4.0 engine problem

[Bird]

Rangers used a return fuel system w/ external regulators until 98 when they went to a returnless fuel system with the regulator in the tank.

Bird

 

[jds3403]

Hello, hopefully we can get back into running shape. So you say that the probelm is intermittant, well what does your exhaust look like while the problem is occuring? is it black white blue? have you pulled your plugs to observe the color? the only way to accurately check them is to pull them put in some el cheapos or clean them and putt around town NOT @ WOT and go back and pull them what do they look like? Black? Tan? White? this kind of sounds like an injector problem. Some of the injectors might be sticking due to old age 1996-2008=12 yrs and/or repeated heat exposure. Those 19 pounders are known to malfunction @ old age/high mileage. the computer cannot compensate for illfunctioning equipment hence the poor performance, also could be a vaccum leak but i doubt it as the way you described is like it runs fine and then starts to develop problems which is NOT the characteristic of a vacuum leak a vacuum leak will cause you problems ALL the time unless it is small enough to be absorbed by the surrounding expanding metal but this too is highly unlikely seeing as we are talking expansion rates that are almost invisible to the naked eye , talking thousandths of an inch if that and that is why gaskets are made in the first place to absord the defects in the metal. Again if you had a vacuum leak you would notice it as soon as you start the vehicle because it would run like shit, surging idle constant "feathering" of the throttle to keep it running until the computer can "try" to compensate for it. you did not describe this. So vacuum leak out
Now for the conditions you did describe, if you did all the fuel management work you say you did, then the part where you said the new air filter makes run even further like shit leads me to believe that your af ratio is getting even further to the lean side which can be caused by malfunctioning equipment. and by the way buy a manual and a decent multi meter as this will be far cheaper than buying uneeded shit. because when you buy this stuff that does'nt fix it send the stuff to me J/K. To test injectors isn't hard and to replace them is even easier! pull the injectors observe the pins and rig up a "connector" what ever it may be and use small 9v battery to apply voltage listen for the solenoid to energize should hear a click if not junk. if the "click", sounds abnormal as far as hesitant, grinding, quiet, junk. look on ebay bosch 19 pounders are cheap. if this is the problem. Sorry if this does not help but the info left on your part is not very helpful either.

Jeff Snyder

 

[fes007]

I'm back

I've noticed that my truck seems to do this more often in damp conditions. I just got back to driving in recently and I am still not too sure what the hell is wrong with it. Is there a link online where I can find the ohm and voltage readings for sensors? Any help in figuring out what is wrong will be helpful from anyone.