1995 Ranger 4.0L 2 wheel drive ext. cab - 171K miles.

New purchase - I have never driven on the road- needed trans work done first- but now ready to go on the road But.....

She runs rough and in gear starts to sputter as I push on gas. I did the minor things while trans was out (fuel filter, Plugs, PCV, Air Filter, Oil chg., cleaned all the sensors I could -MAF, IAC, couple others on top)- codes it has now are P1400, P0135 (02 sensor).

I actually disconeected the MAF yesterday and it ran the same?
What does that mean..

Please any help would be great.....

Thanks

 

You've been busy on this one.

Post All trouble code Numbers you have.

The P0135 is for the bank-1 upstream before cat O2 sensors heater circuit & that could cause it to be late heating up & the sensor coming on line as soon as it should. If the sensors have over 100K miles on them, its time to consider replacing both upstream sensors, as their switching speed slows down with age & both should be matched to make the engine power balanced in both banks.

The P1400 is for the DPFE sensor, it supplies feedback to the computer for EGR control & its a common problem part.

On the MAF sensor question, did you let it cool before cleaning, used a non residual product whos recipe is just for cleaning MAF sensors, like CRC, or Valvolene MAF sensor spray cleaner, was careful to not touch the wire electrode with the spray wand, or otherwise damage it while handling & kept it squeeky clean upon re-installation?????

Are you certain the plug wires are routed correctly, using all of the factory wire looms???
If so, raise & insulate the coilpack from ground & see if you get a positive change. If you do, suspect the coilpack has a crack underneath, its a common problem with coilpacks.

If no joy there, seeing as how you didn't mention replacing the plug wires, look for arcing & sparking from them after dark & or do a "wet down" test with a spray bottle of water along each wire, looking for a light show, or idle change. If still no joy, do an end to end resistance check. With 171K on them, I'd consider replacing with a Motorcraft wireset.

Some thoughts for consideration, let us know how your trouble shoot goes.

 

Thanks so much for the information so fast-
Cleaning the MAF- the truck had been sitting for weeks when I cleaned it with MAF spray and q-tip, took the whole thing apart out of the Air box.
I just wonder why it runs the same when unplugged.

Plug wires- I put back on as they were taken off- but who is to say they were right- they do go in the holders nice I will have to look into that. Last nite I did spray the wires and coil with cleaner (some cheap stuff I had lying around) while running- NO CHANGE, so I assumed the wires were ok.

Coil I will raise it up like you say and try that.

02 Sensors- when I have exhaust off I took out (2) of the (3) I could not get one out- cleaned the 2 and put back in with small amt. of anti-sieze incase I had to replace - my luck it will be the one I could not get out -LOL, but at least the bad sensor should not run this bad? so I can put that on bottom of list. right?

DPFE- I did see some info. on that- very expensive- so when I was at salvage yard on sat- I got (1) that is identical and a plastic one off of trucks in the yard- (I KNOW THEY COULD BE JUNK TOO - BUT I WANTED TO COMPARE- THEY COST ME PENNIES TO TRY) I also pickup another IAC sensor too to try.
My plan is to do one at a time and see if makes dif. if not then write on it known good part and put in my drawer for next truck. Who knows I may get lucky...

Seriously- thanks for helping me...

 

Sensors cannot be cleaned, if you went throughout he trouble of removing, I'm surprised you would put them back in, they are maintenance items and should be replaced before they fail. They can fail long before you every get any codes.

A sensor would not make it run that bad, BUT, you have a code that says its bad, replace it, it belongs on the top of the list if you have a code telling you its faulty. Replace the one on the other side too, it has just as many miles on it, and even if its not setting code, that doesn't mean that its working any better.

The DPFE is not an expensive part, especially when it is an easy DIY replacement. Just buy a new Motorcraft one. The changes of getting a good one out of a yard is pretty poor, and a wrecking yard is not supposed to sell those, they are emissions components, its not legal to sell used emission components without first testing them to confirm they are good.

I would put a vacuum leak very high on your suspect list. You many not even be able to hear the leak, but it throws the computer off, especially at low RPM.

 

Here is a link to a pictorial of the 3.0L & 4.0L coilpack terminal & spark plug numbering layout that Rockledge posted. The black arrows are pointing to the front of the truck where we would stand when we look at the engine from in front of the radiator.
Ford Truck Enthusiasts Forums - View Single Post - 2000 Ranger 4.0L Misfire

So cyl bank one is passenger side & the front engine cyl is #1-2-3, drivers side is cyl bank-2, the front is cyl #4-5-6

Note that the 4.0L has a waste spark ignition system, so the coil pack cyls are paired together such that when #1 cyl fires on its power stroke, #5 cyl its coil pack partner, is being fired on its exhaust stroke (waste spark), same for cyls 2 & 6, cyls 3 & 4.
So as we look at the coil pack from the front, plug wire 1 & 5, 2 & 6, 3 & 4 are paired together on the coil pack, so make sure the plug wires are routed right from the coilpack to each cyl & that there is no breakdown on the wet down test of each wire. Also make sure each wire has the specified end to end resistance & its a steady reading when the wire is flexed.

