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1993 Mustang cobra need help with starting problems

3531 Views 19 Replies 8 Participants Last post by  clmun93
Hi all, my name is Jim. I have a 93 Mustang Cobra, I bought it new, so there are no issues from a previous owner. Over the past couple years I've hardly driven it. Recently the last time I started it was about 2 months ago. So, the other day I go start it and it won't start, the fuel pump won't stop priming. The first thing I did was replace the fuel filter (hadn't been chganged since 2003, only had 12,000 miles on it though). The pump still won't stop priming. Now I have read here that the relay may be stuck closed, and that I should rap it a few times to see if it unsticks. I have one question, where is it located, I can't seem to find a definitive answer, in some threads I read that it's under the passenger seat, I've also read it's in the fender well, also read it's under the hood in a box, it's very frustrating.
My other problem aside from the fuel pump issue is it won't start. I have fuel in the lines, I know cause I relieved the pressure in the line from the schrader valve, don't know how much pressure it had. I haven't had a chance to check for spark yet. I've also been reading that this could be caused by the PIP going bad, I can't find a procedure for properly checking it and replacing it if needed, can someone point me in the right direction. I've been doing so many searches and everytime I get over a hundered pages of results and none seem to fit my propblem, I keep trying to refine my searches but I keep getting the same results. I don't have time to go through so many results. I really think I can find help here, stang owners come to the rescue. Thanks for the help.
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Thanks for that piece of info. But where is the fuel pump relay?
We'll find you more info in this section.
Thanks for the assist. Been crazy trying to nail down what's happening, it's especially frustrating when everyone is saying the same thing but none of it looks the same, meaning, like where is the freaking fuel pump relay for the 93 cobra? that's not all of the problems but I'll tackle one at a time. By the way, what is the ecm, pcm, eec, ccrm, I thinnk some of these abbrev. are for the same thing. Like I said it's a little frustrating. Thanks again.
I've been reading many threads and posts from various forums and just googling stuff. I've found a lot of information and pics and videos. I've also found more terminology that confounds, I've read the word dizzy and I figured it means the distributor, I've also read spout. I've read where someone was having starting issues, and decided to diconnect the spout and the car started right up without any problems, then he reconnected the spout and the car wouldn't start again, what the hell is the spout?
check the ecm for leaking capacitors...i have the same problem, with the same car. :rollgrin:

my problem is the ecm.
Mightyjoe, have you checked yet into what a new ecm is going to cost. Are you going to get it from the dealer (if they still carry them) if they no longer carry them, where else can it be gotten? or will it have to be repaired?
By the way I sprayed starter fluid into the intake and the car started and ran until the fluid was used up, so the fuel delivery system is no.1 suspect, but I will check ecm as well. I'm also thinking I have fuel pump issue. The pump has been making noise for years (humming sound) whenever I filled tank all the way I would hear the humming, usually the radio drowned out the noise. When the tank would get about half full or a little lower the humming would stop. My idea was to just run it until it failed, only it's been years now, and it may have finally failed, not sure though. The pump energizes when I turn the key on, it sounds like it is trying to prime the line, and never stops priming. So I still need to check more stuff. I have the rear jacked up and may just go ahead and change the pump while it's up in the air. Oh I also diconnected the vac. hose from reg. to see if any fuel was coming out of it, nothing came out, so I'm hoping that's a good sign. Last week I had checked the fuel line to see if it had fuel and pressure afte I changed fuel filter, I checked after cranking engine. The line had pressure and fuel, I have no gauge to check pressure so I have no idea how much pressure there was. I'm going to get a gauge to install on line.
If your pump is coming on and not cutting off when primed, your problem could be the filter or the pump. The regulator is what turns the pump off once enough pressure is built up in fuel rail. Try to borrow a gauge and check the rail pressure. I'm thinking it should be around 30lbs. You need to make sure you have enough fuel pressure before swaping out more parts.
The relay is on pass fender wall in engine compartment under MAF just replace it. Then check your fuel pressure at the schrader valve (on fuel rail behind alternator) Should be around 40# if not then the pump is bad. Also you could pull apart the ecm and look for a bad spot.
Bass and Spd and Mightyjoe, thought you ight want to hear this. Stopped by my local Ford dealer and thought I'd price a few things. First I asked about a fuel pump, price=$404, retail, the guy was gonna give me a break ($365), i had to laugh, then I asked about a fuel pump relay and eec relay. The pump relay was $60+ the eec relay was I think $50+ it was hard not to keep laughing. I also asked him to show me where the fuel pump relay is in the car, according to the diagram he has in his computer it's in the diver's side kick panel, but he said it could also be on the fender well under the maf, or the firewall, or even in the pass. side kick panel. Oh and all the parts have to be ordered. I told him what's going on, he said I should talk to one of the techs, so I did.
The tech was saying a lot of what everyone on here is saying, but when I mentioned that the pump keeps going and doesn't stop after turning keep to on and that there is pressure in the fuel line, right away he said the pcm, just like you said mightyJ, he said take a look at it. The thing is that ford no longer carries the damn pcm so now the hunt begins. Anyone had to aquire a pcm for a 93 must. cobra recently? if so please tell where, and cost. thanks.
1993 FORD MUSTANG COBRA ECU X3Z COMPUTER 93 5.0 83-93 : eBay Motors (item 270596711168 end time Jul-01-10 00:05:25 PDT)
There's that, a fuel pump can easily sourced for about $100 on Ebay as well...a good Walbro 255lph is a common item...good luck, have fun!
Hmm, mine is an 89 and my fuel pump relay is under the drivers seat. Did they move it later?

