sensor was reading ok but altered from time to time, so we replaced that. My MPG went to 20miles, I had loads of power and otherwise seemed fine. He had the car all day and drove for 4 hours on and off to see if any other faults would show, but nothing has, so MPG is still 20.

The only filter not changed is the Gas Filter, and the only other thing I notice is that if I pull up to a light and put the transmission in neutral before the car stops rolling the revs go from 1000 to 1300 for 1 Second.

This made me think the o2 and MAP sensors are wrong but they are less than 6 months old and it would show again on the Diagnosis test. As previously noted the Plugs and plug wires are new as well.

 

Kevin, I just noticed this other post you made a while ago. I wondered if my computer will tell my mechanic the actual air fuel mix?
its BS u can not increase MPG with a spark plug on a Speed density system the computer regulates the fuel so anything that is changed it will simply re adjust it back to 14.1 air fuel mix.

 

I cant answer that I don't know what tools or scanners you guys has plus if he sees it no idea if he will understand what he is even looking at.