Poor FL boy needs help getting his only vehicle running :)

ford
mustang

#1

It did this funny thing about 4-5 times over a span of about 24 hrs before dying and then won’t start. It was like hitting the limit on a speed governed car…sudden momentary loss of power…and it seemed to be when accelerating if that matters. The thing I’m sure of at this point is that the fuel pump is not coming on when the key is turned, I know that sound well, but also checked it at the external connector with a test light for thoroughness. I also found a blown fuse under the hood which coincided with a little smokey smell inside the car when the fuse was replaced and blew again. There is no spark as well. My Haynes book says that the PCM is behind the passenger kickpanel but I only see the eecv and it doesn’t smell burnt. The IFS is good. There is power at the coil packs. Fuel pump relay fuse is good. Is it more likely the ccrm since it contains the fuel pump relay and PCM relay or could it still be the eecv? Any professional help would be greatly appreciated. It feels like one part failed but is causing more than one “problem”, no power to fuel pump and no spark.


#2

Ford has been building Mustangs for a long time.

How old is yours? Which engine does it have? Is it manual or automatic?

Which fuse blew? Did it make any difference when you replaced the fuse?

It’s like pulling teeth.


#3

It’s a 96 convertible gt…4.6 liter 5speed…it was the EEC fuse that was blown and blew again when I replaced it during troubleshooting…that’s when I got the smoke smell…now the new fuse doesn’t blow…I ran power and grnd to the fuel pump and it 100% for sure works. Whatever died killed the spark signal to the coils and shut off power to the fuel pump…


#4

And I will give up a few teeth to get it running…cuz I love my car and mashed potatoes…lol


#5

Maybe this link will help. http://www.veryuseful.com/mustang/tech/engine/EECIVInnerWorkings.pdf
I would clean the MAF sensor before I did anything else.


#6

Well I’m not a mechanic but seems to me you found your problem. If the EEC is the same as ECM (engine control module or computer) which I believe it is, it controls spark and pump operation. If it is shot which it sounds like it is or else the wiring to it, you won’t get any spark, and the pump will not be signaled to turn on. I think you need to have the computer checked out or go to the junk yard and get one. If it is like GM though, you need to match the numbers on the computer, plus it has a plug in PROM that needs to be swapped from one to the other, provided that didn’t get fried too.


#7

Before deciding anything is bad I would first try to find out what the blown fuse supplies power to and what is the source of the short. Finding out those things may just solve the troubles.


#8

Man thanks…that helps alot knowing how it works and what it controls:)


#9

After reading the info on the link kizwiki sent…I think ur right on both accnts…the problem and the numbers matching…thanks everybody, as soon as I get more info to give or if its not fixed I’ll be back to update


#10

WHOA WHOA WHOA…if you swapped a blown fuse and then the new one snapped accompanied with a “smokey” smell in the car YOU HAVE A SHORTED WIRE…FORGET TROUBLESHOOTIN ANY FURTHER UNTIL YOU FIND THAT SMOKEY SMELLING WIRE…

All further attemps at diagnosis are stymied at this point until you find the short…NOTHING will operate properly with a shorted wire ANYWHERE in your car… FORGET EVERYTHING ELSE AT THIS POINT IN TIME YOU MUST MUST MUST FIND THAT SHORT… Then we can go further in troubleshooting…


#11

Ok, I guess I assumed the EEC or wire to it just burned the rest of the way when the replacement blew…i think it says in the manual what else it supplies power too but wouldn’t it almost have to be a wire to the EEC? Regardless I’ll see what I can find out short wise. Thanks


#12

There should be nothing else on the ECM circuit. If you fried the computer, it would blow the fuse or if you have a short in the wiring for it, it would blow the fuse. You can find the shorted wire and repair it but if the fried computer caused the wire to melt, just fixing the wire won’t solve the problem. Of couse there is always the chance that a wire rubbed together, causing the short in the first place but those wires really don’t move around much.


#13

I’m new here and just wanna say thanks again for the help to everyone…I just spent an hour or so under the hood, dash and down in the floor boards and can’t see any signs of a burnt wire. I tried to remove the three connectors infront of the eecv to get to it’s plug with a test light and was hoping to be able to find power or not but had alot of trouble trying to get the harness disconnected. So no dice. Back to the drawing board…


#14

Did clean the sensor btw…


#15

You’re welcome for the help. Hang in there we should be able to help you find the trouble.

Looking at some data it shows the EEC fuse also supplies power through some relay contacts on the PCM relay. The relay is located in the Constant Control Relay Module which may be under the hood. There appears to be 6 relays in there. Try pulling the PCM relay out and then see if the fuse blows out. If it doesn’t then the short is on the relay power circuit to the PCM. If it still blows then disconnect the EEC and see if the fuse blows then. If not then the EEC has a short to ground inside it.


#16

Thank u…I’m back out here again finally to work on it…I have the eecv removed…i can see and smell inside and seems fine. :frowning: I’m working on pulling the ccrm…what a pain…I’ll update with what I find…thanks again. Do you know which wire feeds the eecv power so I could check it at the plug which would tell me if that wire is good etc…?


#17

Holy ----! Man I can’t thank everyone enough for all the help whether it panned out or not…it’s nice to know that help is available even when the money is not. I haven’t opened the ccrm yet but my nose tells me I have found the problem…special thanks to cougar :slight_smile: I can’t wait to hear my baby purr again…


#18

The fuel pump may not be turning on because the the ignition system isn’t working. Can you hear the pump run when you turn the ignition switch from OFF to ON? If so, then the pump circuit is most likely ok.

I assume the EECv is the same thing as the PCM and if so power comes from the EEC fuse on a yellow wire to pin 55 of the PCM.

You’re welcome for the help on this and it’s nice to hear you really appreciate it. There are a number of helpful folks here on this site.


#19

Ok…I’m back…after replacing the ccrm and pretty sure it was the PCM relay that was bad inside by way of sniffer lol…still won’t start so I may still have a bad wire…can you tell me which wire should be hot to the ccrm? If it’s hot the wire is good and the problem is elsewhere and if it’s not…well I can just run a new power wire to it from the ignition side of things right?


#20

Power from the EEC fuse ties to the CCRM board with yellow wires on pins 8 and 10. Those pins tie to the PCM relay and the switched side of the relay ties to red wires on pins 12 and 24 of the same board to supply power to other areas. It also supplies power to the other relays on the board for either the coils or the switched contacts. The drawing is pretty complicated and would be too hard to go over like this. I think you are going to find that the shorting problem was due to something else besides the relay. I highly recommend you get a factory service manual, for the wiring at least, to help you with this trouble. There are a number of places the trouble can be coming from. You should also be able to get some info from your local library. If they have access to EBSCO Host or ALLDATA you can download the wiring info and print it out. Ebay is a good source for manuals also. A factory service manual is practically priceless in helping solve these kind of problems.

The red supply wires tie to a number of places like PCM pin 97, the purge solenoid, MAF sensor, and the injectors so there is a good chance the trouble is with one of those things or the wiring to them. There are a couple of solid state relays on the CCRM board for the EDF relay control and A/C clutch control so I suppose they could be a possible suspect.

On the simple side of this, check the wiring under the hood and look for places where there could be possible damage to the wiring like the exhaust pipes or a wire that may have gotten pinched somehow, things like that.

One last thing that may help here is the fuel pump relay circuit. The relay for it is turned on by the PCM and grounding the relay coil. The switched power to the pump is on pin 5 of the CCRM, a dark grn/yel wire. If that relay isn’t working then the PCM should be checked and make sure all power sources to it are ok. If that checks out ok then perhaps the PCM is the problem.