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Ranger 3.0, poor idle and acceleration

Fordzilla80

Ranger Lariat
6,372
262
Narnia
Recently for the last few weeks i've had a big problem with my 03 Ranger. Whenever I start the truck up in the morning, it runs great. But as I drive, about 15-20 minutes into driving the truck will develop a jumpy idle at stops. It'll fluctuate between 500 and 1,000, and occasionally it dips below 500 and completely stalls out. When I go to accelerate, the truck will start going, then it just completely bogs down for a second or two, then it comes out of the bog and returns to normal. The warmer the truck gets the worse this gets until eventually it happens at every single stop. It just recently threw two codes, one for the IAC and one for the IAT. But I previously unplugged the IAC and MAF to test them out while the truck was running, so I think that's where those two codes came from.

Things i've checked:

-TPS
-IAC
-MAF
-Cleaned the Throttle Body and linkage

One thing I noticed is that I may have a vacuum leak somewhere around the intake, towards the back of the motor. It doesn't seem like the intake though, as it's not significant. It's just a constant sssssss that seems muffled, like it's under the intake. Is it possible that one of my injector seals is bad? If it helps any, the truck only has 48,000 miles on it. I greatly appreciate any suggestions.
 
Last edited:

blacksnapon

Moderator
Staff member
TSB
05-22-12 BUCK/JERK AND MISS DURING DRIVE CYCLE ABOVE 3000 RPM - NO DTC - 3.0L 2V GAS AND FFV ENGINE

Publication Date: October 25, 2005

FORD: 2000-2003 Taurus, Ranger
MERCURY: 2000-2003 Sable


ISSUE:
Some 2000-2003 Taurus, Sable, Ranger vehicles equipped with a 3.0L 2-valve gas or FFV engine may exhibit a buck/jerk/miss during drive cycles above 3000 RPM with no diagnostic trouble codes (DTC's). A possible cause is the camshaft synchronizer assembly. Since the camshaft position (CMP) fault monitor is not active above 2500 RPM, no diagnostic trouble code (P0340) is set during the drive concern, thus making it difficult to diagnose the root cause component.

ACTION:
Use an NGS to identify whether or not the synchronizer is the causal component. Refer to the following Service Procedure.

SERVICE PROCEDURE

Select PID database.
Select "Fuel Priority" PID database.
Select KS1 and RPM PID's.
Capture data during drive symptom.
Using graph mode, display KS1 and RPM.
Look for knock errors which can be identified by rapidly rising peaks which correlate with drops in RPM (Figure 1).
If the synchronizer assembly needs to be replaced, follow the appropriate model year Workshop Manual, Section 303-14, Electronic Engine Controls, Camshaft Synchronizer - 3.0L (2V) Removal and Installation procedure.
 

d-kuzmen

Master Ford Tech
2,109
79
Connecticut
You can use water to check for a vaccume leak. Pour some water around the intake and injectors, if you hear it sucking the water in you will know where you have to look. What happened when you unpluged the iac did it stall or continue to have rolling idle?
 

Fordzilla80

Ranger Lariat
6,372
262
Narnia
Thanks for the replies!

Blacksnapon, I am aware of the problems with the Cam sync on these 3.0 and 4.0 OHV Rangers, however I do not believe this is my issue. My truck doesn't have any trouble above 3,000 rpms, in fact that's when it runs best. My problem is below 1,000 rpms. Also, it isn't really a buck/miss/jerk, it's more of a bogging down, and there are no discernible chirping sounds coming from the area of the cam sync.

D-kuzmen, I have unplugged the IAC, and the idle momentarily drops down, but then it comes back up and seems to regulate itself. I did not pay attention to see if it still gave me the same issue, will go and try that in a few minutes. As for the vacuum leaks, water is a good idea. Without the upper intake plenum removed I have pretty much no access to the bank 2 injectors.
 
Last edited:

Fordzilla80

Ranger Lariat
6,372
262
Narnia
Update: I went out and unplugged the IAC, and the idle dropped down to around 500 rpms. However it did not fluctuate. I decided to check something else, and then I decided to try and unplug the IAC again. Now when I unplug it nothing happens?
 

blacksnapon

Moderator
Staff member
Yeah, looking for that vacuum leak would be a priority. The IAC motor is essentially just regulating airflow. If theres a leak, the IAC cant regulate it that much. I usually use a can of carb cleaner with the straw. The straw will allow you to pinpoint the leak closer.
 

Fordzilla80

Ranger Lariat
6,372
262
Narnia
Yeah, looking for that vacuum leak would be a priority. The IAC motor is essentially just regulating airflow. If theres a leak, the IAC cant regulate it that much. I usually use a can of carb cleaner with the straw. The straw will allow you to pinpoint the leak closer.

Thanks man! I'm waiting for it to cool down outside, but as soon as it does i'm gonna see what I can find. I hit the injectors with a little water, and no discernible difference in idle. I'm gonna try again, but as BlueGoose suggested to me a length of hose and your ear will get me a better indication of the exact location of the sssss sound. I'm gonna try the upper intake plenum seal, the lower intake seal, the pvc elbow, and any other vacuum source on the back of the motor. I'll update what I find. I'll update with what I find.
 

