So now I suppose its story time. Firstly I have a 3.0 with a manual transmission. For months now I have been having problems with my trucks idle. It seems to be a popular one of when the truck is fully warmed up and I am shifting gears and depressing the clutch the rpms shoot up to 3000 or 3500 rpms hang there for 3 to 5 seconds and then drop down. As well as it doing this while going up shifting it also does it when down shifting and while in gear on occasion it will hold the rpms where they are like its in cruise. I went to the most popular fixes first. I have replaced the IAC and TPS. I have also cleaned the MAF and throttle body and my K&N filter, plugs and wires, coil pack, and the crankcase vent hose and brake booster vacuum lines. I have searched hi and lo inside the engine bay with brake cleaner hunting for a vacuum leak and have found nothing. I have also tried more than one IAC and none have fixed the issue. So in my angst I finally took it to the dealer today and had them run a diagnostic check. They said that nothing was coming up in the computer but they cleaned the IAC and removed a second set of o-rings that were in there because they were causing a leak which is really funny because I have never put any in there. They said they test drove the vehicle once fully warmed up and could not replicate the problem. Which having checked my trip they went a whopping 11 miles. but it could have happened in that amount of time but didnt and it happened within 5 minutes of me getting in the truck to drive home and it happened many times on the way home. So I unplugged the IAC and now I have not had the problem occur. So is this the 4th bad IAC in a row or what else could be causing this problem. Thank you for your time
Kevin

 

What year is your truck? I have access to info for 99 ranger all makes and models. As far as I know the data I have should be good from 98 thru 2002. I can try to help you if you haven't fixed the problem yet.

 

i just leave my IAC unplugged....i like the way it runs so much better with out it...the only problem is that it idles really low when its cold...so i hooked up a hand throttle to it so when its cold i can kick it up a bit...kinda like a manual choke.....it always throws a code tho...but i just took my check engine light out of the dash so its not on all the time and i have a ultra gauge to read codes every once in a while to see if a new one pops up...

 

I was trying to find out what I could for your problem and all I could find is sticky throttle cable/linkage, vacuum leak or bad IAC. If you could find a shop that could smoke your engine I'm fairly certain you would find the leak.

 

Thank you guys I'm going over to Johns (wvcat) today and were gonna try and figure it out those are the same things I have found for it too but none seem to be the solution. We will get it done though! i will keep you posted.

 

ive looked ofr hours and hours for a vacuum leak...i even tore my motor down toe hte heads trying too see if i had a bad gasket somewhere. i finally found out that my throttle body had some play in it and it was letting air go around it on the sides. not sure if it could be you problem...but try grabbing your butterfly on the side where the throttle cable wraps around and hooks in and pushing it in and pulling it out....if it moves at all i bet that is your problem. i temporary fixed till i could find one at the junk yard that was right for my truck.....i did this by filling the hole in the butterfly with silicone and turning the idle adjustment screw up until it idled at the right rpm again. cause that hole is to let the right amount of air through at idle cause at idle the butterfly is supposed to be shut so no air can go through....but if its worn out air might be getting around it...

 

Thanks t5cents I will be checking that out tomorrow. John and I were spraying cleaner everywhere and at the end we just thought it may be the MAF so I put a different one in. Thought we had solved the problem but then on the way home still the same thing. So tomorrow I will go out and try to see if thats the same problem I'm having thank you I've looked all over that darn thing but it could be it hopefully.

 

ya..try switching your throttle body with one off someones truck that runs right...thats what i did and it ran perfectly with my friends TB so i knew i had to get a new one...couple months later finally a 3.0 ranger came into the junkyard...

 

Good deal I know one of the guys I go to school with has a 3.0 the only trick is convincing him to let me borrow his TB haha. That will be the next step though.

