94 Ranger 4.0l engine turning off

[MatthewGraham]

When slowing down to a stop light, stop sign, or to enter a turn, my engine's RPM plummits and hits 0 causing the engine to stall and cut off. I have no clue what could even possibly be the cause, so if any experienced people could kindly thing of a list of things I should check, I would be very appreciative of them.

The engine type is a 4.0L V6 2WD. Also, in case it might be the cause, I leave my MAF sensor unplugged because when it's plugged in I get 10MPG. When it's unplugged I get 20MPG.

Thank you for taking time to read this, and thanks for any advice, suggestions, and/or comments you leave.

 

[straycat]

Fuel pump, fuel filter etc........when did you last service the 94??

 

[robertc1024]

What kind of tranny do you have?

 

[MatthewGraham]

I'm not sure when the last time was.
It's a manual trasmission. 5speed

 

[CHKNFKR]

I hate to even have to ask, but are you trying to stop while still in gear with the clutch engaged?

Sent from my SAMSUNG-SGH-I997 using Tapatalk 2

 

[MatthewGraham]

Haha no. I throw it in neutral, let off the clutch, and then start braking.

 

[CHKNFKR]

and at what point does it stall?

 

[MatthewGraham]

Usually a few seconds after it's put into neutral.

 

[adsm08]

The IAC is a likely suspect. I would also invest in a new MAF if running with it unplugged doubles your fuel economy. No way that sucker is working right.

 

[4.0B2]

The IAC is a likely suspect. I would also invest in a new MAF if running with it unplugged doubles your fuel economy. No way that sucker is working right.

this. IAC was my first thought...

however, IF you have to leave your MAF unplugged b/c of any reason, something is wrong! ford ain't idiots, they didn't put that there to cut your MPG's in half... i'd replace it, or figure out the issue there.

maybe i should try unplugging mine

 

[MatthewGraham]

The IAC is the idle air control right?

And the MAF sensor actually was replaced a few weeks ago, but there was no change other than the jumpiness and hesitation of the truck had gone away.

 

[MatthewGraham]

I just called my step dad and he said the IAC was replaced with a new one.

 

[adsm08]

IAC is Idle Air Control, yes.

If you have replaced the MAF and it's still doing it reset your memory by unhooking the battery over night. If that doesn't help look into the wiring.

 

[4.0B2]

your ECU could even be bad... hate to be the guy to say it, but i've seen it happen.

i'd check wires... ain't there a way to test the wires coming to the MAF? w/ a ohms meter or volt meter or something???

 

[MatthewGraham]

I already reset the memory before, and it didn't get rid of the issue. The wiring was a thought I had too, I sprayed the connecter with electrical cleaner, and that seemed to help the idle issue it used to have.
I don't know where to get new cables though.

Also, do you know what the normal RPM at idle is?