After replacing the usual culprits, still bad MPG

[LittleJohn]

2.3L 4speed Auto with over 200k and no extra weight besides an aluminum tool box getting 18MPG. When I bought it used a few months ago, I figured it just had old parts and I started to do some tune-ups.

Replaced spark plugs and wires
New air filter
Cleaned MAF
Changed Oil and filter
Cleaned Idle control
Cleaned air intake & throttle body
Replaced fuel filter
Replaced upstream O2 sensor
Replaced rear drum brakes

Still getting just about the same mileage. I have the front brakes sitting in my room to replace, so there could be some brake drag.

I have not gotten it checked for vacuum leaks and I could replace the PCV valve but it's a PITA to get to so have not bothered. How much does it affect MPG?

Any other options to get good mileage out of this?

 

[Mark_88]

You can check for brake drag fairly easily (usually) by simply parking on a hill facing downwards and sit there with the brakes on in neutral. Release the brakes (pedal) and see how fast it moves from the stop position. it should start rolling immediately.

One of the most common brake drag causes in older vehicles is the front flex lines can act like a one way valve when the inner linings are shot. I had that exact problem and as it got worse the resistance got stronger. this was especially noticeable after hard braking from highway driving so that at some lights the truck would almost stall out when I released the clutch to go again.

 

[LittleJohn]

You can check for brake drag fairly easily (usually) by simply parking on a hill facing downwards and sit there with the brakes on in neutral. Release the brakes (pedal) and see how fast it moves from the stop position. it should start rolling immediately.

Thanks, tried it and it did not seem to roll immediately and it felt like something was dragging. Do you think new caliper seals and greasing the guide pins (along with new rotors and pads I already have) will fix it?

 

[Mark_88]

All I can say is it might...and if you already have the parts give it a shot.

The flex lines are not hard to change and fairly inexpensive on these trucks. The most challenging thing is the bleeding of the lines but if you've done that before you will know it's actually pretty simple. I use a One-Man bleeder kit that has worked perfectly for me several times.

The only other thing to check is to raise up the rear wheels (raise both) and see if there is any drag there. If the rear brakes are working properly they shouldn't drag at all but if the drums become out of round they can drag easier.

 

[LittleJohn]

I'll get the front brakes changed soon, I'll consider changing the flex lines even if I can't confirm they are clogged just to rule it out.

I did the drums my self and I'm pretty sure I got the self-adjuster right where the only drag I felt was me turning the diff gears, but I'm not experienced with any other vehicles drag like that so I ended up doing a guess job based on others experience I read about.

 

[Mark_88]

it's actually more likely to be the front flex lines than anything. The rears are self adjusting and unless you did they wrong there is very little that can go south with them and cause them to lock up.

I once had a rear shoe become lodged in the drum and that caused some serious drag. I did a roadside removal and just kept driving (I was doing a paper route). Made it home and repaired it the next day...

Sounds like you have a pretty good idea of how they go in and what might be wrong so I tossed the flex line out in case you've never heard of it.

A common issue with older Rangers...and I drove mine for two years before I learned about it...thanks to helpful people on this site.

 

[LittleJohn]

it's actually more likely to be the front flex lines than anything. The rears are self adjusting and unless you did they wrong there is very little that can go south with them and cause them to lock up.

I mentioned the rear self-adjuster because you can initially set them to have the shoes rubbing too much on the drums. I might try backing it off one click and see if that fixes it. Thanks for the suggestions

 

[telsar]

If its a 1996 or newer look at the fuel trims with a scanner, while its running. Perhaps your fuel trims are high because of a problem. In any event you need a scanner. I bought a cheap one that sends the data to my phone using bluetooth. I think it was $20 and my app was $5.99.