Need help troubleshooting a possible EEC startup problem

manicmechanic007

Mustang Master
Sep 26, 2017
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Karthief,
I looked at a bunch of 87 (86-93) fuel rails online and ebay and not a one of them has a test port
Was kind of surprised
I guess the Shrader valve ones did not come around until 94 or maybe there are different rails for different markets
 
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manicmechanic007

Mustang Master
Sep 26, 2017
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Okay there you go
The port is on the line not the rail in that 2nd photo
Makes more sense
I do not remember having to get the adapters out to test fuel pressure much except the real early ones
 

JohnW63

Member
Jan 9, 2022
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Southern California
Visited the Mustang today. The funny thing was, when I looked at the picture after I posted it, the black pipe was in the shot, just not inserted at both ends. My memory of that night was there was no pipe. Turns out it had fallen loose and hidden in the snake of wire loom stuff. I found it and plugged it back in place. Started the car without pumping the gas at all. It fired up and then died maybe 5 seconds later. Did it again and after a few cranks it fired up at a reasonable idle speed. Once it ran for a minute or two, I shut it down and fired it up again. Just like old times, for this setup. I wish I had tried before installing the pipe, just to see if it coughed and bucked about it and then installed it and saw the difference. Either way, I'm going to let it sit until Sat, 3 more days and try again. Would this loose and then missing connection cause the nasty starting issue, or do I need to let it sit longer to see if that symptom comes back?

I do want to figure out the start and die and then restart issue. Now that I have this much time in the job, I want to make it right. That was why Dad spent the bucks for a new tank with the fuel pump lines in the normal spot for a 65 Mustang, at the front face of the tank, rather than the top , like a modern tank.

Clearly, with fuel lines connecting to the rails with AN style connectors, I won't be able to use a modern fuel line with fittings like General posted. I may have to have a male to female AN hose made with a Schrader valve in it as an adapter.

Oh and slightly off topic. When you goose the throttle for a quick burst, the cone shaped K&N air filter makes an sound like it sucks air and a flap closes. There is a slight delay between goosing the gas and the engine reving. The filter is at the end of the large hose leaving my picture at the left. There is a plug wired in and perhaps a sensor there. Looking at this shot I found online, this is the Mass Air Flow Sensor: #12. Just remove the air box and stick a cone paper filter on the end.
Tech_FBengine.jpg



You mentioned some questions about the distributor. My Dad has relocated the electronic module that is normally bolted to the distributor and attached it to the driver side fender. It was getting to hot in the normal spot or something. Where the air box is, in the above picture, is where the battery sits in the 65. That got relocated into the trunk. The engine was brand new from Ford with aluminum heads. One of the last ones left at the time, Dad tells me. ( I'll start a new thread with a question about the engine. )

Besides the two start issue, the only thing left to fix is that when it's idling, it doesn't hold a steady idle. It wavers by about 100rpm I would guess. Not troublesome, but enough to notice. We figure there may be a vacuum leak somewhere.
 

JohnW63

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Jan 9, 2022
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General,

The ones with the valve on them are not cheap, are they?

I forgot to ask, from above... what areas of the engine do you need close up pictures of to get a better date range? I looked on the block to find a date stamp, down by the starter and there was none. I suspect because it was never installed into a car at Ford. It was a replacement ,new in a crate, motor sold years after they came out.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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You may have to remove the starter to see a date code, not sure, as for the relocation of the tfi that would explain the distributor looking strange,
If the cone filter is attached to the maf that could make the idle 'hunt', try adding a pipe about 6" long between the filter and the maf, the reason is it straightens out the air before it goes through the maf. The air coming into the cone filter is turbulent and can make the maf readings erratic which makes the computer mad because it can't figure out what to do.
You can ask engine questions in this thread, members are following along and will be familiar with this build so you won't have to answer questions twice.
And yes, those regulators are pricey, I like the an hose adapter idea, look around the Summit catalogue, you may find some kind of solution there.
 

JohnW63

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Jan 9, 2022
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General,

I found the inline hose style for about 30 bucks. I would need to get a hose extension for my pressure gauge, so I wouldn't have to be under the car to read it. It wouldn't let me test the pressure on the other side of the pressure regulator however.

Is there another filter type we could install. The original box that is fed from a hole in the engine bay won't work. I'll have to take a picture of that area and measure the space. Obviously, I could remove the K&N for a minute and see if the idle hunting stops, as proof of diagnostic.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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You don't need exactly 6" , the idea is to give the air a chance to straighten out, I have a slight turn in my extension and I have a shield that hopefully helps with blocking engine heated air.
You have to picture the air moving, air does not like to turn, air entering a conical filter does so from all sides, put the filter close to the inner fender and the air from that side will be less than the opposite side, this uneven air pressure can cause the air to 'tumble' around ('turbulence ') before it can straighten out, having the filter mounted directly to the maf may not be allowing the air to smooth out before the meter making it not read consistently,
This is based on discussions with the people from a C&L meter tech way back when they were in business and the cartoon mind of a crazy man and not based on any real scientific research by me.
As for the fuel pressure gauge issue, I would want the gauge to be before or at the fuel rail, without putting hands on the vehicle I couldn't guess how to do it,
 

JohnW63

Member
Jan 9, 2022
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I did the SeaFoam treatment today and experimented with the air filter. With the cone filter in place, it would hunt a bit for the right idle speed. With it off, the idle speed was worse. It slowed down and the range of revs in the hunting was at least twice as wide. When it was still warming up, it would stumble if it goosed the gas. Once warm is was much better. Based on the smell and the dark soot in the exhaust tips, I think the car is running rich. I then thought opening the air flow would improve things. I was wrong.

