WATCH MY TRUCK PROBLEM --------> https://www.youtube.com/watch?v=vo0X...ature=youtu.be
1994 FORD RANGER XLT 4.0 V6 4x4
WHAT I CHANGED - So I have changed sparkplugs/wires, alternator, MAF, fuel filter, intake gaskets, o2 sensors, idle air control, pcv valve, and master slave. I just found a exhaust leak right up on the point the exhaust attaches to the engine, on the muffler, and on 1 of the cats and have tried other battery.

PROBLEM - So my problem is that when I start the truck im set at around 400-600 RPM at idle the truck trys to die the battery flickers when I try to drive the truck has hesitation and jumps on the road and when I push clutch in then release the trucks battery flickers and the truck drops rpms trying to die and sometimes does die even when driving. exhaust at one point put out a lot of smoke and spewed lots of black carbon on the road as a powder I dont know what to do I am currently adding Exhaust Putty to the exhaust leaks to see if that will fix it in any way at all but have low hopes please help. when plugging MAF wire back into MAF sensor the truck just dies or goes back to sounding like WOUHHHH wou WOUHHHH wou WOUHHHH wou WOUHHHH

Solution? - the only solution I have found was to unplug the MAF wire and the truck jumps to 1000rpm and runs amazing Ive tried two brand new MAF sensors and have Back tapped all three i have and hooked a tester to them to see if any current or problems. I cant figure this out I have put so many brand new parts in it and nothing.

 

Duplicate post
https://www.ranger-forums.com/4-0l-o...7/#post2161359

 

I have duplicated it because i just cant get a solution

 

Multiple posts don't help

If you start engine cold and idle is low, under 900rpm then your ECT(engine coolant temp) sensor should be changed, it can be tested but cheap to change
ECT sensor has TWO wires
Dash board temp SENDER has 1 wire, they are not interchangeable
Both are near the thermostat housing

All gasoline engines need to be Choked on Cold start, the computer does this when ECT sensor shows coolant temp under 140degF
Choke mode is high idle, usually 1,100 at first, and a Rich fuel mix, any gasoline engine will stumble and stall unless it is Choked when cold

The computer uses the IAC Valve to set high or low idle RPMs, you need to use Motorcraft IAC Valves, 3rd party will give you grief, a used Motorcraft IAC Valve from a wrecking yard is better than a new 3rd party IAC Valve
You can clean IAC Valves, seen here: https://www.explorerforum.com/forums...-w-pics.84220/

You can remove IAC Valve and plug in its 2 wire connector, turn key ON
Now watch the valve open and close when you unplug and plug back in its wires, only moves 3/8" but should move

An alternator doesn't have full output until engine is at or above 1,800rpm
So at idle 650rpm the battery light might flicker if you have 1 bad field in the alternator
An alternator has 3 fields that generate voltage, not uncommon for 1 of these fields to stop working when alternator gets older, it would show up as dimming head lights at idle or flickering battery light at idle.
Only fix is to replace alternator

Exhaust leaks wouldn't cause your issues but will cause lower MPG so costs you $$

Unplugging MAF sensor puts computer into "safe" mode so it would raise RPMs and run the engine Rich, it would also ignore other sensors in this mode
This doesn't really test anything, it can "get you home" but doesn't point to any specific issues

 

Thank you very much sorry for being childish and putting up a ton of post I will go and delete them if i can or erase the text itself, I will definitly go check out all of this and do as you said the Alternator is brand new but maybe they gave me a bad one so I can take that back and replace it with another new one if I can find the recipe in the hugh pile of recipes I have for this car LOL. I just noticed that the coolant is almost non existent in the resivor so im going to top it off also but thank you for the information and sorry again about the multiple post just wanted to try and get to as many people as possible

 

VIDEO OF PROBLEM
https://www.youtube.com/watch?v=Ydaj...ature=youtu.be
PROBLEM
So I have currently changed SparkPlugs, Sparkplug Wires, Alternator, MAF, Fuel Filter, Intake Gaskets, O2 Sensors, Idle Air Control, PCV Valve, Master Slave Cylender, and after getting advice from @RonD I changed the ECT SENSOR with no luck, Just maxed out the Radiator Coolant because the truck was very low it seems like nothing fixes the problems with this truck. Please if you have any insight on a way to solve this issue please do help I have given a video of the problem and the truck driving please watch through to understand and hear the problems with my truck thank you!!!

