Fuel Injection problem

[RANGERBRAZIL]

Hello, I have a problem in my 4.0 Ranger 1996!
The ever lower rpm of 1700-1400RPM and also oscillates!
Here in Brazil there is not much what to do ...
I'm trying to solve this problem by eliminating!
Changed TPS, IAC ... and even throttle body ... the problem following!
What is the next step?
Someone went through it? What it did was done ?!
Thanks, and sorry my terrible English!

 

[RonD]

Throttle plate or throttle spring

remove cruise control cable from throttle to see if that is effecting it

Check fuel pressure at steady 2,000rpm

Check vacuum pressure at idle, at, 1,000, at 2,000 steady

 

[RANGERBRAZIL]

Throttle plate or throttle spring

remove cruise control cable from throttle to see if that is effecting it

Check fuel pressure at steady 2,000rpm

Check vacuum pressure at idle, at, 1,000, at 2,000 steady

Cruise control 100% ok... cable trottle body is ok... fuel pressure is very good!
I believe that should be any sensor!
which symptoms spoiled maf sensor? which symptoms camshaft sensor? crankshaft sensor which symptoms?
Once agaim... excuse me for the wrong words! My English is very bad!

 

[TxGasRacer]

http://troubleshootmyvehicle.com/ford/4.0L/index-of-articles-1

 

[RonD]

No sensor problem will cause RPMs to go up and down(oscillate)
IAC Valve is a "control" not a sensor, and it could be opening and closing so try unplugging it and then driving if RPMs still go up and down then IAC valve is OK

Crank sensor problem = no start, and CEL(check engine light)
Cam sensor problem = lower MPG and CEL

MAF sensor problem = stumbling, hesitation and CEL for Lean condition
O2 sensor problem = false report of Lean or Rich fuel mix and CEL

Try removing and plugging 1 vacuum hose port on the intake, and see if RPMs get stable again
Repeat for all vacuum hoses.