Misfiring Ranger with the 3.0L Vulcan - diagnosis steps?

At this age and mileage, I'd find all the injectors suspect
New ones are ~$50 or so
Maybe remove them all and send them for cleaning/flow testing?
Or just replace the one
Of course, a fuel filter and a bottle of Techron wouldn't hurt 👀
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A leak down test would isolate a valve issue, of which Vulcans are somewhat known for
If it's still on the original Cam Synchronizer, swap it for a Motorcraft unit, check to make sure the cam sensor didn't get mangled by the tooth on the synchronizer
IAC not sticking?
Not high enough mileage for timing chain stretch?
Inspect the Coolant temp sensor, I remember my Vulcan Taurus being kinda fussy about the OE Motorcraft part
 
So, this is weird. I used a noid light to confirm my findings of a dead injector. I gave the engine a bath to make things more pleasant to work on, and I decided to pull codes again. This time, the P1151/P1152 codes are gone, this time it’s a P0171 to lean bank 1. So the O2s woke up with a bit of water and generic Gunk Engine-Brite then? 🤷🏻
 
At this age and mileage, I'd find all the injectors suspect
New ones are ~$50 or so
Maybe remove them all and send them for cleaning/flow testing?
Or just replace the one
Of course, a fuel filter and a bottle of Techron wouldn't hurt 👀
View attachment 143511
A leak down test would isolate a valve issue, of which Vulcans are somewhat known for
If it's still on the original Cam Synchronizer, swap it for a Motorcraft unit, check to make sure the cam sensor didn't get mangled by the tooth on the synchronizer
IAC not sticking?
Not high enough mileage for timing chain stretch?
Inspect the Coolant temp sensor, I remember my Vulcan Taurus being kinda fussy about the OE Motorcraft part
I got the go ahead to get all 6 injectors, Motorcraft ones too. I’m sticking to my plan of new O2s as well, $24 on Rock for Bosch ones, can’t hurt.

It’s got the OE synchronizer, from what @D60 said here, those will exhibit misfires above 3K RPM.
 
I got the go ahead to get all 6 injectors, Motorcraft ones too. I’m sticking to my plan of new O2s as well, $24 on Rock for Bosch ones, can’t hurt.

It’s got the OE synchronizer, from what @D60 said here, those will exhibit misfires above 3K RPM.
Is Bosch the OEM supplier for the O2 sensors? If not, I would use Motorcraft ones. Did you test the wiring to the #2 injector to make sure it's getting the inputs it needs? You don't want to throw an injector in it only to find out you have a wiring issue or a bad driver in the ECM.
 
Is Bosch the OEM supplier for the O2 sensors? If not, I would use Motorcraft ones. Did you test the wiring to the #2 injector to make sure it's getting the inputs it needs? You don't want to throw an injector in it only to find out you have a wiring issue or a bad driver in the ECM.
On my Vulcan Taurus, NTK was the OE
Reasonable @ $28 each
Also double check the DPFE sensor and it's hoses, they can disintegrate with age
 
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On my Vulcan Taurus, NTK was the OE
Reasonable @ $28 each
Also double check the DPFE sensor and it's hoses, they can disintegrate with age
I only try to use OEM or it's equivalent on any sensors on the vehicle if it's available. Especially on O2 sensors. Most aftermarket sensor are junk these days and even some OEM.
 
I only try to use OEM or it's equivalent on any sensors on the vehicle if it's available. Especially on O2 sensors. Most aftermarket sensor are junk these days and even some OEM.
I get that, I wholeheartedly agree
But paying twice the price for the same part with the same markings in a Motorcraft bag is a bit of a waste on a 1998 🤷‍♂️
Cross referencing OE part numbers derived from the VIN is the best course of action to ensure the correct part
 
I get that, I wholeheartedly agree
But paying twice the price for the same part with the same markings in a Motorcraft bag is a bit of a waste on a 1998 🤷‍♂️
Cross referencing OE part numbers derived from the VIN is the best course of action to ensure the correct part
I agree and that is why I said, "it's equivalent". Like in your case, if the NTK is the OEM supplier for the O2 sensor and it's cheaper, I would have no problem using it.
 
