'94 XLT bogs....

[Defender3]

I appreciate the advice, besides, it will give me something good to do tomorrow; I love a challenge!

 

[Doug904]

As before stated NONE of the OHV explorer's came equiped with a knock sensor, and yes some cam with a camshaft postition sensor mainly the cailfornia vehicles due to their strict emission policy's. The camshaft postiton sensor or CMP has nothing to do with detonation monitoring it just tells the computer where the camshaft is at and when to fire the injectors according to so.
AS for your guy at the parts store its nothng unusual , they usually spit out something they no nothing about anyway. You'd think since he worked at a parts store he have the sence to look it up on the computer and find out this. Of course there again like most it'd probably say unavailable and he's say it was a dealer only item hahaaa
For a quick reference to what the sensors are and do on a 91 4.0....

The one located on the upper intake near the vacuum tree is the Intake Air temp sensor or IAT.

The one directly below the throttle body on the lower intake is the coolant temperture sensor for the computer. It has a two wire connector going to it.

The one directly accross from it on the lower intake is the coolant temp sensor for the guage on the dash. It has nothing to do with the computer. It has one wire on it.

The one located below the power steering pump is the oil pressure sending unit for the guage, there again it has nothing that goes to or has to do with the computer.

The crankshaft position sensor is located down below nearthe harmonic balancer.

If you have an EGR valve....

The silver box on the side of the upper intake that has two lines going to it from the EGR tube is the Delta Pressure Feedback Exhaust sensor or DPFE, it tells the computer when the EGR is open and flowing.

The Round top black valve with a vacuum line going to it and one going to the EGR valve is the EGR vacuum regulator valve or EVR solonoid. This controlls the vacuum signal going to the EGR to open and close it.

Then the Camshaft position sensor located in the very back of the intake behind the coil pack directly in the middle of the block.

That's it for sensors mounted ON the engine its self.


Later Doug904.

 

[chillywilly]

Ok read and reread your post. This might be astretch..but what if you crack your fuel capafterthe bogging starts? Imthinkin maybe the vent in cap might be plugged letting a vaccum build in tank ,dropping fuel pressure. Just a thought seen it on a bronco 2 once ran fine till fuel level dropped then couldnt breathe.

 

[94expo]

Have you noticed the Bogging taking place after you travel 100 miles and Just come off the top of a long upgrade. Mine has done it for some time and it happens after 100 miles and just climb a long upgrade and starting off the other side of the grade it bogs. Not Steap just a steady upgrade. I was thinking O2 sensors.

 

[TPLYNCH]

Are you talking about a large change in elevation, like several thousand feet? Could be the computer not adjusting properly to the thinner air up there... or the FPR could be dumping too much gas, combined with the thinner air causing a flooding condition. Just a thought.

 

[94expo]

Its not Elevation. It seams like after about a 100 mile trip a steady incline that would cause the Ex to run under a pulling / Load condition . Then as you return to a flat surface or relaxed Engine driving condition the bogging begins. With the RPMs at around 2000 it will bog and if you kick it down at about 3000 it clears up. then return to 2000 it will start bogging. Most cases I stop for about 10 min cool of and everything will be fine. Also its not weather. I drove to Vegas from LA twice. 300 mile trip. 1st time 90 to 100 degress outside it never happened. other time 60 to 70 degress and had to stop twice. I have had it happen prior to both trips on local 100 mile trips so I know the problem was there.

 

[94expo]

Its not Elevation. I live in Long Beach Calif and It happened After driving to San Diego. Just prior to getting into San Diego theres a long Incline it happens going down the other side on the decline. then from Long beach to Vegas It happened twice. I think the big thing is long steady Inclines that runs the truck under a load. FRP maybe something to look at.