Hey i have a 1996 Ranger 2.3L it has been running rough and is underpowerd so i unplugged injector 1 while it was idling and it nearly killed it but when i unplugged injector 4 it continued running the same, so i swapped the 1st and 4th injectors and still had exactly the same problem, then i ran a scan and got the misfire on cyl 4 code. Any ideas what sensor could be bad or is it a short somewhere?

 

Are you sure you have spark on cyl 4
I'd also do a compression test on all 4 cyls, maybe 4 has low compression.

 

i am going to double check but im sure i have spark

 

Welcome to the forum


Fuel injectors all get 12volts with key on, the Red wire at all 4 injectors, same for pretty much all fuel injected engines

The computer Grounds an injector to open it

You can get NOID lights, because the ground to the injector is so fast a volt meter or even a test light won't see it pulsing
NOID light was designed to test if a fuel injector is getting the ground pulse from the computer while engine is cranking or running

But there is a simpler test
Spark plug tips
Cold engine
Disable the 2 coil packs, unplug the 3 wire connector on each coil pack
Crank engine over 2 or 3 times
Pull out either spark plug in #4 and any other spark plug that's easy to get at
Compare the tips, BOTH should be WET with fuel, if so injector is working
If #4 is dry then yes no injector pulse from computer which means you need a new computer, so you want to make sure on this.

The 2.3l Lima engine could have rocker issues, which would show up as lower compression, rocker could slide to the side and not open valves far enough
So when you pull out #4 spark plug have a compression gauge handy to test it
2.3l Lima should be at 160+ psi, but check at least TWO cylinders, all 4 would be best but at least two need to be test to make any kind of judgement

 

Thanks for the answers, ill check that all out and get back to you!!

 

And a quick update yes i do have spark to both plugs

 

I checked the spark plugs and i am definitely getting fuel i checked the compression and im getting about 15psi on all cyl, the truck has 263,000 miles and still has original timing belt so i was wondering if the timing belt was slack could the exhaust valve be opening and letting the compression out? just a thought. also it is not holding compression it just jumps up to 15psi with every revolution of the engine

 

1996 2.3l Lima engine should be at 160psi compression

No engine can start with less that 100psi

So your cam/crank timing is not correct

There are diamonds and triangles used on BOTH the Cam and AUX gears, these are the same gears and interchangeable
The diamonds can get worn and look like triangles

Look at this diagram: https://www.2carpros.com/images/ques...1/original.jpg

It shows the diamond on the Cam gear at the TOP, the triangle is at 4:00 position lined up with Cam timing mark

AUX gear(oil pump) has diamond at the TOP lined up with its timing mark and the triangle at the 4:00 position

The crank gear Key way is at "approx" 12:00 it should be 90deg to engines oil pan, so key way will be closer to 11:30 since engine sits at an angle

For compression to be that low the Cam gear is not timed correctly, it sets compression, so it is probably set with diamond at 4:00 instead of 12:00, that would put the triangle at about 9:00, so your 5 "hours" off, lol.


Useless knowledge part
Compression is needed because liquid gasoline can't be ignited by a spark, yes the Movie Guys take liberties with that part, lol
Compression causes HEAT
And when you heat gasoline some of it changes to a Vapor, and gasoline Vapor can be ignited with a spark
You need minimum of 30% Vapor in a cylinder to get full ignition
In cold temps the gasoline has less vapor, i.e. doesn't "smell" as much as when outside temps are warmer, that's the vapor you smell

To get enough heat to vaporize enough gasoline you need compression above 100psi, in warmer temps, in colder weather 120psi

A Block heater is used to keep engine warm enough in cold weather so gasoline can be vaporized easier
Ether is used to start cold engines because it has a lower Vapor point than gasoline
So its all about Vaporizing the gasoline to get to that 30% minimum for start up
Once engine is started the cylinders heat up fast so gasoline is vaporize easily