thank for all advice

I will check plugs , wires and coil again !

Whoaa . thats heavy ( the solenoid not working properly )
Yea i guess its a possibility ... ill try to swap in the working spare imrc valve solenoid...

as far as i can tell all wires and connectors looked pretty good-
no burnt harness spots , wire to imrc stuff look good, no other codes popping up

I further looked up coil pack issue with the ranger and they had some similar issues and symptoms......
On ebay oil pack go for about 30 bucks , about 60 at autozone i think

Honestly, now that the imrc valve didnt fix anything , I feel super stumped.. guess just need to thro parrt at it ...
It barely runs right when it used to run great .... its freakin frustrating

im almost considering bringing to the ford dealership for diagnoses

I give the other imrc valve a try and then check the coil further, maybe try a new one ..etc....

Just curios, did you try a new coil pack or test it? I've heard that at lower RPM's a bad coil pack will exhibit this issue. I have it happen to mine all the time and I'm sick of it, so I ordered a $34 coil from amazon tonight and once it comes in I'll be putting it in. Mine idles pretty well and revs fine like yours does. It's worth a shot, or at least testing yours before buying a new one.

__________________
95 Ranger Xlt Supercab 2x4 Auto 4.0 128k
99 Jeep Cherokee Sport 4x4 Auto 4.0 153k

You should check the bushing that the runner sits in behind the power steering pump. It is common for those to blow out and now you have a vacuum nightmare. Also, i currently have my runner disabled and i experience similar chugging. I think it needs that runner to work in order for it to run properly.

__________________

Welll I kinda fixed it




So as stated in the original post, my 2003 ford ranger always ran pretty good. But then a few months ago it got the chuggs.
It was really somewhat an instant problem- all of a sudden it got the chugggs at low rpms .....

lots of hesitation, chugging, surging only at low rpm, under load. With really smooth light throttle the chuggs could be somewhat avoided but with regular throttle the truck would chugg, hesitate and bounce its way to 2500-3000 rpms and then it would run smooth ( smoother)


When this happened I checked some codes, searched for possible issues and came across the imrc stuck open code amongst others ......


So back then, I checked into it and did find a broken vacuum hose, at the bottom of the imrc solenaid valve switch .... so I snipped and reattached that. there was No change in the chuggs.
I decidedd to check other possible problems ....
I replaced the plugs, put in the autolite cheapos, I replaced the fuel filter , I cleaned the maf, throttle body and the IAC. there was an o2 sensor code so I replaced that also...



None of this changed the problematic Chuggs


my ranger had the chuggs and they wouldnt go away


So I investigated the imrc even more and tried to bypass the " faulty switch". Well that didnt help either.

I got sick of this imrc in the intake and not being able to see or test it , so I removed the intake. took the intake off , cleaned and tested it, but couldnt find any problems whatsoever

I cleaned the actuator and flapper. I pressure tested the actuator , and found it appeared to work just fine



after chuggin around for months and getting misfire codes and IMRC stuck codes, I thought I would have to go buy a 120$ imrc solenoid switch.
but I had both of the codes so I dint know whether or not to get the switch or the coil ....

I checked the vacuum lines and tested vacuum with a guage .etc etc .....

Appeared something funny happens with throttle, and that imrc solenoid switch ... thought it wasnt working for sure ...

So ...
Ended up going to junk yard for a couple of switches ( imrc vacuum solenoid switches) . tested all the switches with the newly acquired wire connectors/ switches.

Found my original ford one working !!!! ---- this could be because of the direct voltage or that I cleaned the solenoid with electrical cleaner while it was off also ...

SO I slapped it back on there ... made sure all the vac lines were good and test drove --- very little change if any , except that the only codes popping up were Misfire codes ...
p0302,p0300;p0304


So then I went and tried new plugs,Installed autolite iridiums, cleaned the wires and terminals , and reconnected everything


FIXED !!!!!!


Well prettyy much

after a few days of driving, I have gotten zero( 0 !!!!) fault codes and it runs pretty much normal !!!! I am super stoked


BUT

I still have some very slight chuggs .......
I would call it 90% fixed and running well......

But it seems under load and very low rpm , it chuggs a bit.

Some very minor chugg still present

it appears to come and go a tiny bit, with smooth throttle it wont chugg at all and accelerate NIcely ! , but at very low rpm and a lot of load , i feel a tiny bit of chugg

Its pretty wierd that it has almost 100 % dissappered but still remains a bit .

I feel like it is probly a bad vacuum line or similar ... I plan to replace vacuum line with better quality ones atand see how it does
If all vacuum lines are good then I am gonna replace the coil

i am very happy to have the truck running fairly well again

* notes*
--when I checked vacuum it would hold vacuum suction pretty well , I checked numerous ways with a gauge ( also the pressure between the IMRC valve and actuator)--- then there would even be vacuum remaining when the truck was off
( I would pull a vac line and here the suction pressure release)


-- my plugs and wires had a little corrosion, probably poor connection, the new Iridium plugs have much different electrodes- possibly allowing easier spark from the coil --- Maybe the coil has been weak and needs replacement , I will prob try that next and replace it as maintenance.