Very rough running

[88AMCOMANCHE]

Last nite I attempted turning the tiny screw just to bring my idle up a tiny bit,but the screw wouldnt move,so I stopped because it idles about 5-600 rpm. Just wanted it apinch higher. - This morning I headed out to go to work,when out of nowhere,the truck started missing & running rougher & rougher to a point I had to find an immediete side street. Pulled in the grass & kept revving it,trying to keep it running. ....Seems like over 2500 rpm it smooths out a bit. SO.....I struggled for 2 miles all the way back home, doing anywhere from 5mph to 15mph , as traffic backed up behind me.
Made it to my driveway. Now, it wont Idle. it will start , but quikly sits at about 300 rpm running rough till it dies. ....I had to call in for work. Can anyone Please give me some pointers., This seemed to happen out of nowhere. I looked & dont see any vaccuum lines off anywhere nor does anything appear to be unplugged. Bad part is,.,.I have No way of getting to a parts store even if I could find out what the problem is, when aa vehicle goes down,its like life stops kinda.Cant go buy food or smokes or anything at all. ANy pointers what to look for?? I ve heard if you unplug the Idle control sensor or throttle positioning sensor,it resets it & works again? as weird as that may sound. Maybe one of them have went bad. I have no idea!! Help? anyoine. I'll take any pointers,cuz im beyond lost right now. sorry so long here.

[default83]

I would guess vacuum leak.

double check it.

[xj4life2]

Based upon my experiance with my Jeep and words of knowledge form my highly trained mechanics ..... Anyway sounds like you have two issues first the iac motor is done , I would try to remove it and clean it. If that doesnt work then you'll need to replace it. Next along with that it sounds like the 02 sensor has gone bad also, just replace it especially if you have over 20k miles on it. A vacume leak on these normally cause a increased RPM. When mine did the same thing thats how I got home, I created a vac leak to raise the rpm , didn't fix the miss but did get me home.
here's a link for ya on how to check sensors and what they each do :
http://www.lunghd.com/Tech_Articles/Engine/Basic_Sensors_Diagnostics.htm

[steph74]

yes it is really possible that when you tried to adjust the tiny screw, you moved/knocked those sensors on the throttle body.
IAC (iddle stepper motor or Idle air controller) is definitely something you should check like Mark recommend.... I hope for you it is not that though they get pricey ;)
It is my understanding that you need a special tool to test it.

Your Throttle Position Sensor is easy to test but I don;t think that it could be your problem.

NOW.... check your MAP sensor vacuum line that connects to the throttle body. When I knocked mine, I had some of your symptoms. car would run rough and not hold the idle.... I could keep it idling a bit with giving it gas.
this line is straight from the MAP sensor to the TB and should be connected to the bottom hole IIRC

[88AMCOMANCHE]

hmm no idea wher or what an 02 sensor is,but will see what i can find on that. To finetune my description of teh symptoms its having .....You have to manually work the gas pedal to keep it running ...and it sounds as if youve pulled a plug wire loose like its running on 5 cylenders or something. Anything under like 2000 rpm it will surely die. But by continually working the pedal or by hand, you can keep it running atleast. which sucks.
ty for the info. I bookmarked it!

[steph74]

you should have only 1 O2 Sensor. it is plugged in the descending exhaust on the manifold part. it is a tube that sticks out perpendicular, hard to miss if you look under the truck. and is measuring the oxygen content of the exhaust gas to adjust the fuel injection system (please correct me if wrong)

On that page there, they tell you how to test it...

[88AMCOMANCHE]

I am trying to get the hang of the sensor abbreviations & all that stuff. I have no idea what an IIRC is , i will check that sensor site & see if I can find that on there. As far as a vaccuum line...I will just go out there & look around again for any line or anything. But since u mentioned the vaccuum lines again. Ty. - This is my 2nd breakdown within 3 weeks. Very frusteratiung. Going now to checkout vaccuum lines.