 

You should just post in the same thread you started

Its wrong, only watched 50 seconds of video

Should REV to above 1,000, closer to 1,500RPM on startup, without touching the gas pedal, ALL fuel injected engine will do this, cold or warm, not a Ford thing
Then should stay at 1,000rpm or so IF engine is cold

So either IAC Valve is not working or Computer is not working, only two choices at that point

Remove IAC Valve, plug it in to its wires, turn key on

IAC Valve should be OPEN all the way, key on engine off, ALWAYS, thats for start up and why it should REV above 1,000rpm
Unplug its wires, you should see valve close, only moves 3/8" but should move
Plug wires back in so it OPENS all the way again
Repeat until you are satisfied it is or isn't working

You can test voltage at the IAC Valve wires, Red wire will show 12volts with key on, computer controls the ground wire, it modulates the ground to close the valve
So volt meter connected to BOTH wires should show 11-12 volts key on engine off
If not then computer is the problem

Test red wire to engine ground, should show 12volts, if not red wire is broken, MAF red wire uses the same 12volts, as do EVAP and EGR solenoids
You can hook IAC Valve to 12v and ground and it should open, there is no polarity, its a solenoid


If IAC Valve "looks" OK, but its Ground wire doesn't test OK

Then pull out computer, its in the drivers side engine bay down below Clutch reservoir
Between firewall and inner fender
Open it up

Should look like this inside: http://www.auto-diagnostics.info/ford_eec_iv

See the 3 blue capacitors
Well those can leak after 20+ years and cause all sorts of running issues
$5 fix if you solder

Steps are here: http://support.moates.net/capacitor-...-ford-a9l-ecm/

 

Best advice I can give right now is, stick with one thread for this issue. Starting so many threads for this same problem is going to turn people away from trying to help you.

RonD beat me by a minute.

 

Robert (PinkGapple),

If you haven't noticed, your threads have been disappearing, and I am the reason why. I have removed all of your duplicate threads and merged your new thread with the one from yesterday. I am asking you to please stop creating a new thread each time you have something to say. Please continue to reply to this thread concerning your engine problems.

Thanks.

 

Sorry didnt think about it

 

I appologize didnt realize posting in the same thread people would see this is first forum i have ever joined, thank you for merging them and sorry about that

 

Thank you very much and sorry for the multiple thread thing, I realize now thats a problem this is my first forum i've ever joined. I just bought a brand new coil pack and threw that in then came home and seen your post I will definitely do these steps tomorrow to see if it is the computer i have a brand new Idle air control in the truck basically everything is brand new at this point has been a month of money dumping and only other thing at this point i guess would be the computer or one of the parts I put in that is brand new has an issue but with your help the solution should be found tomorrow then thank you very much this is my first vehicle ever and have learned a ton on this journey to fixing an over priced truck that I was lied to about, but thats ok once this problem is fixed ill basically not have any major problems for a long time because everything has been changed

Thanks - Robert

 

No worries. Let us know how the Idle Air Control valve testing goes.

 

And remember

NEW no longer means "it works", that was 20+ years ago, in a galaxy far far away now

There have been many and frequent posts on ALL automotive forums that "new" just mean NEVER TESTED

So test any new part as best you can

One of the problems you have now is that there are TOO MANY new parts on your engine, so some WILL BE defective, for sure, 100%

So we can just deal with the symptoms as they present themselves
First being low idle on start up and no REV on start up

Do not touch gas pedal on startup, just crank, any fuel injected engine should start and REV above 1,000, then settle down at 1,000 if cold

 

just took out the computer and two of the solenoids look like this https://www.youtube.com/watch?v=d-oE...ature=youtu.be