85 Convertible

[Mrsneve]

I have a 1985 Mustang 5.0 Convertible with 46,900 miles on it. Long block was replaced at 26,000 miles. It has the fuel injection system that looks like a throttle body with two injectors. PROBLEM: When the engine reaches normal operating temp (after about 5 miles of driving) the car starts to chug and if I slow down and stop, it dies. Starts back up no problem, but will die if I slow down under about 15mph. Previously, it would jump to over 2000 rpm after warming up. I replaced the idle control module and that problem went away. I just replaced the catalytic converter, which was totally shot, both mufflers and the tailpipes hoping the chugging was a catalytic convertor problem. No luck. Any suggestions? What do I do now? Any and all suggestions would be appreciated. I would like to drive it before the weather prohibits it.

[boboli]

I have no personal experience on this type of car but if you search for "CFI issues", I know there have been several people with similar problems over the last year. One reoccurring problem on that system seems to be vacuum leaks. Try scanning for codes as well. Good luck

[JACook]

Start by pulling KOEO and KOER codes. The CFI system uses the same procedure as the later SEFI cars,
though the code definitions differ somewhat. I would also hang a fuel pressure gauge on it, and a timing
light.

CFI systems are very picky about three things -

Fuel pressure. The spec is 39 PSI ± 2 PSI. Usually 40-41 is the sweet spot.

MAP sensor vacuum signal. Make sure the vacuum hose to the MAP sensor has no cracks or kinks, and
that the hose connects directly from the manifold vacuum tree to the MAP sensor, with nothing else tee'd
into it. Also make sure the MAP sensor itself doesn't leak.

Ignition timing. Apart from the vacuum kick-up, the idle speed control on the CFI 5.0 is done by varying
the ignition timing. The timing needs to be set to 10º BTDC with the SPOUT connector unplugged. You
may also want to verify the outer ring on the crank damper hasn't shifted, since that's a very common
problem. If it has, your timing will be incorrect, and that will really mess with the CFI's mind.

[Mrsneve]

Thanks for the input. Where do I get the codes? There is no hookup under the dash on an 85.

[erratic50]

The other thought - might it be a spark or ground problem?

[KevinK]

I believe the code retrieval port is under the hood by the master cylinder as they were for the eec-4 system. Pretty sure an OBD scanner will not work

[xctasy]

I believe the code retrieval port is under the hood by the master cylinder as they were for the eec-4 system. Pretty sure an OBD scanner will not work

Kevin K is right that a lot of the later OBD Scanners won't work, but an Equus Innova 3145, and whatever the 3149 six foot chord is, sure does with the EECIV system on all CFi 5.0 85 Convertables.

It's just like the old Star/Rotunda/ Arcon reader Ford designed in the late 70's. Only odd balls for 85 were the 5.0 EECIII's, not found on the small Foxes, just the Sterling built S shell Foxes. The 3.8 V6, depending on where it was sold, might have another system, CFi or carb, but those were able to be broken out by Equus Innova 3145/ 3149.


Our on board anti Hero is Haystack.

Codes only require a jumper. The code reader is nothing more then a box thst flashes a light or beeps at you. Every test that can be performed can be done with a paper clip and a test light or analog meter.

https://youtu.be/z0ehA8cFTkc
https://youtu.be/9QSiS6wf7oU

Here i am running the test for a guy on another forum who couldn't figure it out.

Just the old sweep needle and cell phone will show all the codes for all the EECIV Mustang or Capri 5.0 Central Fuel Injection. A lot of people think the EECIV Mustang/Capri 5.0 central point Electronic Fuel Injection won't pull codes. It does. Its just missing some Keep Alive Memory function, but its essentially a full fettled EECIV.


