Misfire

Frankydanks

Junior Member
Joined
Sep 3, 2025
Posts
8
Reaction score
1
Location
Las Vegas
2007 4.6 3v
Codes That Have popped up have been
camshaft position sensor A Bank 2
fuel pressure sensor

Starts fine, idles fine revs fine

Soon as its put in first gear and try to go from a stop car starts misfiring and acts like it wants to die

Replaced FPS, Going to change camshaft position sensor wiring all looks good. Not sure what could it be
 

Dino Dino Bambino

I have a red car
Joined
Aug 11, 2014
Posts
4,509
Reaction score
2,601
Location
Cyprus
Going to change camshaft position sensor wiring all looks good. Not sure what could it be
Don't waste your money doing that 'cause it almost certainly isn't the culprit. The cam position sensor is merely doing its job and telling you that something is wrong.
It's not unknown for a faulty alternator diode to allow AC current to leak into the main engine harness and trigger a cam.position sensor code, so start there first with your troubleshooting.

An AC ripple test is easy to perform if you have a digital multimeter, and there are plenty of YouTube videos describing the process.

You could also try disconnecting the wiring harness from the driver's side VCT solenoid to see if the symptoms improve. The VCT system relies on oil pressure and flow to function correctly, and any obstruction caused by a clogged screen in the VCT could produce the symptoms you described.

If neither of these measures produces a positive result the problem could be a failed driver's side timing chain tensioner or broken chain guide. How many miles has the engine done?
 

Frankydanks

Junior Member
Joined
Sep 3, 2025
Posts
8
Reaction score
1
Location
Las Vegas
as of right now the motor has around 185k miles, i bought a motor from ebay with “80k miles” and it looks worse than my current motor so i want to see if its fixable before i but another motor.
 

Frankydanks

Junior Member
Joined
Sep 3, 2025
Posts
8
Reaction score
1
Location
Las Vegas
Don't waste your money doing that 'cause it almost certainly isn't the culprit. The cam position sensor is merely doing its job and telling you that something is wrong.
It's not unknown for a faulty alternator diode to allow AC current to leak into the main engine harness and trigger a cam.position sensor code, so start there first with your troubleshooting.

An AC ripple test is easy to perform if you have a digital multimeter, and there are plenty of YouTube videos describing the process.

You could also try disconnecting the wiring harness from the driver's side VCT solenoid to see if the symptoms improve. The VCT system relies on oil pressure and flow to function correctly, and any obstruction caused by a clogged screen in the VCT could produce the symptoms you described.

If neither of these measures produces a positive result the problem could be a failed driver's side timing chain tensioner or broken chain guide. How many miles has the engine done?
Alternator Has been tested but not "professionally" i guess you can say, i will add everything back and try out the vct, but i do believe its my cam phaser or a timing issue, is it better to replace it all? or just find a new motor

 

Dino Dino Bambino

I have a red car
Joined
Aug 11, 2014
Posts
4,509
Reaction score
2,601
Location
Cyprus
as of right now the motor has around 185k miles, i bought a motor from ebay with “80k miles” and it looks worse than my current motor so i want to see if its fixable before i but another motor.
My advice is fix your existing motor, especially if it still runs well and doesn't burn oil. At 185k miles you're long overdue for an engine refresh anyway and here's a shopping list of parts for you:

OEM VCT Solenoids: 8L3Z-6M280-B
Ford Performance Camshaft Drive Kit: M-6004-463V
Ford Performance Rocker Arm Lash Adjuster Kit: M-6529-3V
Felpro Timing Chain Tensioner Gasket Set: ES73226
OEM valve stem oil seals: 3L3Z-6571-DA (or Viton valve stem oil seals).
PQY Performance valve spring compressor: VSC07B
OEM '13-'14 Shelby GT500 high pressure oil pump (Ford part no. DR3Z6600A)
OEM 3V oil pump pickup tube (Ford part no. 4R3Z6622AA)
 

StockishS197

Member
Joined
Dec 24, 2024
Posts
435
Reaction score
381
Location
Houston
Alternator Has been tested but not "professionally" i guess you can say, i will add everything back and try out the vct, but i do believe its my cam phaser or a timing issue, is it better to replace it all? or just find a new motor
Make sure to specifically ask for AC ripple. Most parts stores should test for it, but I always make sure to specifically see that result. Sometimes the parts guys only see good voltage and assume it’s good. Voltage can be fine, but AC ripple is high, wrecking havoc on the PCM. Between my 2 3vs, I have gone through multiple alts due to bad diodes.

Every time, it started running rough shortly by a CMP code.
 

