Need help troubleshooting a possible EEC startup problem

Last week I was wiggling stuff while it was running and thought moving the MAF plug did make a change so I sprayed it pretty well with electronic contact cleaner, blew it out with compressed air and plugged and unplugged it a few times.

We don't have a canister, so I am not sure we have a purge line still in the mix.

There doesn't look to be many vacuum lines to be honest. One from the passenger valve cover to the throttle body is one I know of and I made a new hose for that.
 

Willybill32

But at least it's tight!
Jul 16, 2019
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Last week I was wiggling stuff while it was running and thought moving the MAF plug did make a change so I sprayed it pretty well with electronic contact cleaner, blew it out with compressed air and plugged and unplugged it a few times.

We don't have a canister, so I am not sure we have a purge line still in the mix.

There doesn't look to be many vacuum lines to be honest. One from the passenger valve cover to the throttle body is one I know of and I made a new hose for that.
Technically, the line from the oil fill tube to the throttle body isn’t a vacuum line, but an emissions hose to route oil vapor into the intake manifold. That shouldn’t affect running behavior. I’ll attach a picture showing the vacuum lines.
 

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I haven't pulled the intake, but I've determined, by feel and flashlight that I only have the large line to a power brake booster and a small line to the Fuel Pressure Regulator. The large hose at the front looks in good condition and moving it as much as I can does not change the idle. Doing the same at the back where the lines come out also has no affect. I starting messing with the MAF sensor and air filter. Removing the air filter didn't change much. Then I pulled the connector to the MAF sensor and nothing really changed. I cleaned it with contact cleaner with no improvement. I cleaned the MAF with special MAF cleaner, during the earlier I then pulled the MAF connector and it didn't change that I could tell. It makes me wonder if that is at least part of the issue.
 
I know it's been quite some time since I updated this thread but parts were ordered and replaced and tests made.

Because of the MAF sensor error , I replaced the sensor with a Delphi one. Right off the car didn't die after a few seconds but did die a bit longer along when the idle speed just got to low. By starting it again and using a finger on the throttle cable I could keep it running. The car has the little Ford plate to go between the air flow bypass unit and the throttle body. I was able to wind out the the top set screw a bit to get the idle at about 650rpm and it stayed there. After a week, of no running, the car started up and did not die at all . I think there is progress.

Where it still has an issue is at the first touch of throttle, it does stumble and then rev fine. This may only be under getting the car warmed up. I ran the codes the previous week, when I installed the MAF sensor and I had the EGR codes ( which we don't have an EGR ) and the codes air diverter, I believe.

I also ran the car without the Ford idle plate and the idle was just a bit higher and may have hunted a bit.

I checked the timing today, and at idle, it was in the mid 20s and when I reved it , it went past 30 degrees. I suspect that is normal, but it would be nice to be sure.

Any thoughts on what the next test should be?
 

jrichker

StangNet's favorite TOOL
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I'll have to scroll back up the this thread to see, but that sounds familiar.
You guys with idle/stall problems could save a lot of time chasing your tails if you would go through the Surging Idle Checklist. Over 50 different people contributed information to it. The first two posts have all the fixes, and steps through the how to find and fix your idle problems without spending a lot of time and money. It includes how to dump the computer codes quickly and simply as one of the first steps. I continue to update it as more people post fixes or ask questions. You can post questions to that sticky and have your name and idle problem recognized. The guys with original problems and fixes get their posts added to the main fix. :D

It's free, I don't get anything for the use of it except knowing I helped a fellow Mustang enthusiast with his car. At last check, it had more than 250,000 hits, which indicates it does help fix idle problems quickly and inexpensively.
 

manicmechanic007

Mustang Master
Sep 26, 2017
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Ford puts out the diagnostic sub routines
You think yours is better?
I have no need for aftermarket information
Is the NGS in there and breakout box diagnosis?
Pinpoint tests from the H manual in there?
How many pages is this wonderful checklist?
 

General karthief

wonder how much it would cost to ship you a pair
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Aug 25, 2016
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Ford puts out the diagnostic sub routines
You think yours is better?
I have no need for aftermarket information
Is the NGS in there and breakout box diagnosis?
Pinpoint tests from the H manual in there?
How many pages is this wonderful checklist?
here you go again!
how many members here have a breakout box?
how many here know what that or NGS is?
The checklist was designed for the DIY guy (or gal) to find and fix their mustang (it can work with other models too) with simple tools and limited mechanical experience. Not many here have ASC or Ford Factory Certification patches on their sleeve and a room full of diagnostic equipment to work with, if they did they would not be here try'n to get tips and tricks on how to get their stang running like it should so they can possibly embarrass a few brand x drivers out on the highways.
I will defend the checklists and the members that helped put it together to the limits of the interwebs.
As a member of Stangnet.com you should support our members contributions or go to facepage where you can join in on the keyboard cowboys show
If you have a rebuttal we can continue this in a more appropriate forum like Derailers Anonymous or The Feedback Zone.
 
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