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.