Frankydanks

Junior Member
Joined
Sep 3, 2025
Posts
8
Reaction score
1
Location
Las Vegas
just want to sell it now, lost motivation i cant find the issue, i picked up a motor from ebay and it was worse looking than my old one, so i just wanna give up, been chasing down the problem for 3 months
 

Dino Dino Bambino

I have a red car
Joined
Aug 11, 2014
Posts
4,509
Reaction score
2,601
Location
Cyprus
just want to sell it now, lost motivation i cant find the issue, i picked up a motor from ebay and it was worse looking than my old one, so i just wanna give up, been chasing down the problem for 3 months
I wish you'd come to us sooner for guidance. Don't give up though. Just troubleshoot the problem step by step as per my first post and tell us what you find.
 

Forty61

Senior Member
Joined
Nov 6, 2016
Posts
1,427
Reaction score
1,407
Location
Dallas, TX
Maybe a dumb suggestion but how old is the fuel filter? While you have two codes indicating a possible electrical issue, a clogged filter may account for the fuel pressure issue and the rough running when under any load.
 

Kev555

Member
Joined
Dec 12, 2021
Posts
374
Reaction score
170
Location
Ireland
just want to sell it now, lost motivation i cant find the issue, i picked up a motor from ebay and it was worse looking than my old one, so i just wanna give up, been chasing down the problem for 3 months
Stick it out with the Guys on here, you will get to the problem with their help, They have helped me totally rebuild my engine and I knew virtually nothing about 4.6 3v engines. With their help the 3V looks a lot simpler engine than I ever could have imagined.
 

Kev555

Member
Joined
Dec 12, 2021
Posts
374
Reaction score
170
Location
Ireland
Yeah be glad it isn't a 4.2L V8 Audi engine. That one's an absolute nightmare to work on. Trust German carmakers to overcomplicate things! :lol:

Same as Mercedes 2.1 diesel, timing chain on the rear of the engine, WOW talk about complicating things with that timing setup.
 

brasil

Member
Joined
Sep 14, 2019
Posts
391
Reaction score
142
Location
Germany
that´s why I LOVE Ford.. My wife has a 2007 Fiesta..with Duratec Engine .. "Bullitt- Proof "
German cars..or better all European Cars are junk in these days. Expensive.. and poorly engineered
 

JC SSP

Senior Member
Joined
Nov 8, 2022
Posts
2,283
Reaction score
1,353
Location
FL
Ford's are not exempt... the diesel engines and some of the turbo EcoBoost have inherent problems to the point which you have to remove the top half of the engine, cab assembly or drop the engine for certain repairs...



I still am amazed "Service Position" on some cars is to remove the front cap and hoist the engine on its fenders. AKA: My Audi recommends doing it this way.
 

Eman

Member
Joined
Jul 10, 2025
Posts
62
Reaction score
20
Location
E Tennessee
Always start with the basics, how did this escalate to replacing the motor?
Did the FPS fix the problem of setting that code? What does the fuel pressure read? Compression test is where I start, eliminates doubt about engine condition somewhat. Ignition would be looked at, spark plug age and condition and the rest of the components. Fuel filter is a maintenance item when in doubt throw it out. You have the ability to read codes does it set a misfire code?
 

Kev555

Member
Joined
Dec 12, 2021
Posts
374
Reaction score
170
Location
Ireland
that´s why I LOVE Ford.. My wife has a 2007 Fiesta..with Duratec Engine .. "Bullitt- Proof "
German cars..or better all European Cars are junk in these days. Expensive.. and poorly engineered
I had a Ford connect with the 1.8 puma diesel engine, it was bulletproof compared to the wet belt rubbish they are churning out today.
 

MrBhp

Senior Member
Joined
Sep 12, 2013
Posts
1,778
Reaction score
1,500
He's busy repairing his parts cannon. It overheated.
 

Frankydanks

Junior Member
Joined
Sep 3, 2025
Posts
8
Reaction score
1
Location
Las Vegas
im going to stick through it and try to fix it, i will end up doing the motor refresh and pray for the best hoping my issue is fixed
My advice is fix your existing motor, especially if it still runs well and doesn't burn oil. At 185k miles you're long overdue for an engine refresh anyway and here's a shopping list of parts for you:

OEM VCT Solenoids: 8L3Z-6M280-B
Ford Performance Camshaft Drive Kit: M-6004-463V
Ford Performance Rocker Arm Lash Adjuster Kit: M-6529-3V
Felpro Timing Chain Tensioner Gasket Set: ES73226
OEM valve stem oil seals: 3L3Z-6571-DA (or Viton valve stem oil seals).
PQY Performance valve spring compressor: VSC07B
OEM '13-'14 Shelby GT500 high pressure oil pump (Ford part no. DR3Z6600A)
OEM 3V oil pump pickup tube (Ford part no. 4R3Z6622AA)
 

Latest posts

Support us!

Support Us - Become A Supporting Member Today!

Click Here For Details

Back
Top