 

There is a PCM reflash for the 3.0 trucks for a rolling idle. If you do not have a Motorcraft IAC i would suggest that too...another thought, what is your base idle with the IAC unplugged? if it is over 500 RPM when hot, you need to clean your throttle body, adjust your TPS to just less than 1v at idle, disconnect the battery for 30 mins then start it up and adjust the throttle stop screw until you are at 500rpm. re plug in the IAC and give that a try

 

ya thats about what mine idled at with out it...but i just turned the adjuster screw up till it was at about 700-800....but it is still at like 500 when cold and thats why i put in the hand throttle...so i can kick it up a little and it stays there until i push it back down when its warmed up....i like it...but some might not like having to do that..to me its worth it not having it hold rpm's when i shift and staying high till i completely stop...and it revs down a lot faster with out it so it sounds cooler when you are reving it...lol

 

I did end up putting a motor craft IAC back in on the last one although it does look different than the old one. It does idle over 500 when the iac is unplugged because I've driven it like that a few times now. Hopefully tomorrow I will be able to mess with it but I'm in school from 8 to 5 and it's already dark by the time I'm home. But I will try to work that in tomorrow. More ideas are always helpful Thank you.

 

I have a 95 3.0L v6 manual , with the EXACT same problem. I've been very frustrated with this problem and i'm still dealing with it. Did you ever find a working fix for this?

Thanks in advance!

 

I've been dealing with my son's truck...he swapped me...ha ha. I'm guessin it's been an issue for a long time. I have a rough idle issue...very rough. I removed the battery cable while replacing some parts to clear a code and now...high idle. I too disconnected the IAC and that fixed the problem but...that's not how it's suppose to work. LOL

I want to check the throttle body but also the crankshaft sensor. I do have an oil leak (my fault) at the timing cover and I think it is the shaft seal for the harmonic balance.

My mechanic buddy has spent all of time with the truck, I've spent 3 times as much and we still have the same problem. Rough idle, now high idle. I'm getting 20MPG but damn...this is a PIA.

That dirty SOB friend of mine left a home made test cable for the injectors laying on the control arm. I spent 45 minutes trying to figure out where it went. LOL

Smoke test revealed nothing, new injectors, new coil...tested the wires (I'm thinking about replacing them even though they are motorcraft and have only 10K miles on them) 290K miles on the truck, recent head work(a story in itself), timing chain, etc...

I'm interested in this outcome.

Cheers,
Gene

By the way, the reason I'm working on this truck is because I have a VW TDI (2006) that blew up and I need to get to work (106 miles per day). Never complain about your Rangers. VW is Crap !!!

 

Hey...you can help me. My buddy just bought a $3K Snap-On analyzer in addition to his Solus. We are going to put that on the engine and see what happens.

I also have a friend at work that is a former service manager for Ford and he is an excellent mechanic. I'm sure he could fix it if he had the proper equipment but I don't want to put him out. He helps me enough. I take the Solus out for lunch, play around and give him the readings. Something about my (long something trim) on a particular bank of cylinders it reads a negative 14 while the other side is like a 2. This is consistent. He says something is telling the computer to lean out that bank. We smoke tested for the vacuum leak, compresson test, starting fluid, fuel pressure, replaced the coil, plugs, IAC, checked the EGR valve (and I mean really checked, I even made a block off gasket after doing all the other checks)

Mike says that 3.0s don't idle all the smooth anyway but mine is really bad.

So, the reason I did the head was because the valves were about 1/4" sunk into the seat area. But that is another story that might be related... who knows ?? I'm thinking throttle body.

Cheers,
Gene

 

Throttle body, and IAC have been cleaned, still having the problem occur. I'm going to get the throttle cable replaced (mine is a bit rusty); I hope this fixes it. Will keep you guys posted.

-Chanse

 

I don't think changing the throttle cable will help. I was thinking the same thing on mine. I have allot of slack on my throttle cable at idle so I'm sure it is not hanging up because of the cable. Check your slack first, before you replace it. I'm sure you know that idle is not set by any external adjustment. Its the PCM or whatever the hell.

Good luck Grasshopper. I'm pulling the throttle body in the morning. Gone git sum...takin it ta da hole !!

Cheers,
Gene

 

Throttle cable was replaced, issue is fixed! The ranger is running great!

