Stumble in Idle on 3.0 Vulcan

[Blitz]

I bought a 2002 Ranger Tremor with 79,000 miles on it from an old farmer who did nothing more than change the oil for entire life. Tires were from 2009 and original wires and plugs. Needless to say I have spent a small fortune trying to get the maintence up to par. It has a glitch in the idle and I can not seem to fix it. So far I have replaced spark plugs, wires, coil pack, cam phaser and the 90 degree hose that comes out of the PCV valve. I have cleaned the IAC valve and had throttle body cleaning done. I looked for the EGR valve but it seems to be missing. The funny thing is my brother bought a 2002 ranger Tremor that is only a few hundred off on the vin number and his truck is missing EGR valve as well and idles is the same. Is this how all Vulcan motors idle? or does it have to do with the EGR delete and how common is this practice? Really strange that both trucks are missing this part.

 

[RonD]

2002 Ranger 3.0l did not have an EGR valve, but did have a Knock Sensor

"Glitch in the idle"?????
Like random misfires?
Or a stumble when you press the gas pedal down to accelerate under load, i.e. driving?

Does the symptom change when engine is cold or warmed up?


EGR system is used to prevent spikes in cylinder temps when engine is under a load, so not used at idle
Knock sensor is used for similar, if ping/knock is detected computer will change spark timing to reduce cylinder temps
EGR system is slightly better at this so more common to use, but it also depends on Emissions standards for the year of the vehicle
Higher cylinder temps spike emissions of NOX, a toxic gas

 

[rusty ol ranger]

Is it a stumble or a tremor?

Every ford ive ever owned has idled with a slight "tremor" in park

 

[Blitz]

2002 Ranger 3.0l did not have an EGR valve, but did have a Knock Sensor

"Glitch in the idle"?????
Like random misfires?
Or a stumble when you press the gas pedal down to accelerate under load, i.e. driving?

Does the symptom change when engine is cold or warmed up?


EGR system is used to prevent spikes in cylinder temps when engine is under a load, so not used at idle
Knock sensor is used for similar, if ping/knock is detected computer will change spark timing to reduce cylinder temps
EGR system is slightly better at this so more common to use, but it also depends on Emissions standards for the year of the vehicle
Higher cylinder temps spike emissions of NOX, a toxic gas

It does it at idle no matter if cold or warm. Might be a little worse when warm. I will check analyzer tomorrow to see if any misfires. Its idles smooth as glass but then randomly stumbles and shakes the engine just a touch. Under load it runs fine. No big deal really. I am more curious than worried. Every part I have replaced so far has made a difference. The biggest difference has been the collapse 90 degree hose out of the PCV valve and the Coil pack that had 4 cracks in it.
Thanks
Blitz

 

[rusty ol ranger]

It does it at idle no matter if cold or warm. Might be a little worse when warm. I will check analyzer tomorrow to see if any misfires. Its idles smooth as glass but then randomly stumbles and shakes the engine just a touch. Under load it runs fine. No big deal really. I am more curious than worried. Every part I have replaced so far has made a difference. The biggest difference has been the collapse 90 degree hose out of the PCV valve and the Coil pack that had 4 cracks in it.
Thanks
Blitz

That sounds normal actually.

 

[Burnsy]

Fuel filter ? Try some stp fuel injector cleaner,can't Hurt, been using it for years on my rangers they like it,white bottle is reg strength, black is super concentrate id try black bottle with full tank of gas,......hows your air filter look ?

 

[mc17eln]

randomly stumbles and shakes the engine just a touch

I have the same issue, a small vibration during idle. Once the truck gets moving, I can't feel it. FORScan shows a very low misfire count: sometimes 5 to 9 counts for a 20 minute trip, sometime 0 counts. Regardless of the misfire count, the vibration is there at idle, cold or warm.

I did complete rebuild, keeping only the block, crank, cam, synchronizer, injectors. I am putting this vibration in the live-with-it column.

 

[Blitz]

Update: Addressing the Burnsy question about the fuel filter. yes I had it replaced a couple weeks ago. I have run 3 cans of Gunk fuel system/injector with PEA cleaner through the gas tank a month ago. I also tried a tank of 93 octane and that made no difference with the idle. I just did a total reset on the ECM last weekend and now it runs even better. I did not make it over to my brothers house with the analyzer yet to check misfires. with all the things I have done this thing runs like a scalded dog compared to what I started with except for the idle that is not smooth as I think it should be. for anyone interested I will keep trying to solve this issue. For the older guys out there, back in the day I had a 1981 Oldsmobile Starfire Firenza with an odd fire V6 engine and that is exactly how this Vulcan is idling.

 

[Blitz]

I have the same issue, a small vibration during idle. Once the truck gets moving, I can't feel it. FORScan shows a very low misfire count: sometimes 5 to 9 counts for a 20 minute trip, sometime 0 counts. Regardless of the misfire count, the vibration is there at idle, cold or warm.

I did complete rebuild, keeping only the block, crank, cam, synchronizer, injectors. I am putting this vibration in the live-with-it column.

(I am putting this vibration in the live-with-it column.)
I think there might be a lot of Vulcan Ranger owners living with this idle issue. I am going to try to solve.

 

[Xrundan]

Yeah, my Vulcan does the same thing. Mine, though, also has pretty strong hesitation during acceleration from time to time. Very annoying.

 

[Ranger850]

Sometimes, with cheaper plug wires, if they are touching, it can cause a crossfire. Make sure to use the little wire spacers anywhere they run parallel to each other or cross over another wire.

 

[Fast Eddie]

Mine's rhythmic. You can almost count the seconds until the next 'stumble'.

 

[Blitz]

Well I just changed out the IAC valve and it made no difference. Funny thing is I gave my Ford dealer my vin number and he gave me the new IAC valve that is much bigger than my original IAC. Could the Ford parts guy make a mistake? Look at my picture the smaller one is the original and the bigger one is new.

 

[Blitz]

Sometimes, with cheaper plug wires, if they are touching, it can cause a crossfire. Make sure to use the little wire spacers anywhere they run parallel to each other or cross over another wire.

So far I have used OEM parts from Ford dealer. I know Amazon sells counterfeit Ford parts so I do not buy there. I get a 30% discount from Ford anyway so very competitive.

 

[Xrundan]

So far I have used OEM parts from Ford dealer. I know Amazon sells counterfeit Ford parts so I do not buy there. I get a 30% discount from Ford anyway so very competitive.

Funny you mention that. I just looked around for a Motorcraft IAC for my '01 (I believe the part number is cx1851) and found one on Amazon for under $50. I thought that was a hell of a deal, but I am waiting for it to arrive and have "MotoCraft" stamped on it. We will see.