The MAF sensor is to only see filtered air, so if it was dirty you need to look up stream to find out why!!!! Typical problems are over oiled foam or cotton gause air filters, improperly buttoned up air box, damaged air filter, air box, air tube, or modified air intake.

O2 sensors can't be cleaned with a spray product & if sprayed with the wrong product, say with one that has silicone in it, that'll kill them.

If the DPFE sensor is kaput, it'll cause the EGR valve to misbehave & that sure won't cause the engine to run better, so best to get that puppy fixed pronto. The EGR should Not be open when the engine is cold, or when its at idle.

Good that you used MAF sensor spray cleaner, but I hope you were really careful & persnickety, cleaning the MAF sensor with a cotton swab & didn't touch the sensor wire & if you did touch or clean it, didn't damage or leave any cleaning residue, or cotton fibers on the sensor wire, as that can uncalibrate it & cause the computer to mess up the air/fuel ratio.

I wouldn't run it too much with it misfiring, as thats hard on the cat converters.

Let us know how your trouble shoot goes.

 

Thanks All-
A few comments to add...

When I cleaned the MAF I made sure no cotton left and was very careful to clean, as with the other sensors I was talking about (meaning the IAC, and the one that goes in the air intake tube)- the 02 sensor I know was a long shot- and your tight I need to replace both but kills me at 65.00 each I am trying to keep costs down- dont get me wrong if it needs to be replaced I will do it. A family of 5 and kids in HS money is tight- so you can see why I am trying my best.
Emission parts I picked up at yard- (I know they could be bad to begiin with) Last nite I tried 2 more DPFE sensors- made no difference- I tried another IAC-I thought for a moment it was little better, but I dont think so.
I checked all plug wire locations and were where they should be- I raised the Coil up
1/8" using rubber and no difference.
I just read another post that a guy put new plugs & wires in, and found out his miss was the wires and or plugs he replaced again and it was fixed?
I think I need to do a check of each wire or break down and just buy a set- Again I have no problem buying them just dont want to throw $$ away.

REFRESH- the problem is she seems to miss when idle a tiny bit- but in gear sputters quite bad. Truck starts very easily and will idle all day long.

PAWPAW- I printed a 40 item post you talked to someone else before on- and gave them a ton of info- so I am using that for reference in this repair.
I think I need to find (2) 02 sensors now- I will look online- does anyone have an opion on the ones from like 1A or RockAuto I may be able to get cheaper..

thanks a million to all

 

You may have more than one problem causing the sputtering at throttle up. So test, confirm, then replace the troubled part, don't just throw a part at the problem based on a huntch.

For instance there are a number of components to the EGR system, including the DPFE sensor, a computer controlled vacuum switching valve & vacuum lines between the DPFE sensor, EGR valve, vacuum switching valve & a sensing orifice below the EGR valve & hose to it, that likes to get clogged with carbon, which will cause mischief, so the the DPFE low input trouble code could be caused by something else, thus the entire EGR system should be on your suspect list & each part needs to be inspected & eliminated as a suspect,Then replace the problem part. Vacuum line leaks & carbon clogs of the feedback port below the EGR valve & carbon clogging of that connecting line are common problem areas, along with DPFE sensor problems. The EGR valve itself is robust & rarely a problem, unless its rusted & falling apart.

For instance, if you have a vacuum leak in the computer controlled vacuum switching valve diaphragm, or connecting vacuum line that controls the EGR valve & because that air leak into the engine isn't monitored by the MAF sensor, it could cause the engine air/fuel ratio to be corrupted & go lean & cause throttle up problems.

Electrical contact problems at the DPFE sensor can corrupt its output to the computer & mess with what the computer has the EGR vacuum switching valve do with applying EGR feedback into the engine & if it comes at the wrong time, like at throttle up, that could cause engine sputter, Its all a vicious circle, so don't get frustrated & jump to a conclusion & throw parts at the problem, take your time, think things through, get positive trouble shooting results, Then replace the troubled part.

Good trouble shooting feedback on raising the coilpack to eliminate an underneath external electrical breakdown problem to ground. I'd still do a wetdown test on the coilpack & plug wires after dark & look for arcs & sparks, or rougher idle.

However if no joy with the wetdown test, the coilpack could still have unseen internal electrical insulation break down/leakage problems, that could cause a weak spark that could blow out at throttle up, so consider doing a primary & secondary coil resistance check & if that ok, removing & taking it to an autoparts store for a no cost electrical output bench test. The coilpack primary resistance isn't speced by Ford, but is typically an ohm or less & the sedondary resistance is 13K-15K ohms.

