95 standard 2.3 has over 200k. Running poorly so i started doing some catch up maintenance.A big issue was it would die at idle and you could feel it not pulling hard at low rpms/low power band etc. I went through and threw some money at it because quite honestly ive spent little on it and it was just time......changed o2 sensors,fuel press reg. (has year old fuel pump due to guage) new idle control valve(also made sure passage wasnt clogged) All this made it run smoother but it never fully corrected the problem.....the problem eventually got worse so i changed the plugs,wires and then the coils.---It still runs like garbage at low rpms especially when its cold.
I havent compression checked it yet but there is no water in oil or any other reason for me to suspect that.Meant to before i put my new wires on---seriously dont think its the problem but since idk.. then who knows.
Also i havent checked fuel pressure but i dont understand how that could be since it runs pretty decent at speed.Can easily cruise at 70.
I have no clue as what to do other than this.....any ideas as to anything else i could check?????----thanks in advance.

 

If you have a lit CEL, run this puppy by your favorite autoparts store for a no cost computer trouble code scan & post All code Numbers, as they can offer up good trouble shooting clues.

Whos plugs & wires did you use & did you check/set the gap & install with a torque wrench to spec????
How did the old plugs read look????

Has the PCV valve been changed in the 200K???

I have more questions, but will wait until you post about the CEL to ask.

 

I just kinda went throught the same with my 94 4.0. Changed everything in the ignition system, sent it to a shop who checked everything and were stumped as to the problem. Finally I changed the injectors and guess what, that was it. Now in your case You have a BELT for the timing I believe, so I would suspect it may have jumped a tooth or is stretched and causing your issues. Particuylarly with 200K on the engine. I had my injectors cleaned at approx 130K (several years ago) so they were the last things on my list of possible problems and had recieved a so-so bill of health from the shop. I really thought after all I had done prior to the injectors that the tiing chain had stretched and needed to be R&R'd. So check your maint requirements in the book and see the timing belt chaing req't and also try a can of SEAFOAM in the tank to see if it helps. Regular use of such a product can help, but can also cause issues as it may clean junk fron the gas tank. Also when was the last time you changed fuel filters?

 

PAW PAW-- There is no engine light. I used champiion plugs and i forgot the brand of the wires.They were made in the usa if that helps. I gapped them correctly....and cmon man you know i didnt use a torque wrench on the plugs... ---------- i dont know why but i didnt even think about the pcv valve. It has been replaced before but i think i might replace it again.

HANK--I replaced the timing belt probably 30k miles ago.I replaced the fuel filter not long ago either, when i replaced the 02 sensors and all that just forgot to mention it.About 30k miles ago as well i had an intake leak and i replaced all my intake gaskets.When i did i looked at the injector nozzles and .....to an untrained eye IT APPEARED to be good. i dunno if you can see a clogged inj or not but these seemed fine....if they are working properly is another question i guess.
If it was not getting eneough fuel it would see it should be more noticeable at higher speeds though wouldnt it?

 

Just wanted to add that not only does it run poorly at low rpms/every gear at low power band etc but it also will not hold an idle 80% of the time and when it does its horrible.It will die when reving it high and completly letting off the gas.

 

Have you checked your tps? . Sure could be a cam timing issue.

 

Does the CEL light up at KOEO for its self test???? If ok & No CEL lit & it runs poorly means its time to pull out your scantool & have a look at the sensors & any pending trouble codes. If you don't have, or can't come by a scantool that'll read sensor PID's then break out your vacuum gauge & see what it suggests is wrong. Here is a thread with a link on how to do a quick engine diagnosis & interpret what the vacuum gauge is telling us.
https://www.ford-trucks.com/forums/8...-tutorial.html

An acting out IAC will mess with idle & is a common problem part. So are vacuum leaks & the vintage of your ride suggests they should be on your suspect list. Dirty MAF sensor too. So many suspects, so few clues, so you need to do some basic trouble shooting & post more clues.

Let us know what you find.

 

I dont have a scan tool or a vacuum guage.I had a regular code reader but it seems it sprouted legs and walked away...
I replaced the IAC already.
i would investigate further with a vacuum guage but i wanted to ask about this...
While it was idling..chug a luggin at probably about 450-500 rpms i unplugged the tps and there was no change. Plugged it back in and unplugged the sensor that goes into the "rubber hose" part of the intake....if anything changed it was a TINY drop in idle speed...but that is an IF. Plugged it in and then unplugged the mass airflow sensor in the airbox with the filter (not a proff mech forgive my words) and idle increased to probably about 650 or so.It was immediatly noticeable and sounded much better.Ran much better with it unplugged than it did plugged in.Not perfect but much better.
So what does that mean? Is the mass airflow sensor bad? What about the tps sensor? Or is all that just a symptom of something else?

