August 17, 2009I cannot figure out what is wrong with this Explorer. I figured you guys might know...it could be something common. I am not a professional mechanic but I do work on heavy equipment on a day to day basis. My friend has this elderly couple whose 92 4.0 5 spd explorer started acting funny. It runs very rich but is driveable initially. After it warms up and you have been driving it 5-10 minutes if you give it too much pedal it will lose all power. The more you drive it the less pedal you have. Its weird though because it runs smooth right up to the limit...and the limit just gets less and less.
So they asked me to fix it. Well so far I'm already going to have to eat some of the cost because I've changed the MAF sensor and that didnt fix it. I used the old paperclip trick(though I did use wire) to pull the codes. I got a code saying the MAF sensor was out of what it expected the parameters to me. So I look at it...cleaned the pins, cleaned the maf, put it back on, still wouldnt fly so I went and bought a referb one(cant refund for my money as it had a core). NO improvement. I looked around and found quite a few leaks in the plastic piece that goes between the maf and the throttle body so I took that off taped it all up and put it back on. No fix. I thought maybe the TPS sensor was screwy so I tested it and it did have a few dead spots. Replaced that...no fix. I'm worried if i keep running it this rich I'm going to tear up some cats also...
Also took the large vacuum port off of the plastic intake line and blew in it and I can hear air coming from under the upper intake manifold but I cant seem to trace it down.