I've been using AutoTap with my 1996 F150 5.8l truck and it shows a "calculated engine load" value of 40-50% at idle. Can someone tell me if this is a normal idle value or do I have a problem here? No codes but engine has been getting lousy gas mileage 7-8mpg and performance is way down.

 

i have a ease software and at 984 rpm my calculated eng. load was 19.3 on 351

 

Thanks for the data point....now the question is what sends the calculated engine load that high?....where to start looking?

 

is the truck running good

 

Runs good and starts easy but gas mileage has gone thru the floor (7-8mpg) and performance seems way off althought this truck has never been a performance champ. New plugs, wires, cap, rotor, coil, air filter, catalytic converter, O2 sensors, timing set at 10 degrees, 82k miles

 

i talking to my brother iam ask him some questions. he blurry94

 

appreciate it!

 

Mass air or speed density?

 

Bone stock 96 5.8 F150 Mass Air

 

How is the short term fuel trim and what is the mass air flow voltage, at idle, in closed loop?

 

With truck fully warmed up I see about 1.05v on pin "D" of the MAF at idle. It looks like short term trims are being read about once per second by Autotap and move back and forth from -2.3% to +2.3% on both banks but spend most of their time between -.8% to +.8%.

 

And that's where you're seeing 40%? What type of vacuum readings are you getting at idle? That and what does the IAC value read (mA or percent).

 

Yep seeing 40-50% calculated engine load at idle. Vacuum is right at 19in at idle. AutoTap shows IAC at 0.2% at idle...approx 700rpm

 

The IAC should be higher than that. Try pulling and cleaning the IAC valve and hook the Autotap back up to it and look for any changes....post up what you find.

 

I pulled the IAC valve and although it looked clean I gave it a good cleaning again. Reinstalled it and it still shows 0.2% but never changes regardless of throttle position. I'm not sure that Autotap is accurately measuring this input. Is there another way to verify it's function?