I only try to use OEM or it's equivalent on any sensors on the vehicle if it's available. Especially on O2 sensors. Most aftermarket sensor are junk these days and even some OEM.
The upstream sensors look like Bosch to me. I’ll take another look.
 
I would think that a dropped valve seat would be readily apparent. Just because X number of parts were replaced doesn't mean those replacement parts were good parts.
Wires and plugs are the correct Motorcraft parts for the truck. The truck was mostly dealer serviced as well.

And the factory O2s are Bosch. I’ve ordered those instead of the Motorcraft ones, which appear to be Bosch as well.
 
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Wires and plugs are the correct Motorcraft parts for the truck. The truck was mostly dealer serviced as well.

And the factory O2s are Bosch. I’ve ordered those instead of the Motorcraft ones, which appear to be Bosch as well.
Those should work fine then.
 
I have a 1998 ranger xlt 3.0. Have had it since new. I replaced the synchronizer once around 2012 with an oem. Over the years 3 random injectors have went out. I ended up moving all the new oem injectors to the drivers side under the plenum and all the originals to the passenger side. Now if any of the remaining old ones die its a quick fix with no gaskets or plenums to remove. Its at 226k now and its only had the one syncro, 3 injectors and o2 sensors replaced as far as the ignition system goes.
 
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So, this is weird. I used a noid light to confirm my findings of a dead injector. I gave the engine a bath to make things more pleasant to work on, and I decided to pull codes again. This time, the P1151/P1152 codes are gone, this time it’s a P0171 to lean bank 1. So the O2s woke up with a bit of water and generic Gunk Engine-Brite then? 🤷🏻
Did the bath perhaps improve an electrical connection?
 
I had a 2002 Ranger 3.0 for about 15 years that I sold to a family member recently with around 257k miles. My parents were the original owners so I know the full history of it. It loves cam synchros. Probably on # 4, all Motorcraft. Always had oil in it but was run hard, like one ATV in the bed and two on a trailer on the interstate routinely. The cam synchro issue can show up in multiple ways, usually either a chirping sound or bucking/skipping. At this point I just know when that's what's up.

Also my truck had a weird catalytic converter failure around 150k. It had no power and would misfire bad above 50 mph with a flashing CEL. Replaced the cats and O2 sensors and it was fine after that. Same Walker cats are still on it.
 
installed 6 new Motorcraft injectors - made by Denso, I always thought Ford used Bosch. I buttoned the truck back up today during my lunch and after work. Cleared the codes. Took it on a 10 mile drive, no CEL, all monitors except EVAP are ready. I added a bottle of Techron to the tank, the ports where the injectors sit in were very dirty. The truck probably saw a lot of pre-Top Tier Arco/Costco or the cheapest gas. I’ll run the tank down to nearly empty and gas up again.

I need to replace a few electrical connectors, order a new intake tube from Ford and wallet flush the truck.
 
On my Vulcan Taurus, NTK was the OE
Reasonable @ $28 each
Also double check the DPFE sensor and it's hoses, they can disintegrate with age
I’m wondering how to check the DPFE - I did get a stumble for a 1/4 mile at 40MPH last night but all was fine when I tried to replicate it.

Also, dealer installed new plugs, Motorcraft single platinums. I’m debating changing those to NGKs but they looked good to me.
 
My Taurus had weird misfires / stumbling / pinging for years when I had it. Usually part throttle.

Finally one day, it set a check engine light for EGR flow. Changed the sensor and all of those problems were gone.
 
Clean MAF, see if any change.Check if smooth increase in fuel with increase in throttle.
 
From my experience the 3.0s end up having a lot of timing issues. First thing I would do is a compression check, wet & dry. Drop a few things of oil in the cylinder when you do it. If all checks out good there removing the valve covers and visually inspecting things wouldn't be a bad idea either.
 
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