Fordzilla80

Ranger Lariat
6,372
262
Narnia
Been narrowing things down. I don't know what i'm hearing but it isn't a vacuum leak. Truck is pulling 18" hg of vacuum at idle. Haven't yet checked it under load, but I wouldn't imagine it would make any difference. The water test came up with nothing at all. Neither did Carb Cleaner. I replaced the deteriorated EVAP purge valve hose that connects to the upper intake plenum, but that didn't do much of anything. I tested the new TPS, and couldn't get an accurate reading from it after multiple tries. Since it was still new and had a 2 year warranty, decided to take it back for a replacement. I put the new TPS on, wiped the KAM, went back through the idle re-learn strategy, and it's still doing it. One thing I did notice is that if I just gradually apply the throttle, then it's fine and doesn't hesitate or bog down. It's just when medium to heavy throttle is applied. So taking that into account, it kind of sounds like a fuel starvation problem to me, like the computer can't pull fuel fast enough to the injectors. It hasn't had a fuel filter put on it to my knowledge since 2005 at 25,000 miles, so i'm gonna pull that off and blow through it to see what kind of resistance I get just to see if it's clogged up. If it is i'll replace it. If not, i'll be doing a fuel pressure test to see what i'm reading for that.
 

d-kuzmen

Master Ford Tech
2,109
79
Connecticut
If the fuel pressure is ok I would recomend unplugging the MAF sensor and driving it to see if it's any better. A faulty MAF can give you the boging down if it's unable to determin the amount of air entering the engine, or if the baro sensor (part of the maf) thinks your up in the mountains it will do screwy things.
 

Fordzilla80

Ranger Lariat
6,372
262
Narnia
If the fuel pressure is ok I would recomend unplugging the MAF sensor and driving it to see if it's any better. A faulty MAF can give you the boging down if it's unable to determin the amount of air entering the engine, or if the baro sensor (part of the maf) thinks your up in the mountains it will do screwy things.

I haven't gotten around to the fuel pressure test, but i'll definitely try unpluggin the MAF on my way to work to see if it does any better. Thanks for the suggestion. :)
 

Fordzilla80

Ranger Lariat
6,372
262
Narnia
Well recently I unplugged the MAF and drove the truck. As soon as I started to go, it seemed like the transmission went into fail safe mode. Every single shift was hard. But no O/D Off light. So maybe 2 minutes later I pulled into a parking lot and plugged the sensor back in, and it went back to normal. I'm still having the hesitation issue however.

Some new developments have come up that may better explain my issue. Ever since I've owned the truck I have been battling a P0741 TCC Circuit Performance code. It seems like whenever I'm going down the highway, and I maintain constant speed the truck will go into overdrive, and gain a very slight vibration. This is when the O/D Off light will start to flash. However if I manually keep the truck from going into Overdrive by adjusting my speed around, then the O/D Off light does not come on. Now, somebody elsewhere mentioned to me that the problem I'm having sounds like a T/C lockup issue trying to stall my truck at stops, like a manual trans vehicle would. And to be honest, it makes a lot of sense since the idle only jumps when I'm in reverse or drive. Whenever I put the truck in park or neutral, the idle immediately goes up and holds at 800. It's just whenever the load is applied, the idle just gets absolutely crazy. Now, this only happens when the truck warms up. When the truck is cold, it's absolutely fine. Does this have to do with the truck being in open vs closed loop? Originally I thought I may have a gasket leaking vacuum. Is it possible my separator plate gasket is blown, causing the symptoms to get worse as the truck and trans warms up?

I really appreciate the help guys, I feel like I'm so close to knowing the problem, I just need these few things cleared up.
 

Fordzilla80

Ranger Lariat
6,372
262
Narnia
Alright guys, after 4 months of trouble, I may have found what was wrong with my Ranger. It turns out that that the bolt that holds down the TCC solenoid is completely non-existent, and the retaining tab for the TCC solenoid on the solenoid bracket has torn halfway off the bracket. Both of these factors allowed the TCC to slip out of it's bore. Since the TCC solenoid controls lockup for overdrive, overdrive was directly affected. The computer waits until the transmission warms up before it commands lockup, so when the truck is cold, the TCC is not commanded to do anything. But as soon as the truck warms up, the TCC gets it's command, but due to it's position out of the valve body bore, it causes the torque converter to lockup and stay locked, thus trying to stall the truck at stops, causing the hesitation at acceleration, and causing the surging idle. This may have also caused the O/D Off light for TCC stuck off that I've battled since I first got the truck.

So tomorrow I will be off to Ford to order a new updated solenoid bracket, and then Friday I will head to the junkyard to grab the TCC solenoid bolt from a junkyard truck. That is, unless Ford has the bolt for cheap and in stock.

Here's a pic I took of the carnage:

picture339o.jpg
 

Fordzilla80

Ranger Lariat
6,372
262
Narnia
Alright, the truck is finally fixed permanently.

Total Cost:

New Solenoid Bracket from Ford: $12
Mercon V Transmission Fluid: $60
My Labor/Time: $Free.99

Total time to replace parts: About two hours total including pulling the bolts from the junkyard truck.

First off, EVERY single issue described before, and every single issue I've ever had with this truck is now gone. As a recap, this all started two weeks after I bought the truck in September 2010 with an intermittent O/D Off light and P0741 code. The only symptom was high rpm change when shifting into reverse or drive, and a surging idle in reverse. Learned how to change my driving habits, and that helped me keep the O/D Off light off. Anyways, in April 2011, I had to go through a small mud hole, and a pretty washed out limerock road. Well, I ended up developing a surging idle in drive as well, severe hesitation upon acceleration, dropping out of gear (or rough O/D engagement) at highway speeds, and low rpms in gear at about 600. After this repair, the truck now idles at 850, the rpm change when going into drive or reverse is only about 50 rpms, there is no more surging in idle in reverse, or at stops, and there is no more hesitation.

Now for the final pics:

I grabbed two bolts at the junkyard just to be safe, but none of the other bolts were missing, so I didn't need the other one.


picture378j.jpg



New bracket on top, old one on bottom. You can see where the TCC tab is clearly broken off.


picture379w.jpg




New bracket and TCC solenoid/valve body retaining bolt installed.


picture381w.jpg
 

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