Notices
Texas Chapter Join Chapter, Leader: LibTimothy

North Austin/Round Rock - Looking for Ford Master Mechanic for EEC-IV & EGR troubleshooting

Thread Tools
 
Search this Thread
 
Old May 14, 2019 | 12:17 PM
  #1  
CZ Eddie's Avatar
CZ Eddie
Thread Starter
|
Mountain Pass
5 Year Member
Liked
Joined: May 2018
Posts: 165
Likes: 2
North Austin/Round Rock - Looking for Ford Master Mechanic for EEC-IV & EGR troubleshooting

Round Rock/North Austin: Anyone know of a Ford Master Mechanic who won't just replace parts you've already replaced.
And will actually listen to the troubleshooting steps you've already taken?
And knows mid 90's EEC-IV & EGR system like the back of their hand?

As you can see below, I've already done a LOT of t/s on my own and need someone who will pay attention to that and not just start from scratch.

------------

Code 172 & 334.
I suspect the 172 is just a symptom of the code 334.


  • 1994 Bronco
  • 5.8L Windsor
  • E40D auto
  • 192k miles
  • No mods that I know of.
  • Just bought it from a car lot a few weeks ago, issue has been present from day one.


    Symptoms I get:

    Runs smooth till it warms up.
    Then when I stop at a light, the idle might suddenly drop from ~1k down to ~500 RPM and stumble.
    Then pop back up to ~1k for a moment, then drop to ~500 again. And occasionally dies.
    When this happens, sometimes the tranny will suddenly start shifting at really high RPM's with whiplash effect.


    Things I've replaced in the last two weeks:

    -EGR Vacuum Regulator Solenoid
    -Coolant Temperature Sensor
    -Idle Air Control Valve
    -Throttle Position Sensor
    -Fuel Pressure Regulator
    -ACCEL Supercoil
    -ACCEL Distributor Cap
    -Ford Racing Spark Plug Set
    -02 Sensor
    -EGR Valve Position Sensor
    -Replaced all vacuum hoses
    -Cleaned PCV Valve
    -Cleaned Throttle Body


    Troubleshooting steps I've taken so far:

    -Plugged Vacuum tester into EVR top line going to EGR and it held vacuum.
    -Plugged Vacuum tester into EVR bottom line going to solenoids and it held vacuum.
    -Applied vacuum to EGR while engine was running and the diagphram moved and engine idle changed.
    -EVR 12V pin shows -12V on my multimeter.
    -Shorted EVR's pin 33 to ground while engine running and the engine died.
    -Applied vacuum to vacuum cannister AMP with MAN disconnected. It holds vacuum fine.
    -When I do the KOER code test, the EGR does not move.
    -Hooking a vacuum guage inline with cannister AMP shows "green" levels of vacuum (good).
    -EVP shows 5v at pins VREF and SIG RTN.
    -EVP shows ~3700 ohms at pins VREF and EVP and it goes down to ~350 when I apply 10hg vacuum to EGR.
    -Disconnected IAC. Applied vacuum to EGR and engine RPM's stumbled as expected.
    -Put Vacuum tester inline at EGR and raised engine RPM's, the vacuum does not register anything at all.

    I'm sure I've forgotten a few things.
    Any and all help would be appreciated!
    If there are any sensors I should try replacing, then I can do that too.
  • E40D auto
  • 192k miles
  • No mods that I know of.
  • Just bought it from a car lot a few weeks ago, issue has been present from day one.

Symptoms I get:

Runs smooth till it warms up.
Then when I stop at a light, the idle might suddenly drop from ~1k down to ~500 RPM and stumble.
Then pop back up to ~1k for a moment, then drop to ~500 again. And occasionally dies.
When this happens, sometimes the tranny will suddenly start shifting at really high RPM's with whiplash effect.


