Alright, I may be dumb, but what are the Map, Knock and Air Charge Temp Sensors for and how would you know if they are bad?

 

Map= manifold absolute pressure. Knock= detects ignition ping. Act= ambient air temp inside intake manifold. Any good service manual has diagnostic info.



2000 XLT Flare Supercab Sport 5.4-Auto-355LS-Tow pkg-Bedrug-Xtang Tonneau

 

My haynes manual goes into detail telling how to detect if they are faulty or at least not performing up to par. You'd need a Voltmeter and a Vacuum gun.

1993 F-150
1989 F-150 4x4

 

what is the little pot vacuam doodad behind the left side fuel rail has 3 screws holding it and a couple vacuam lines, what does it do? Does it affect mileage? my old engine had a new one and I did not switch it on the used one I installed. Trying for better mileage. Thanks

 

That DooDad you describe is the fuel pressure regulator. Yes it can affect the performance of your truck. What kind of mileage are you getting? What engine do you have?

'92 F150 XL 4x4, 5.0L AOD, Headers, K&N Air Filter, 3.55 Gears, LT235/75/15 Tires.

 

I have the 5.0L engine and am trying to find out how to increase mileage. At present only getting 8 to 10 mpg. With a load the check engine light will flash occasionally.I got this engine from a small Broncho. Runs great,quiet like new. This is a 90 model,standard automatic. I hate to start switching sensors as this can get expensive. I suppose a computer checkup is coming???

 

Try reading the codes, you may have a faulty oxygen sensor.
I gained a couple MPG by replacing mine, it was giving me a code for always lean.

88 F-150 4X4 XLT Lariat w/5.0 EFI 5 spd (DAILY DRIVER)
86 Ranger 2WD w/2.3L EFI 5 spd to be 351W 4bbl C4 (NEW TOY- DETAILS WHEN FINISHED)
85 Old Cutlass Supreme 350/TH350 Holley 4160,Edelbrock Performer intake, el-cheapo headers, General Kinetics 270H series cam, 15.588 best 1/4 mile with original 10 bolt 2.41 gears (OLD TOY)

 

the O2 sensor is probably the number 1 sensor that affects fuel consumption the most. but there are dozens of other factors. such as rear axle ratio, driving conditions, tire inflation, wind resistance, engine tunning, etc. If your plugs are light beige, to tan-ish color, your fuel ratio is prob. o.k. A shop will have to do the code check. Don't expect super great mileage from these 302 F150's. Disconnecting the battery for about 5 min. will reset the PCM.

 

The coolant temp sensor would probably be the next sensor on that list-if it is reading cold, the computer thinks it need to run richer like a choke would on a carb.

88 F-150 4X4 XLT Lariat w/5.0 EFI 5 spd (DAILY DRIVER)
86 Ranger 2WD w/2.3L EFI 5 spd to be 351W 4bbl C4 (NEW TOY- DETAILS WHEN FINISHED)
85 Old Cutlass Supreme 350/TH350 Holley 4160,Edelbrock Performer intake, el-cheapo headers, General Kinetics 270H series cam, 15.588 best 1/4 mile with original 10 bolt 2.41 gears (OLD TOY)