Now, its it was the really bizzare EECIII Thunderbird or XR7 Cougar 5.0 Central Fuel Injection for California or High Altitide States, then that was just as Kevin K suggested, but there was actually a non publicised "work around" on that freeky little mudder too. They had a differnent voltage out put and it made it rather difficult/tricky/complicated

"Reading EEC-III Trouble Codes on a 1984 Ford Thunderbird"
Published by on crossalchemist 17 Jun 2011
https://www.youtube.com/watch?v=8WlOIsW1KlA



"1982 Ford EEC-III code reading"
Jul 23, 2012 - Uploaded by cnagorka https://www.youtube.com/watch?v=puAEJ3BYFeY

Note that after we filmed this I actually discovered an EEC test connector right by the pair of solenoids shown in the video. The connector is not mentioned anywhere in the tech

It was extensively discussed by Ford Technicians back in 1981 to 1982...Ford retrospectively transferred some out ball EECIII coding over to the EECIV, and the even EECIII can be read in a similar manner. The whole set-up for your CFi 5.0 is really easy to test.



In fact, the CFi EECIV is WAY more smarter than you'd ever believe. Ford dithered terriably over the exact kind of system used for the Thunderbird 5.0 CFi, right up till 1985, some versions were still EECIII with the darned BMAP sensor, but it also had another kind of access point from 1982 onwards.

This is why you might not need a 3145 Innova and 3149 cable....a good car guy can just use a sweep meter, and your good to go.




For anyone else,


I love EEK!Four. Its got multiple "issues", but once you use the book, it will give you a boat load of 1000% Helpfull data trouble codes to cross check. Its a flAg system.....you don't want to miss a trick, so spend 30 buxs on the 3145, and whatever the 3149 six foot chord is.

Now, before 1987, all MCU or EECIII or EECIV's didn't use the Malfunction Indicator Light as a Check Engine Light.

What lookes like an OSIO "oh sh!+ its oil" light is hard wired to flash.

Some used the "Engine" light to perform the same function as a "Check Engine Light". It just doesn't flash of operate like the traditional CEL light, but you can count flashes if its jumpered with the old six port to earth spade mouth connector.


Some early Fords even in the EECII, EECIII and MCU era even allowed you to use what looks like just an oil pressure light, but Ford was very shifty on the early pre 1982 and 1980 on cars, and the EVTM books were retrorespectivley editied and the base version had the references to MIL info (Malfunction Indicator Light as a Check Engine Light) removed. You found it only in some 1984-1985 Propane Technical Service Bulletins, and its obscure.

The 3145/3149 combo is a modern incarantion of the old Star/Arctron logger.




My recomendation,











The least helpfull EECIV system, the carb 1-bbl YFA feedback trucks, become easy reads with this system. An 83 to 86 Mustang with EEICIV, its a cinch.

https://www.youtube.com/watch?v=7o_YLw2b5co

it forces you to dig deep, so the reader with an extension chord eliminates the hassle.

https://www.youtube.com/watch?v=-YYQKssOEOs

There are three levels of checks, High level is the chip.

Low level is Digital code reader, which is needed for quick on the fly fault code checks because the 83 to 86 MCU/EFI Ford 2.3/3.8/5.0 Mustangs have no traditional CEL (Check Engine Light) or MIL (Mailfunction Indicator Lamp).

Intermediate level is a check done in the olden days using a Thexton 60 pin breakout box. (see pictures below, its a 6 x 10 matrix prong system, with an overlay for the various codes)


One or two you can do. And they won't blow up your computer or put you into the poorhouse...

.....

Your basic problems are easily found with a pre OBDII EECIV through a Code Reader Innova or Equus #3145 Code Reader with #3149 6FT CABLE.

That gives you a Dealer Trouble Code.

https://www.youtube.com/watch?v=XmOgURm7iXI



The third mode, aside from KOEO and KEOR test's, is a recording mode when running via a six foot cable that works the KAM (Keep Alive memory). I'd suggest that thats what you should do ASAP. .

[Mrsneve]

I replaced the plugs, plug wires, rotor, and distributor cap. Then set the timing by ear. It runs so much better than ever before, but I think I will replace the MAP vacuum hose just because.