Little background, the 8 plug 2.3, 139K, 5spd, in a 92' 2wd Ranger ext cab.
Problem is this, gas milage has been declining over last two months to about 200 mpg per 17 gals, seems like the motor is struggling for air, my first thought is egr valve and intake ports clogged. Have MIL light lit, but when I hooked up scanner said no codes temp or perm stored. any thoughts from the masses out there? Would like any and all advice before I start throwing money at this thing.

Thanks to all
Ammo Troop

Moderators, not sure which forum to post this question in, please move to correct one if needed

 

Plugged cat...

SteveL

 

Guess I should of stated the Cat was removed by previous owner...sorry

 

That would have helped with the diagnosis, pull the
vacuum line to the fuel pressure regulator, Got fuel??
replace... The check engine light is a warning that
something is amiss, no codes is a little worrying tho...

SteveL

 

Thanks, were is the FPR located on this truck?

 

At one end of the fuel rail...

SteveL

 

Found FPR, no evidence of fuel in vacum line, will this trick work on Fords? I know it does on Honda vehicles, apply 10-12 ponds of vacum (with vacum pump) on intake side of egr, if EGR valve is working correctly vehicle will have a hard time idleing, (stumbling and such) For some reasons leaning towards carbon clogged intake ports or faulty egr valve, probably way off track, but just a hunch.....
Thanks
Ammo Troop

 

Yeah, this happened to me about 125K on my Ranger. I attributed it to the crappy gas i fed it all its life. Run a good fuel injector cleaner (not the cheap stuff) through two full tanks of good (premium gas). Then if its still sucking down fuel, replace the EGR. That cleared up my rough idle (which 4 separate mechanics told me was a worn out engine/dirty air filter/bad plug wires and a "carboned up throttle body".

NOTE TO PROFESSIONAL MECHANICS: If you don't know for 100 percent what the problem is ... don't guess with new parts ... just tell us y’all don't know for sure and give us our options.

I did my "Italian Tune Up" via the two-full tanks method and the EGR and it ran like it did new. Pulled hard to 5500 in first, 5200 in second and 5000 in third. with rubber on all three.

... course then the oil pump crapped out on me at 150K, but that's another story.

J Frosch
91 2.3/5 Spd XLT

 

Hello Ammo Troop,

My 90 Ranger had declining fuel economy. The High was about 27 for Freeway Only driving, and went down to about 16 with the same type of driving and with a Check Engine light. The code represented a Lean condition.

To make a long story short, I guess that as the oxygen sensor ages it becomes "less sensitive", therefore it keeps adding more and more fuel to satisfy this "less sensitive"condition. It will do this until the sensitivity is so low that it is allowing the injectors to provide a maximum amount of fuel to the engine.

The next step is that the sensitivity of the Oxygen Sensor goes even lower to a point that it turns On the Check Engine Light. In my case the engine was blowing Black Smoke and was reporting a Lean Condition.

Once I replace the Oxygen Sensor the problem went away immediately and my fuel economy returned.

I do not know if this can help for your situation. Many on this site are Eons ahead of me in knowledge about these vehicles. But this was one of the things that I had a problem with about 2 years ago.

Best of luck

Gary

 

I had a mustang with the daul plug motor that had similar problems. I replaced the timing belt,o2 sensor & throttle position sensor. it ran like a new motor after that.

 

Update, Found the cause of the check engine light, two of the vacum lines running from vacum tree across engint to actuator had broken in two, undetectable in the wire loom, repaired these, pulled egr and unplugged intake port as best I could, bench tested egr for vacum leaks. After test drive 30 miles, light remains off and power seems somewhat restored. Going to pull intake and clean throughly real soon, along with screens on fuel injectors. The electrical plug on the egr, what does this serve? pulled the plug off and no change in engine at all, or does it only function at road speed?


Thanks
Ammo Troop

 

The tape is there to keep the valve from being opened to far. Or at least that what I was told.

 

the electrical plug on the egr is the egr postion sensor. the ecm uses this sensor to monitor the opening and closing of the egr valve. the egr valve is not functioning at a idle.

 

Gas miliage went way south after above mentioned repairs, to the tune of 100 miles to 1/2 tank of fuel...OUCH. So I figured the injectors are clogged or a chunk of carbon got into the intake somehow, pulled the upper intake and fuel injectors today, cleaned the injectors and screens, cleaned EGR, IAC valve, cleaned throttle body, finished cleaning EGR port (used drill bit) The electrical valve on the passenger side of the engine compartment, the one that connects the EGR vacum with the Vacum tree, when is this supposed to actate? and what is it called. could not get mine to actaute, tho' there is power to one side of the electrical lead going to this switch,


Thanks
Ammo Troop

 

Thought you would like to know that the electical lead does not actually actuate anything (it sends a voltage signal to the computer, and then it is sent at a certain rpm under load if under the load or rpm range there is no changes in computer commands), It still works by vacuumn. Just a thought,---- but this is not your prob look elsewhere.
Did you check the codes on the computer? Try there 1st then just a thought how old is the belt.
Too many times does the wrong component get blamed for one that is not at fault.
Anyone better experienced with the 4 banger care to help here? Or tell me I am wrong?