DPFE sensor and 4R55E link

[cj111]

Many moons ago before cat converters, I use to repair vehicles and found it interesting how many high-end Pro mechanics started out as DIY guys and learned alot. A few years back we purchased a 1995 Ford Explorer Sport 4x4 4.0 liter with a 4R55E trans for the kids. It was in very good condition and someone has taken care of it(except for waxing the car) and the mileage was 130,000 miles. 1st thing I found was a timing cover gasket leak and I changed that (outside in -15 degree weather) and installed a new timing chain with double rollers. Then came spring I looked at the throttle body and found a heavy accumulation of exhaust gases at the plate. Then after poor mileage and a small leak at the head gasket on the passenger side I decided to pull the top end off and have a look. First the gasket was very bad shape on the passenger side and the drivers side not far behind. I then pulled the valves and inspected the surfaces to find acid type pit etchings on all the valve seats and on the valves. I lapped both surfaces to see if this can be removed or reduced and they cleaned up enough to reuse except for 1 exhaust valve where the head gasket was blown. Now all of this started from trying to find out why this thing had bad mileage, but started and ran fine. I found a site called AA1Car.com that has excellent test and description info to help test the DPFE along with almost everything else you need. The test always checked out ok after testing Map sensors and all others.So I then read the info on DIS Ignition Systems and the Wasteless coil. According to the site that coil can only funtion properly with a set of Irdium Spark Plugs. All others will start to fail after 3 months or so affecting the computer-oxygen sensors-converter-and THE TRANSMISSION because of the direct connection to the backpressure of the exhaust. I know because I pulled the converter(it has 2 in a row) and sure enough the front half is totally plugged and the back converter is clean as a whistle, even after running Seafoam through tank.My next step was going to be CATACLEAN, but after a close examination it would have not worked. The trans has just been rebuilt prior to our purchase and a Transgo Kit installed. But someone forgot the low/reverse servo spring and after I dissembled the valve body decided to install a new valve body because of the wear. All the solenoids check out on ohms(EPC-TCC and Shift Solenoids)ok. Here's the strange thing I have followed all the test with only a ohm-volt meter, very little tools ( enough to repair a lawn mower-Maybe!), and a dozen guys are stomped but the first thing I did when we got it was to put my hand at the back of the exhaust and feel how much pressure was coming out and my first thought was the exhaust was plugged. I am going to verify the backpressure and DPFE function( have a new one to install) with the cats removed and a temp pipe installed and see how the performance works out and then install a new converter a little farther back ( universal) and test the system. Along with a new valve body and the exhaust replace and excellent compression and DPFE I am guessing that even a Spark Plug that shows as a replacement can be wrong even when doing a normal routine as a tune up. I guess the cost can be more costly in all parts of the car and take a little more wear and tear than needed. I will let you know what happens when the rest of the parts arrive and she's up and running again...ps..Alaska is a little colder in the winter then Florida and snow is not gasket material !

 

[cj111]

Visit the COUNTERMAN.COM website for more info...Update After testing the voltage at PDC box under hood and having 11.54 volts compared to 14.64 volts at the inside fusebox. I decided to remove the alternator and have it tested at Autozone. The test all past except for the Lamp/OUT test. The Lamp/IN test past. The reason was given that a Diode must be bad. Went home and carefully pulled the Alternator apart and found no damage any where inside. Tested diodes and they all passed. Decided to clean the internal parts with Electrical cleaner and reassemble after making sure the unit was dry.While looking at the brush end of the armature I noticed that the inside area where the brush rides had a grove cut in it from the brush, this may have been a problem, not sure.After reassemble I tested the voltage right away at the PDC fuses while running, the first test showed 13.64, and after turning off and restarting I then had 14.64 at the PDC box fuses. I ordered a new 130 amp alternator and installed it and now my voltage is at 11.94 at PDC box fuses...New TPS also and even though it tested good, I changed it. First road test it ran great shifted perfectly and then after a few start and stops it started again with variable shift patterns. Yesterday I tried the throttle cable mod that is posted here and this is what I found. First I placed a long pry bar between the seat and the gas pedal and moved th seat forward until the pedal was completely depress and then checked the butterfly of the throttle body. It was only opened 2/3 of the way, check the cable and all was fine , went under the dash board and installed 2 zip ties ( that is what was needed to have throttle body fully open with pedal to floor and no binding on cable. Then I tried the so called TPS mod with drilling out the holes on the TPS. The brand new Standard part was at 1.59 on the middle wire ( gray/white, the top wire Gray/red is ground, the bottom wire Brown/white is the 5 volt feed.). I drilled out the metal sleeves no problem and could only adjust to 1.34 at the lowest. I left it there and went out for a road test. The Zip Ties worked, the shifting corrected itself with driving about 10 miles, by then the overdrive kicked in properly and the upshifts were normal and the acceleration was very good. The first shift going up a hill was the way it should be without any lag or any hang ups to upshift. The only other thing I also did was to put a ground connection to the Gray/Red wire (ground) to the bolt on the air conditioning mount, being it went straight to the block and not to the plastic manifold. Now it is just a matter of checking the mileage and verify all is correct....

 

[cj111]

Update: She drove it this weekend up to the Glacier ( we have them up here). temp at the house was about 30 above( warm for this time of year), and about 10 above at the Glacier. She put on 124 miles from fill-up going to and returning.She was probably in 4x4 high mode because of the slick roads from the rain and freezing conditions.The amount of fuel used was half a tank , so I guess going from 100 miles per tank to 124 per half so far is better but not what I would call normal.If you take 15(MPG) x 18 gals ( fuel capacity ) you get 270 miles per tank, at this time the average is less than 14 and that is highway...Now the next step is to see if the Keep Memory Alive part of the computer is actually working as designed. I have not yet found the source of the learning mode for the computer to store the needed parameters, except for oxy sensors,camshaft sensor, crankshaft sensor and transmission speed. All new sensors,so in theory all should be OK. I may go back into the dash display and check for pin connections even though everything works ok...