[88AMCOMANCHE]

I think he mentions that ..That sensor gets damaged often especially during engine swaps or exhaust swaps. And even if it looks ok it could be bad. I THINK.
My problem is...Im STUCK at my house until I figure why it wont idle hardly. It misses badly to where ya cant gain any real speed otherwise id drive to a mechanic. You & anyone who answers are being helpful,cuz when looking for info, its liek a never ending thing.And im quite green stiff. Cuz Jeeps are theyre own beast so to speak. bbl,gonna go stare under my hood !!

[steph74]

IIRC is not a sensor so you are good, it just means If I Remember Correctly

[88AMCOMANCHE]

o0ps .....Ok, Gotcha lol thanx. Also- Ive just went over the entire engine compartment top & bottom and theres no loose vaccuum lines or anything unhooked. But just now I remmber....about 3-4 times now ...When I started it up, it would idle super high and not come back down until I shut it off and restart it. 2 days ago I just drove it home with the idle about2800 rpm. Had to just run in 3rd gear all the way down my street otherwise id start speeding. / Next time I start it it starts normal (around 600 rpm) In the last year its never acted this way,up until the last week or so . Its done the high idle at startup about 3-4 times within a week. / maybe its a sensor thats going bad,maybe? gawd this is stressful. If I knew where this sensor was everyone keeps mentioning (ICS? ,TPS? ) or something like that,Id try removing it (2 torx bolts maybe) and lightly clean it, out of sheer desperation. aNything at this point.

[88AMCOMANCHE]

there was a small skinny vaccuum line,but its hooked up on both ends and connects where u said .

[steph74]

then your IAC is gone.....
(but that is the easy answer.... it can be a bunch of other things too)

Remember that if you pull the TPS, or move it, you will have to readjust it too it is super easy to do.

When is the last time you cleaned the throttle body ? you may want to check that it is clean enough as well and that the buttefly (i am not sure about the name) closes properly....

[88AMCOMANCHE]

For a year Ive drivin around my yard about once a week,sometimes once every 2 weeks just to keep the battery up & keep it from sitting. As far as cleaning that stuff, Nuthings been cleaned because its always fired right up & ran great. Till Now. So if i mark on each side of the tps thing ,like mark a straight line across,so when I put it back on Its lined up. Would that be ok, or would i still have to reset or adjust something? Guess i need some carb cleaner. But its about 4 miles away that walmart. Im kinda stuck and cant drive to get it.but as soon as I can I will pickup a can.

[steph74]

it is 3 torx screww to remove the airtube and look inside the throttle body... quick and free check Pull the throttle cable and let it go down while you look at it and see if the plate is moving freely and closing good.

I am not sure about marking the sensor and put it back that way.... it is a really fine tuned adjustment and 1 tap in one direction will be sufficient to move the voltmeter.

when you get the chance, if you have not done already, i would get a good DIGITAL multimeter.... some are cheap and I would stay away from these. I think I got mine from Wally and it is OK.... this is the essential tool for your renix engine I am afraid...

[88AMCOMANCHE]

I removed the TPS and theres nothing at all to clean. I wasnt about to remove the spring loaded screw to get further into it. so I put it back on & now trying to adjust it so it will start atleast. / Thought people say to remove that and clean it? maybe its something else that gets buildup & dirty maybe.

[steph74]

yes it is the IAC... should be the one on the left

[88AMCOMANCHE]

just finally adjusted it to where it starts up .....seem to run great for like .......7 -10 seconds ...then slowly started dwindling down in rpm trying to die. So I kept noodling with the pedal & attempted to hold it at 2ooo rpm, but it takes pumping the pedal to keep it running. Holding staedy it will just die.
This may be a good time to mention ......NORMALLY i can always smell the exhaust and the closer you get to the exhaust,the more it seems to be running a bit rich,NORMALLY ....but I just noticed that I dont smell that "running rich" smell at all. hmm so confused here. Gonna go out & take off the "IAC" ,carefully.

