Just wondering if anyone out there had any ideas on how to improve the mileage on this motor. Truck is a 1992 f-150 supercab with 130 kms, auto trans, 3.55 rear-end. I have changed the O2 sensor, the egr valve and switch. There are no
codes currently up. Truck is currently running 11-12 mpg (Canadian gallon)
8-10mpg ( US gallon). My 89 5.0 with 5 speed manual gets 21-22 mpg (Canadian).
Any ideas would be greatly appreciated.

 

It seems like I set the timing on my truck at just the right time...I have posted on three times already today.. :-)

My timing was way off after a repair at the dealer, getting it right took little effort but produced big result in running conditions and fuel economy.

I would start there.

B

 

Bent Rim
I have the same truck in std cab. the best I have ever been able to get is 13mpg (US)
I have not tried advancing the timing yet but I am going too. I have changed O2 sensor, new exhaust from the y-pipe back, tuned up, fuel preesure regulator, cleaned the IAC motor etc etc. Truck runs great, has never failed to start on the first lick, It just gets poor mileage. Since its a weekend driver I just put up with it. What really sucks is I had a 95 351 and a 97 5.4l before this truck (both leases) that had 3 times the power and got half again the MPG. Oh well ... its paid for

good luck

PS Welcome to FTE

 

Our 96 Explorer is getting about 13MPG. I'm sure there must be a way to improve on that. A4WD, Auto trns, and 115K on the odo. Any suggestions?

 

Just a add-on to post. Changed map sensor. Had the injectors cleaned and the plugs changed.Changed gas filter. And advanced timing 11-12 degrees. No change to mpg's. Also old plugs were almost black, running very rich.

Up to this date these are some suggestions: Put on Flow master exhaust
Put on K&N air Filter
Change TPS sensor
Look into adding a resistor to the wire going into the map sensor, trick it into leaning out the air-fuel mixture

I know the first two will give me a couple of mpg's but at big bucks. Do the last two merit consideration?

I can also use additives to the motor, trans, and the rear-end for friction reduction, but these will only be miniscule improvements to mpg's

 

One cause of running rich would be a bad temp sensor, as in it is telling the ECU that the truck is at a cold temp when it's not. They always run rich at startup until fully warmed up.

Jason