 

Well since you don't have a scantool, or code reader, but seem to have gotten a positive trouble shooting response by disconnecting the MAF sensor, maybe consider removing, letting it cool & cleaning it with CRC or Valvolene MAF sensor spray cleaner. Don't touch the sensor with the spray wand, let it dry in a clean place & keep it squeeky clean on re-installation.

Then start the engine & see if idle improves. If so, disconnect the battery B- cable for say 15 min with a door open, to wipe the KAM corrupt fuel trim tables & warm & cold idle memory. Then turn off All electrical loads & reconnect the battery B- cable, start the completely cold engine & go through the cold & warm idle relearn proceedure & see how it goes. EDIT: Idle relearn https://www.ford-trucks.com/forums/s...9&postcount=12

If no joy after cleaning the MAF sensor, Don't disconnect the battery B- cable, but come by a scantool, code reader, or take it to your favorite autoparts store for a trouble code scan & post All code numbers found.
Again, does the CEL light up for its self check????

 

I tried cleaning the maf sensor once before....before it got really really bad. Maybe i didnt clean good eneough maybe it was uncleanable i dunno...maybe because i didnt know about any of the other procedures to go through. It didnt change anything.Thought maybe i just had a bad one.I live about 25 miles away from the nearest parts store so I just bit the bullet and bought a new one since i was nearby today. This problem was killing me i was having to rev it up everywhere and drive it as if it were a race car keeping the rpms up.....its been a pain.I never even really had an issue with maf sensors before...they just sorta worked...anyway i bought a new one and it actually idles.I am having to relearn how not to have my foot on the gas and brake at the same time.
All is much much better...BUT i can still make it die if i rev it high and hold it for a second and then let go. With that TPS not changing when i unplugged it could that be a problem? Or would it help even though i bought a new maf sensor to go through the steps of "teaching" it etc?----what could allow this to happen?

The problem in the real world driving is that if i slow down to turn into a drive or parking spot quickly there is a chance it will die(did before the maf and i am sure it will do it now as well just not near as often)) and when it dies i have no power steering leaving me aimed straight for a car coming out of the drive.

 

Good to hear the new MAF sensor has improved things.

Now you need to find out Why the old one was acting out, as its to only see filtered air!!!!

So look up stream to make sure the air filter, air box & air tube are fitting ok, in place & properly buttoned up.

If your using an oiled foam, or cotton gauze type filter, is it overoiled, if so, it can contaminate, uncalibrate/corrupt the MAF sensors heated wire air flow sensor PID to the computer, about true air flow into the engine & that'll cause the computer to have the fuel injectors mess up the air/fuel ratio, all a vicious circle????

When you went by the autoparts store & bought the MAF sensor, why didn't have them do the no cost computer trouble code scan???? Trouble code Numbers can give good trouble shooting clues.

Try going through the cold & warm idle relearn proceedure & see how idle goes.
If you still have problems, try disconnecting the IAC & post what happens.
If idle is still rough, look for a vacuum leak.

 

I am using a non oiled filter. It is pretty new...but i did notice it was dirtier than i expected it to be when i took the sensor out.Everything was fitted together properly....put it back together no problem.
No engine lights were on so i didnt think they could pull any codes.--hoping my code reader shows up/misplaced...if not i can take it back in if something would show up.
It idles good now just it will die if i rev it high and let off quickly. Just sitting there at idle it is fine now.
I will try that cold warm idle procedure thing asap.--thanks.

 

Pending codes can be stored that haven't happened often enough to have the computer turn the CEL on.

As sensitive as the system is, its strange that the computer didn't turn the CEL on & set an MAF sensor trouble code.

Does the CEL light up for its self check at KOEO before you crank the engine????

EDIT: Yup, do the KAM wipe & idle relearn, so the old fuel trim tables & idle strategy are wiped & the computer knows a repair has been made, so it can begin to rebuild new fuel trim tables with input from the new MAF sensor.

 

ok back again----after replacing the maf it ran/idled much much better when it was warm.Cold it still struggled...replaced the tps (over 200k fer sure so yeah i crossed my fingers and threw some money at it)....it runs better now when its cold but it wasnt a giant improvement like with the maf.----Now it runs pretty decent at speed and will idle decent when it is warm but when it is cold it still is not too good.Also it will die when revving high and letting off.Such as driving in parking lots or making turns into entrances.Its a pita. ---I found my code reader,showed no code light but after clearing the ecm it showed the front 02 sensor bad.Read it later it showed front and back 02 sensors and miss at cyl. 2. Wires and plugs new. 02 sensors replaced not long ago.-----------dont know how to read this or what to make of it. --any help is appreciated.

 

Just a thought here, hows your Coolant temp sensor? If it is reading the wrong temp or even if the connection is bad it can cause fuel delivery problems especially when cold.