The plug wires typically measure 1K ohm/inch of length, 30K ohms max, no matter the length & the resistance should hold steady as both end connectors are flexed.

O2, MAF, TPS & AIT sensor or electrical feeds to or from them, or fuel pressure drop from a weak pump, or faulty pressure regulator, can affect fuel trim & cause stumble or sputtering at throttle up, so right now you only have the bank-1 upstream before cat O2 sensor heater & DPFE sensor trouble code clues to work with & it seems to me if the engine is sputtering at throttle up, there should be more trouble codes stored in the computer & if so, they sure could provide more trouble shooting clues.

Short & long term fuel trim numbers & fuel pressure, would be helpful to know, if you run into a dead end on the spark trouble shooting.

Keep us posted on your trouble shooting results & sooner or later you'll likely get a positive test result that should provide a good clue to whats going on.
If you have any other trouble code Numbers, be sure to post them.

 

How do you test this type of coil pack?
I have done the old style before but never this pack type.

I will try to test tonight.
thanks

 

To test the coilpacks 3 secondary windings resistance, remove each companion plug wire on opposite sides of the coilpack & do a resistance check with your multimeter on the x1000 ohms scale & measure across each of the three secondary coils. As posted above they should measure 13K-15K ohms.

To test the primary resistance, you'll have to remove the coilpacks electrical connector & probe the coilpacks primary contacts & while your there, you may as well check B+ to the coilpacks electrical connector at KOEO, to make sure there isn't a B+ voltage drop to the coilpack, as that too could cause a weak spark that would blow out under load when you go at throttle up.

 

Thanks I have printed the steps and will try to do this tonight.

 

Hey I just started to have what sounds like the same problem with my 98 ranger 4.0, but first what is MAF, IAC, PCV, EGR, DPFE, and Coilpack and where are they. I don't have a computer thingy to find the code, but the check engine light comes on and off.

 

MAF=Mass air flow
IAC=Intake Air control?
EGR=Exhaust Gas recirculation
DPFE= Diff. Pressure feedback EGR?
PCV=Positive Crankcase Ventilation


I think those are correct...

PAWPAW-
Last nite I checked between posts got 12.8,12.6.12.8 sis this with OHM meter.

Was not certian on the elec. plug testing put probe on end spade of 4 and probed they aall were .001 or very low - I think I had it on a high setting. this was on the coil not the wire/jack.

Also I took off coil cleaned rust from bottom and the plate it sets on.

sorry to ask- but is there a diagram of list on what you meant by checking the b+? I dont know what tihs is, and with KOEO should I tet the jack and how and with volts?
Thanks

 

OK, good feedback. Looks like the coilpack primary & secondary resistance measurements are ok. However it could still have internal high voltage break down & a bench check should be able to find that.

B+ = Battery +, or +12 volts, at the coilpacks electrical connector.

When we go to Run on the ignition switch, B+ is supplied to the computer by a power relay & the computer supplies B+ to the coilpack & the fuel pump for a couple of seconds to build fuel pressure & prime the system in preperation for the start. Then when we crank the engine to start it, the computer ground switches the proper coil to make spark on the correct pair of plug wires, depending on the timing signal it gets from the crank sensor & it fires the fuel injectors in time from a signal sent by the camshaft sensor.

When the computer gets crank & cam sensor input to tell it that the engine is turning, it looks for indication that we have oil pressure & if so, it'll turn the fuel pump back on so the engine will continue to run.

SO, lots of things are happening on a start & we need to make sure the basics are in place, like good battery voltage to all parts of the electrical system & this includes good ground connections between the battery B- post & the engine & body.

To get a healthy spark, we need the battery to supply the computer B+ without voltage drop & the computer to apply full B+ voltage to the coilpacks electrical connector. So the battery needs a good charge & be able to supply up to spec under load voltage output. Its electrical connections & battery cables need to be clean, bright & tight. No post or cable corossion, broken wire strands. The electrical feed to the under hood fuse/power distribution box & its internal electrical connections to the power relays & fuses need to be in good condition. If they are, you should not have any voltage drop to the computer, coilpack, or fuel pump, at KOEO.

 

Thanks alot- I wll test tonight and post results-

Again- thanks for hainging in there with me- I have more time then money so testing I will do.

I will eventually post the fix- there have been many forums that people will not follow up and give final results..

 

Update-
the DPFE I got at salvage yard seems to be better then the one I had- the code is gone (P1400).
She still has issues tho- Last night I ran in park - held pedal at about 2K and she seems to want to stall then perk up over and over- so Maybe has nothing to do with trans or TC.
I am off for 2 days and will tonight do a DARK wet Test look for arcing- will check to see if I can get coil pack tested at AutoZone and do that- have to check each plug wire yet.

Thanks..