Things I've replaced in the last two weeks:

-EGR Vacuum Regulator Solenoid
-Coolant Temperature Sensor
-Idle Air Control Valve
-Throttle Position Sensor
-Fuel Pressure Regulator
-ACCEL Supercoil
-ACCEL Distributor Cap
-Ford Racing Spark Plug Set
-02 Sensor
-EGR Valve Position Sensor
-Replaced all vacuum hoses
-Cleaned PCV Valve
-Cleaned Throttle Body


Troubleshooting steps I've taken so far:

-Plugged Vacuum tester into EVR top line going to EGR and it held vacuum.
-Plugged Vacuum tester into EVR bottom line going to solenoids and it held vacuum.
-Applied vacuum to EGR while engine was running and the diagphram moved and engine idle changed.
-EVR 12V pin shows -12V on my multimeter.
-Shorted EVR's pin 33 to ground while engine running and the engine died.
-Applied vacuum to vacuum cannister AMP with MAN disconnected. It holds vacuum fine.
-When I do the KOER code test, the EGR does not move.
-Hooking a vacuum guage inline with cannister AMP shows "green" levels of vacuum (good).
-EVP shows 5v at pins VREF and SIG RTN.
-EVP shows ~3700 ohms at pins VREF and EVP and it goes down to ~350 when I apply 10hg vacuum to EGR.
-Disconnected IAC. Applied vacuum to EGR and engine RPM's stumbled as expected.
-Put Vacuum tester inline at EGR and raised engine RPM's, the vacuum does not register anything at all.

I'm sure I've forgotten a few things.
Any and all help would be appreciated!
If there are any sensors I should try replacing, then I can do that too.
 
Reply
Old May 15, 2019 | 09:26 PM
  #2  
CZ Eddie's Avatar
CZ Eddie
Thread Starter
|
Mountain Pass
5 Year Member
Liked
Joined: May 2018
Posts: 165
Likes: 2
Nevermind, I fixed it

https://www.fullsizebronco.com/forum...-expected.html
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Gnnut
1983 - 2012 Ranger & B-Series
21
Jul 18, 2012 09:24 PM
whateg01
1987 - 1996 F150 & Larger F-Series Trucks
6
Aug 27, 2007 09:48 AM
puck1263
1987 - 1996 F150 & Larger F-Series Trucks
34
Nov 10, 2005 06:02 PM
yosemite
1978 - 1996 Big Bronco
4
Oct 23, 2002 07:51 AM
rusty9
1987 - 1996 F150 & Larger F-Series Trucks
4
Jun 11, 2002 11:42 AM




All times are GMT -5. The time now is 05:41 AM.

story-0
10 Things Every Truck Owner NEEDS (2026 Edition)

Slideshow: the best gifts for dads & grads

By Michael S. Palmer | 2026-06-02 21:45:57


VIEW MORE
story-1
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath

Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.

By Verdad Gallardo | 2026-05-30 18:33:59


VIEW MORE
story-2
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer

Slideshow: 10 most expensive Ford trucks ever sold on Bring a Trailer.

By Joe Kucinski | 2026-05-27 16:24:34


VIEW MORE
story-3
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)

Here's everything that has changed for the latest model year.

By Brett Foote | 2026-05-27 16:17:28


VIEW MORE
story-4
Top 10 Ford Truck Tragedies

Slideshow: Top 10 Ford truck tragedies.

By Joe Kucinski | 2026-05-18 19:34:33


VIEW MORE
story-5
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make

And it might be even better than that.

By Brett Foote | 2026-05-18 19:26:42


VIEW MORE
story-6
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!

Slideshow: Does lowering an F-150 Lobo RUIN the ride quality?

By Michael S. Palmer | 2026-05-18 19:20:37


VIEW MORE
story-7
Ford's 2001 Explorer Sportsman Concept Looks For a New Home

Slideshow: Ford's bizarre fishing-themed Explorer concept has resurfaced after spending decades largely forgotten.

By Verdad Gallardo | 2026-05-12 18:07:46


VIEW MORE
story-8
10 Best Ford Truck Engines We Miss the Most!

Slideshow: The 10 best Ford truck engines we miss the most.

By Joe Kucinski | 2026-05-12 13:09:47


VIEW MORE
story-9
2026 Shelby F-150 Off-Road: Better Than a Raptor R?

Slideshow: first look at the 810 hp 2026 Shelby F-150 Off-Road!

By Brett Foote | 2026-05-12 12:50:07


VIEW MORE