Also, I believe the Motorsport ECU calibrated for 24lb. injectors is the same as your ECU. That may broaden your search past just a 93 Cobra.

.....I was just thinking too, it seems that the X3Z was not as favorable in timing curve, etc. as an A9L. Maybe someone with a bit more experience can back me up, but I seem to remember 93 Cobra guys switching to an A9L and getting a 24lb. MAF unit.
Thanks for the effort, but the guy on ebay with the computer is selling used, not even reman. starting bid is 299.99 and no returns accepted, I can just see my money sprouting wings now, never to be seen again, LOL.
But I have found some companies offering ecm/ecu/pcm with lifetime warranty, so those of you needing a computer for your 93 cobra here's what I have found so far GoECM.Com - Reliable Auto and Cummins ECM/ECU Dealer $295.00 $50.00 core charge with lifetime warranty, also found ECM TECH INFO - FAQ - HOW TO KNOW YOU NEED AN ECM, they tell you how to troubleshoot and make sure it is the puter, and they sell them. I couldn't find any order numbers or prices for this site, check them out. I'm gonna keep looking.
Yes white89, apparently they did move them, don't know exactly when, but I feel like I'm gonna have to look all over my car to find the damn thing.
Hey white89gt, I'm trying to keep my cobra as stock as possible, I'm the original owner and since it is 17 yrs old and still in my possesion it is in my favor not to stray much from stock. The car has always run good, it has never given me any problems other than normal wear and tear, water pump, radiator, alt. things of that nature. This is the first big problem I've had, and soon I expect to resolve it.
I need to find a reliable and reasonably priced supplier for a ecm/pcm/ecu in the event i need one. The cobra has 110,000+ miles on it, I have enjoyed it and once I clear this problem and get it roadworthy again I expect to ennjoy it many more miles.
update to my no start problem

Hi all to anyone following my no start problem, I'm bringing everyone up to speed as to where I am. I just installed a fuel pressure gauge on the rail, when I turn the key to engage the pump it goes immediately to 40 lbs. so the pump is pumping, it still doesn't turn off after priming, but it's better than not working at all.
As I mentioned previously the car does start when I spray starter fluid down intake, but turns off once that is used up, therefore the ignition system is sound, the pressure regulator and pump are sound, the only things left are the control module on the dist. and the eec and the ecm to check and maybe the injector pulse, the 2 things i highly suspect are the module and the ecm, I'll leave the ecm for last since it's the most expensive and right now the hardest part for me to get to because of the way the car is parked.
The other stuff I have access to check so I'll finish checking them first. In the event I do need a puter does anyone have any suggestions where to get one? I don't want any used straight from the car unit, since it probably has the same leaky capicitors just like mine might have. let me know.
update to my no start problem

Hi all to anyone following my no start problem, I'm bringing everyone up to speed as to where I am. I just installed a fuel pressure gauge on the rail, when I turn the key to engage the pump it goes immediately to 40 lbs. so the pump is pumping, it still doesn't turn off after priming, but it's better than not working at all.
As I mentioned previously the car does start when I spray starter fluid down intake, but turns off once that is used up, therefore the ignition system is sound, the pressure regulator and pump are sound, the only things left are the control module on the dist. and the eec and the ecm to check and maybe the injector pulse, the 2 things I highly suspect are the module and the ecm, I"ll leave the ecm for last since it's the most expensive and right now the hardest part for me to get to becuase of the way the car is parked.
The other stuff I have access to check so I'll finish checking them first. In the event I do need a puter does anyone have any suggestions where to get one? I don't want any used straight from the car unit, since it probably has the same leaky capicitors just like mine might have. let me know.
how did you figure it out?

check the ecm for leaking capacitors...i have the same problem, with the same car. :rollgrin:

my problem is the ecm.
Mightyjoe how did you determine for sure it was the ecm? and have you found a place to get another one? duh, what a dummy I am, you said leaky capacitors, I can't erase this so I added in the duh. anyone i still do want to know if you have found a place to get the ecm yet. let me know.
computer

hi, i have a 1993 cobra and in the past i haved the same problem ,i change the ecm computer and the problem fix, i look the original ecm incide and find the capacitor leaking thats is the real problem ,try and lets me know thanks.
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