Check Engine Light Issues..
Thread Starter
|
Freshman User
Joined: Feb 2021
Posts: 33
Likes: 0
Check Engine Light Issues..
Got a 93 F150 5.0 ..Throwing a 33,81,84,85.Truck runs good with no stalling,no rough idle.I'm lost..Light will come on after it warms up and heading down the road.It will come on and go off.Seems to be staying on longer now All vacuum lines are covered and in good shape.Where should I start.I have looked up all the codes and to me it is all related to EGR.EGR valve is the only thing that has been replaced and that's the only thing that has been replaced.It was replaced before I got truck
Fleet Owner
Joined: Oct 2005
Posts: 20,780
Likes: 1,746
From: Kentucky
A 1993 model year truck could display 3 digit codes instead of 2 digit codes. How did you pull the codes? Count flashes or use a code reader?
When were the codes displayed? Key On Engine Off (KOEO), Continuous Memory (CM) or Key On Engine Running (KOER)?
When were the codes displayed? Key On Engine Off (KOEO), Continuous Memory (CM) or Key On Engine Running (KOER)?
Thread Starter
|
Freshman User
Joined: Feb 2021
Posts: 33
Likes: 0
They were all 2 digit codes.Which I have already looked up and it all related to EGR System
Fleet Owner
Joined: Oct 2005
Posts: 20,780
Likes: 1,746
From: Kentucky
Thanks for confirming. As I stated before your truck could display 2 or 3 digit codes. No sense going down the wrong bunny hole...which happens frequently when folks use the count flashes method.
Not all of the codes are EGR related. Code 81 has two different definitions. Code 81 (KOEO) Air management 2 circuit failure (AM2/TAD). Code 81 (CM) MAP sensor vacuum was not greater than 2 in-Hg (7 kPa) during normal vehicle operation. That is the reason why we need to know when the codes were displayed.
Code 85 KOEO & KOER: Canister Purge Solenoid circuit failure. This has nothing to do with the EGR system.
Code 33 and Code 84 are EGR related. Code 84 KOEO & KOER: EGR Vacuum Solenoid circuit failure. Code 33 CM: EGR valve opening not detected during engine operation. Code 33 KOER: EGR valve opening not detected during the KOER tests.
Code 84 is most likely causing Code 33 since Code 84 indicates an electrical issue with the EVR solenoid. It may be physically disconnected.
Code 85 KOEO & KOER: Canister Purge Solenoid circuit failure. This has nothing to do with the EGR system.
Code 33 and Code 84 are EGR related. Code 84 KOEO & KOER: EGR Vacuum Solenoid circuit failure. Code 33 CM: EGR valve opening not detected during engine operation. Code 33 KOER: EGR valve opening not detected during the KOER tests.
Code 84 is most likely causing Code 33 since Code 84 indicates an electrical issue with the EVR solenoid. It may be physically disconnected.
Thread Starter
|
Freshman User
Joined: Feb 2021
Posts: 33
Likes: 0
Thanks for confirming. As I stated before your truck could display 2 or 3 digit codes. No sense going down the wrong bunny hole...which happens frequently when folks use the count flashes method.
Not all of the codes are EGR related. Code 81 has two different definitions. Code 81 (KOEO) Air management 2 circuit failure (AM2/TAD). Code 81 (CM) MAP sensor vacuum was not greater than 2 in-Hg (7 kPa) during normal vehicle operation. That is the reason why we need to know when the codes were displayed.
Code 85 KOEO & KOER: Canister Purge Solenoid circuit failure. This has nothing to do with the EGR system.
Code 33 and Code 84 are EGR related. Code 84 KOEO & KOER: EGR Vacuum Solenoid circuit failure. Code 33 CM: EGR valve opening not detected during engine operation. Code 33 KOER: EGR valve opening not detected during the KOER tests.
Code 84 is most likely causing Code 33 since Code 84 indicates an electrical issue with the EVR solenoid. It may be physically disconnected.
Not all of the codes are EGR related. Code 81 has two different definitions. Code 81 (KOEO) Air management 2 circuit failure (AM2/TAD). Code 81 (CM) MAP sensor vacuum was not greater than 2 in-Hg (7 kPa) during normal vehicle operation. That is the reason why we need to know when the codes were displayed.
Code 85 KOEO & KOER: Canister Purge Solenoid circuit failure. This has nothing to do with the EGR system.
Code 33 and Code 84 are EGR related. Code 84 KOEO & KOER: EGR Vacuum Solenoid circuit failure. Code 33 CM: EGR valve opening not detected during engine operation. Code 33 KOER: EGR valve opening not detected during the KOER tests.
Code 84 is most likely causing Code 33 since Code 84 indicates an electrical issue with the EVR solenoid. It may be physically disconnected.
Lead Driver
Joined: Jan 2019
Posts: 5,063
Likes: 860
From: N.W. Alabama
Thread Starter
|
Freshman User
Joined: Feb 2021
Posts: 33
Likes: 0
EVerything is plugged up and after doing some studying .Believe I will start by replacing EVR solenoid.Which if I read right triggers the EGR..Truck runs smooth at all times.No issues at all.I'm figuring it's electrical.Everything is factory and never been replaced except EGR Valve..Truck was my grandfather's since basically new.He bought it with 50,000 miles from Ford Dealer which the truck was his neighbors.
test it before you start throwing parts at it
Ford Fuel Injection » EGR Vacuum Regulator (EVR)
Ford Fuel Injection » EGR Vacuum Regulator (EVR)
Trending Topics
Fleet Owner
Joined: Oct 2005
Posts: 20,780
Likes: 1,746
From: Kentucky
If the EGR Valve Regulator (EVR) is plugged in it could have an open coil or the connection is bad. You can measure the coil resistance with a meter. Should be ~ 20-70 ohms.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Thread Starter
|
Freshman User
Joined: Feb 2021
Posts: 33
Likes: 0
Unplugged EVR and tested resistance with meter..Got 000 .So I'm guessing it's no good
Thread Starter
|
Freshman User
Joined: Feb 2021
Posts: 33
Likes: 0
Thread Starter
|
Freshman User
Joined: Feb 2021
Posts: 33
Likes: 0
Ordered a new one and will get tomorrow.Then onto EGR position sensor.Which I feel that EVR is giving the problem.Also,I need to check other sensor's.Do you still look for the same resistance??
Lead Driver
Joined: Jan 2019
Posts: 5,063
Likes: 860
From: N.W. Alabama
It will vary, The EVP is a Linear Potentiometer which uses variable resistance to provide the EEC with a voltage signal indicating the position of the EGR Valve Pintle.
here is test-->EGR Valve Position (EVP) Sensor Testing & Replacement | Bronco Forum - Full Size Ford Bronco Forum
here is test-->EGR Valve Position (EVP) Sensor Testing & Replacement | Bronco Forum - Full Size Ford Bronco Forum
Thread Starter
|
Freshman User
Joined: Feb 2021
Posts: 33
Likes: 0
EVR replaced and computer reset.No check engine light and no trying to cutoff on me this morning when coming to stop sign.Did notice that cold idle did come down faster at crank up.The vacuum valve was definitely stuck on the old one.Had a feeling that this was causing all my other codes down stream.Thank You all that replyed.