working on a 97 f-150 two wheel drive with a 4.2 v6 poor fuel economy like 12 mpg. I pluged in my scan tool and was watching the total ignition advance while driving down the road it was reading a total of 26 degrees an average of about 8 degrees and a low of 1 degree. I called ford they had no idea what the total should be. I know that most GM vehicles run a total of 38 to 42. ANY IDEAS??????

 

I have had the same problem. Same year/engine. Recently found evap return line busted and repaired. Don't know yet if it was the cause.

 

thanks, dont know if that would effect timing either, might be an ecm problem I think 97 was the first year for the 4.2, havent heard of any one else that has the same problem.

 

I remember reading somewhere 8 deg is about right. But I am not a mechanic.

By the way, I meant very poor mileage by "the same problem." I haven't measured timing on this vehicle.

 

What does ignition advance have to do with anything? The computer will adjust timing as needed. So long as the timing marks are aligned properly and the cam and crank sensors are adjusted correctly, there is no need to mess with anything else.

Just give the truck a tune up with OEM spec parts and see if that doesn't solve your problem.

What is the Long Term Fuel Trim on each bank, that is an important value that can actually help you.

 

Is long term fuel trim measured while idling or cruising? Which one would you need?