 

Unbelieveable. Mine would never be that easy. Glade to hear that worked for you.
Did you have any slack in the cable? I have allot. I ended up siliconing the hole in the butterfly in the throttle body which brought the RPMs down and I have the IAC connected like it is suppose to be. It is much more driveable now. It idles allot beter but I haven't checked the RPM and I have a check engine light which may help out. I thinking same old, same old, misfire #5 (I've replaced everything now except the cam sync and computer so it's gonna get interesting frome here.

The real point is that the silicone is only masking the real problem which obviously is...it's gettin too much air from someplace. I'm changing the Cam sync this weekend...if it makes it to then.

Take Care,
Gene

 

Hey guys sorry for the late reply i have been moving and am just getting settled into my house. I have checked my throttle cable as well and it seems fine but I have not been able to get another TB to throw on it so who knows Im still running lean on both banks and have been too involved with the new job and fixing up the house to get anything done. Mine definitely is still running like crap so maybe soon I will be able to help figure this all out.

 

I don't know if I Posted this in THIS THREAD but mine is running lean on the drivers side. -13. Whatever that means the passenger side is about 2. I'm not sure plus or minus Hey, I just remembered...I have this from the Solus;

Fuel pw1(ms) 2.6................................... Fuel pw2 (ms) 3.2
LFTRIM 2 (%) 2.....................................LFTRIM (%) -14
SFTRIM 2 (%) -1.................................... SFTRIM 1 (%) 0

RPM 1036 TO 988 (IT VARIES)................DTC COUNT 1
MAT gm/s 654

adv 12% ...............................................RPM DES 896

---------------------------------------------------------------------------------------------

That's my numbers. Whateva dey mean... LOL

Cheers,
Gene

 

CHECK your EGR LINE to the Exhaust manifold. Mine is cracked and might be the source of the whistling noise I've been hearing as well as the EGR code I get once in a great while (I tested the EGR 6 ways from Sunday, I knew there was nothing wrong with it). My new line is on order and should be here on Tuesday. I'll post up on the end result.

Take Care,
Gene

 

Replacing the EGR line did nothing but cure the exhaust leak. So now...I've changed parts that were bad and some that weren't. I still have a rough idle and high idle. I unplugged the whole in the butterfly in the throttle and the engine went way high idle on me again so...I plugged the hole back up. It is driveable but still has a very rough idle. What I haven't done yet is, swap the throttle body with another one or swap the computer or reflash the computer.

There is little left to do with this crazy truck. It seems that it is getting air from someplace but we did everything to locate a leak and can find nothing (smoke test and all). It may be the computer. Who knows ??

Good luck with yours !!

 

Update... all the parts changing did the truck good but it never smoothed out the engine. Funny thing, the mileage is still around 20mpg or a lil more. Runs rough. My mechanic buddy has it at his shop again, I'm in no hurry this time. (Got my 2006 Beetle TDI back on the road 40+mpg and $5k+ later :) )

Danny says it' is now missing on number 5 cylinder and number one cyl. We've always suspected a vacuum leak but have not found anything. He is gonna smoke test it again. This is gonna be wierd, I'll post up when we finally solve the problem. Idle still too high, still have the tape on the butterfly in the throttle body keeping the idle down. LOL This is a joke !!

 

Update from me too. A couple of weeks ago it finally went to something worse and I started getting misfires on the entire drivers side bank of cylinders on start up and while driving on the highway only over 3k rpm's though. So I am really thinking that this is a computer issue since it is only seeming to happen in my open loop. I also had detonation occurring over 3k rpm's so I had to quit driving it just to be safe. Sitting at a mechanic buddys house now to do a compression test and fuel injector balance test and if its not those it looks like I will be replacing the computer. But not to much of a worry not having my truck just picked up a 1997 Jeep Cherokee with 190000 miles for 750 bucks! Totally awesome I have been driving my dads with 330000 miles on it so decided it would be a safe bet. Jeep runs amazing I'm sold on one I think I will honestly sell the truck once its fixed and buy one for myself. Well a stick and I'll give this one to my wife. Whose Jeep we are trading in on a Passat TDI haha. Cant beat that MPG!