Re: really bad gas mileage
Quote:
Originally posted by drumsk
I have an 88 formula with a 305 tbi recently rebuilt 2000 miles......... I have been tracking my gas mileage and noticed That I am getting 13miles per gallon. Used to get anywhere from 16-17 to 20-21 mpg. The 16-17 was when I had a bad map sensor. This is the worst I have ever had. I just put a new O2 sensor in. Me and my friend were playing with the tbi tonight because in drive I was idling at 1000 rpm now its at 500 which is a little low. But after reading the tech article I know how to set it. How ever when I hooked a computer up to the ecm up to it told me that at idle the map was reading 7ihq??? whic I am not sure on what this means. Is this a low vacuum reading because at idle my engine pull 21 pounds of vacuum...... well any way any help would be appreciated...... tonight I checked and i got 11 mpg which is un acceptable
any help would be appreciated
Kenny
drumsk, you should check the volts of you MAP sensor when you had the scanner on it. you should have full vac. going to it at idle and the volts reading should be around 1.5v idling, and as you idle the motor up the vac. falls and the v should go up to around 4.5 v. WOT. hi vac. will lean it out and low vac. will richen it. that thing should be running bad. sounds like to me you have temp. sensor(the choke) going bad. did you check that.