New to Modding
 

I'm new to modding, but I have experimented with simple water vapor injection on my old Pontiac Bonneville. It was just a water bottle with a fish bubbler on the intake side and the other running to the carburetor. I got it up to 13 mpg.

Now I have an 87' Ford F250 EFI 3/4T, 4.9L, 4sp. An older friend of mine said it go about 14 mpg when new, but now it is only getting 9 mpg. I'm not seeing any smoke out the pipe and the EGR valve is clean. Unfortunately I do not know anything about EFI systems, so I'm not sure what to check first or how to check it and what order to check things to clear up the problem before attempting any other mods.
John
GoldCrazy2

Welcome to the site John.

The first and most effective mod we always suggest is adjusting your diving technique. Check out our 100+ tips here:

100+ Hypermiling / ecodriving tips & tactics for better mpg - EcoModder.com

I would suspect the oxygen sensor, if that vehicle even has one.

My 89 honda still makes me wonder, pig rich all the time but I'm betting it's because of a less than perfect tune.