We may have a source for a fuel rail with a valve on it, from our long time supply place. They have one. The guy on the phone thought it was from a 1989. We're waiting for the boss to call us and give a price. I took a shot of the fittings more close up. I think the custom fitting on the hose ends works with the stock quick connect type fuel lines rails. I'll get the picture off my wife's phone and post it.
 

manicmechanic007

Mustang Master
Sep 26, 2017
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Surging or hunting for idle is usually caused by a vacuum leak or any unmetered air getting to the engine
For instance if your intake gaskets leak and the O2 sensor goes lean
The processor sends fuel (increases the injector pulse width) That increases the idle speed
When the processor sees the increased idle speed and no change in TP voltage
it cuts the fuel flow making the idle drop
Then the cycle repeats
A real loose timing chain will sometimes mimic leaking intake gaskets or the MAF intake pipe
 

Blue_67Vert

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Sep 25, 2016
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Your set-up is similar to mine. I installed a '90 5.0HO in my '67. I'm using the Aeromotive Gen II Stealth tank with in-tank pump.

I had similar issues getting mine started. It ended up being 2 problems; first was fuel pressure. I found that my fuel filter was clogged. The problem came back a few times. I think I'm on my 3rd filter. It's been good for over a year now but I have a spare filter on my parts shelve just in case. I reused the original fuel line as my return which may been the source of crud in the lines.

The second problem was my fuel injectors. I had tested them prior to installing and thought they were good, but after many hours diagnosing I pulled them and found that more than a few were not good. There must've been some crud in the fuel rail Despite my best efforts to clean out them out. Out of 2 sets of used injectors I thought I had 8 good ones and used those. She ran but she didn't run right. I finally broke down and forked out the mulah for new injectors. She's been running awesome since.

Just to be clear, normally there are 2 extensions dropping down off the fuel rail and the fuel lines would connect to the those extensions. The stock shrader valve would be on the supply side extension. Your pic shows that you don't have those extension pieces.

http://www.veryuseful.com/mustang/tech/engine/ is a great source for online diagrams.

Ford Fuel Injection and Electronic Engine Control 1988-1993 by Charles Probst is another great resource to have. It explains every sensor in the system. I don't know what changes were made for '94.

Can you see the Code on the EEC-IV computer? It would be good to know exactly which one you're running.

Just don't give up. It took me a while to sort mine out. It's all worth it in the end. It may be frustrating but you're gaining a lot of knowledge and experience in the process. And you'll be more familiar with it all when the next problem arises.
 

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JohnW63

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The EEC unit we have is...

EEC-IV SF1-MA12A A9P
E9ZF-12A650-CA
61SM12AF03 43481-192 2F12

When I installed the tank, I installed a new fuel filter on the line headed to the front of the car. It's not a small coffee can style one, like my Dad had before. Just a small cylinder type. I don't know if there is another one hidden in the engine bay, but I don't think so.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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there is no point in spit balling till you can monitor a few things the computer can't. Starting with the fuel system, you need to install a gauge, one thing at a time, start changing too many things without verifying and you can miss a simple solution.
 
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General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
22,755
8,251
203
polk county florida
With those connectors you can install the stock fuel lines that run down the side of the engine and plug the aftermarket lines into those, you may have to get creative with the excess braided lines, maybe you can pull it beck at the tank, then you have the schrader valve for checking fuel pressure.
 

manicmechanic007

Mustang Master
Sep 26, 2017
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You could drill and tap the square block on the rail in the picture
Over the years when making pressure taps for cfi and the like
I used to go to the junkyard for parts.
The schrader valve fitting screws out of the rail in most Fords
I have the tap not sure of the size
I can look and see if needed
 

Blue_67Vert

Member
Sep 25, 2016
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The EEC unit we have is...

EEC-IV SF1-MA12A A9P
E9ZF-12A650-CA
61SM12AF03 43481-192 2F12

When I installed the tank, I installed a new fuel filter on the line headed to the front of the car. It's not a small coffee can style one, like my Dad had before. Just a small cylinder type. I don't know if there is another one hidden in the engine bay, but I don't think so.

According to this post A9P is 1989-92 AUTO. That could be useful info for future trouble-shootings you can reference the correct diagrams. And I'm going to recommend Ford Fuel Injection and Electronic Engine Control 1988-1993 by Charles Probst again as it covers your A9P.

My fuel filter was new at install too. Then it eventually got gunked up. I cleaned it and after some time it got gunked up again. Then the second. Point being, you really need to get that fuel pressure gauge attached as your next step.
 

manicmechanic007

Mustang Master
Sep 26, 2017
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Get a schrader valve installed so you can take a fuel sample easily
See just how much gunk is in the tank and lines