[88AMCOMANCHE]

took the IAC off (2 torx screws) ....I was expecting lots of crud & buildup, but even though its black, it doesnt nowhere near look very built up or bad. Unless the round piston looking part that goes inside is suppose to be super clean...in THAT case its pretty dirty. i need a camera. Should i wipe the dirtiness off this thing??? or does it need the oily residue to work right?

[88AMCOMANCHE]

maybe its my fuel filter. thing only has about 20 miles on it. but i replaced the fuel pump so maybe it sturred up crap in the tank,who knows.

[jccatt]

maybe its my fuel filter. thing only has about 20 miles on it. but i replaced the fuel pump so maybe it sturred up crap in the tank,who knows.

When looking for a fault always look at what may have caused it. This is a rule for fault finding, i always ask what did i do last. Your answer is above, good chance this is the cause so start there first.

[default83]

yeah if you just replaced the pump, it sounds like insufficent pressure/fuel causing it to choke out.

again this could be why you dont smell the rich smell anymore, there is not enough fuel to burn to cause it to run a little rich.

id check fuel pressure.

[88AMCOMANCHE]

I just took the fuel Filter off, back flushed it manually & got a bunch of crap out of it & did it till it appeared clean. Once i seen this I was sure it was the culprit. So ,once it ran clean I put it back on & tightened it down. Turned key on to prime it and then styarted it up. It firedright up ........ and ran for about 20 seconds perfectly,then gradually died. Im suspecting the sock filter may have fell off in the tank. Bcauase several small chunks came out of the exterior frame filter,Plus a bit of small stuff. NOW when i press the pressure release button n teh fuel rail,I do atleast get SOME pressure but I have no way of testing just how much. but before i wasnt getting hardly any.The gas would drizzle a few drips out. so its an improvement but still isnt staying running.

[88AMCOMANCHE]

UGH ........Just removed the fuel pump inside the tank,AGAIN! the sock was still on,although a bit crookd. The little rubber boot which does almost nuthing but padding at the very very bottom,is rollingaround bottom of the tank,I tried fishing it out but I couldnt get it. It fell of the First time i put the pump in,did just fine without it. .........BUT- I notice....the tiny gas line that connects the PUMP up to the metal line then goes out of the tank......was slid up & the hose was barely even finger tight on the pump. DuNno what this would cause.....but it couldnt be good. I FAILED to tighten that tiny hose clamp up before putting the pump assymbly back in the tank. best lessons learned,are the hardest! Perhaps this is the cause of my not getting enough fuel to the engine? hmm Hoping so. I will know in a few hours. / On a good note, the bottom of teh tank looks pretty clean. Use a flashlight. didnt see anything on teh bottom,side from th little rubber knob piece thats unretreivable. .ah,back to my project~

[88AMCOMANCHE]

T e s t r u n went great.

[jccatt]

Sweet. Good work

[oderdene]

good find. congrats bro

[88AMCOMANCHE]

It actually seems to run slightly better than before even. i suppose cleaning the idle air control didnt hurt,even though that wasnt the problem. but still,atleast its done. Think I might try that seafoam stuff. Maybe it will clean down in the throttle body,Im sure its overdue. .....One day i hope to buy a camera. Eventually. Cant do forums without pics. Ya can but pics help i know.

[Mudderoy]

It actually seems to run slightly better than before even. i suppose cleaning the idle air control didnt hurt,even though that wasnt the problem. but still,atleast its done. Think I might try that seafoam stuff. Maybe it will clean down in the throttle body,Im sure its overdue. .....One day i hope to buy a camera. Eventually. Cant do forums without pics. Ya can but pics help i know.

How did you go about cleaning it? I think mine needs to be cleaned bad.

[88AMCOMANCHE]

I just Unplugged it & removed the 2 Torx screws that hold it on & its off. Then i simply took a paper towel & rubbing alcahol & got all the crud off. Im not sure what the exact correct cleaning product would or should be.....But a bottle of alcahol Rubbing)was the best thing I had & it seemed to clean it up like new in less than 2 minutes.