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Check Engine Light Issues..

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Old Feb 14, 2021 | 11:35 AM
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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
 
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Old Feb 15, 2021 | 08:59 AM
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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)?

 
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Old Feb 15, 2021 | 09:19 AM
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Originally Posted by rla2005
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)?
They were pulled from the computer with a Snap on scanner.Had the shop pull them before battery was disconnected before timing chain replacement last week.
They were all 2 digit codes.Which I have already looked up and it all related to EGR System
 
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Old Feb 15, 2021 | 09:39 AM
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Originally Posted by Kenneth P
They were pulled from the computer with a Snap on scanner
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.


Originally Posted by Kenneth P
They were all 2 digit codes.Which I have already looked up and it all related to EGR System
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.
 
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Old Feb 15, 2021 | 09:50 AM
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Originally Posted by rla2005
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.
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.
 
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Old Feb 15, 2021 | 10:10 AM
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test it before you start throwing parts at it
Ford Fuel Injection » EGR Vacuum Regulator (EVR)
 
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Old Feb 15, 2021 | 10:13 AM
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Originally Posted by Kenneth P
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.
Originally Posted by torq'ta 5 8
test it before you start throwing parts at it
Ford Fuel Injection » EGR Vacuum Regulator (EVR)
Planning on it for sure..Crazy that it's running perfect and codes dropping..Just believe it's a electrical issue..
 
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Old Feb 15, 2021 | 10:19 AM
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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.
 
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Old Feb 20, 2021 | 10:37 AM
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Originally Posted by rla2005
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.
Unplugged EVR and tested resistance with meter..Got 000 .So I'm guessing it's no good
 
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Old Feb 20, 2021 | 10:53 AM
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Originally Posted by rla2005
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.
Unplugged EVR and tested resistance with meter..Got 000 .So I'm guessing it's no good
 
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Old Feb 20, 2021 | 06:37 PM
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Originally Posted by Kenneth P
Unplugged EVR and tested resistance with meter..Got 000 .So I'm guessing it's no good
Based on the resistance values I posted I would agree the EVR is bad.
 
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Old Feb 20, 2021 | 06:43 PM
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Originally Posted by rla2005
Based on the resistance values I posted I would agree the EVR is bad.
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??
 
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Old Feb 21, 2021 | 05:45 AM
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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
 
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Old Feb 21, 2021 | 11:21 AM
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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.
 
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Old Feb 21, 2021 | 03:56 PM
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I was pretty confident a new EVR would fix most of your issues. Thanks for the reply back.
 
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