Poor...real poor MPG's

[ErnestTheGreat]

Picked up an 86 red ranger, 2wd 5spd 2.3L last summer. thing sat for about 10 years on the Oregon coast. Parts replaced last summer to keep it going,

• 
  Drilled out ignition lock and replaced
  Gas tank had visible holes in top of tank so replaced
  Starter replace.
  
  Set a massive cedar stump in the back along with other things, fully loaded the little thing and drove two days all the way to Laramie Wy. Danger averaged 27mpgs whole way, real smooth.
  
  In laramie the cold set in and the original timing belt slipped 3 teeth stoping her. Replaced timing belt. After this, truck ran terrible, no power, fuel economy dropped 10 mpg's on the hwy and in town. Cant even get into 5th on the hwy anymore. Decelerating initiates loud backfiring, accelerating...haha barely able to get out of its way anymore.
  
  Purchased many parts related to fuel consumption
  [LIST2]
  Inline Fuel Filter
  O2 sensor
  EGR valve
  Idle Air Control Valve
  Also MSD coil pack along with new spark plugs and wires.
  Internal tank pump assembly
  
  Now she runs better, no backfiring when decelerating.
  However now sounds like it has a CAM real lopy idle even worse fuel consumption 12mpg in town. Has more get up in lower gears getting off the line but still has absolutely no power on the hwy, hills are taken in 3rd barely going 45 mph with the pedal pinned to the floor. Love the little truck and am frustrated now after investing all this and still runs poorly. Any ideas let me know! thanks.

 

[Mark_88]

Timing sounds like it is out...did you disconnect the SPOUT connector when setting base timing and then connect it back up?

Or is this a vacuum advance setup? Just pull and plug the distributor vacuum to set base timing...then connect back up to test.

 

[RonD]

Welcome to TRS


On the fuel rail, intake, there will be a Fuel Pressure Regulator(FPR), it has the Fuel Return hose attached and a Vacuum hose
Remove and check that vacuum hose for fuel or fuel smell, if FPR diaphragm leaks fuel is sucked into the intake via the vacuum hose causing rich running and very poor MPG.


Yes, as Mark_88 said spark timing or even valve timing could be at fault.
A compression test wouldn't be a bad idea just to take that off the table.
2.3l should be about 150-160psi compression, testing with all spark plugs remove, cold engine.

I would recheck that valve timing was set correctly

 

[tomw]

A bad fuel pressure regulator will cut your mpg to about one half of normal.

If the cam / belt timing is off, the engine may lack power.

If you set the ignition timing without removing the spout, the engine will be gutless unless above 2,000rpm, at which time it will start to have a little power.

You may see a bit of a cut in power and fuel mileage if your new location is higher than the previous. Altitude cuts power and may cut mileage, moreso with a carbureted engine, as it has no altitude compensation. The EFI engines used MAP back then, and MAF later, and MAF & MAP even later on.
tom