My 1995 Mustang GT has an odd problem. I'll try to be brief.
When the engine is hot the car starts.
When the engine is cold the car starts.
It will always crank.
I can hear the fuel pump hum.
Here is where things get funny:
After driving a short distance (the engine is warm, but not hot), the car will refuse to start. I will turn the key to "on" and hear the fuel pump kick in.
But it will not start. If I wait a minute with the key in "on", then I will hear the fuel pump hum again, and the car will start.
I am leaning towards a bad idle air control valve or a bad fuel pump relay. I have a new relay, but I do not know where the relay is located. I have looked under the driver and passenger seats. Under the glove box has a lot of wiring harnesses, but I don't think I saw the fuel pump relay. I looked in my chilton's manual and could not find it in a wiring diagram.
Where is the fuel pump relay, and does this seem like it could be the problem?
I've got a similar problem,buit doesn't sound like it's as extreme as yours.What I think I have (and I'm not going to be upset if someone corrects me,it's just a guess) is possibly 1 or more leaking injectors.When it's cold,all the excess fuel has evaporated,so when they "squirt" A/F ratio is OK.When it's warm,I've got excess fuel in the cylinders making it too rich,so it takes a minute to straighten itself out.When it's hot,it hasn't leaked enough fuel into the intake to be too rich yet,thus starts OK---here again,just a guess
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Be aware of an item called a CCRM- Constant Control Relay Module. Mounted right by your overflow reservoir, it controls fuel pump function along with a few other things. My issue when I had cranking/starting problems ended up being in a distributor going bad, and on our SN-95 5 liters, if there is no spark signal from the distributor, there will be no fuel coming either! May not help but its some electrical to look at....
I knew there was something electrical mounted near the fluid reservoir. When I turn the key to "on" i hear the fuel pump hum and a "click" from the electrical components near the reservoir.
What was going bad in the distributor?
And where is the fuel pump relay?
I've looked under both seats and under the dash, but still haven't found it.
never went searching for an actual fuel pump realy, and if it primes for 3 seconds and you hear the ccrm click off as you describe, then it sounds to me like you dont have a crank signal from the distributor. When mine went bad, the bearings carrying the dist shaft let loose, the shaft wobbled, and the trigger wheel chewed up the magnetic pickup beneath. Could also have the issue from a bad ignition module possibly, and those are easiest checked by testing with a known good module. Even the OBD1 ford manual I have doesnt give specs to test the remote mount ignition module
Hope that helps! if it primes and kicks off, but no fuel when cranking, it sure sounds like the dist to me. Do you have any spark during crank?
Let me know what ya find out
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95 GT convertible,Powermax 2031,cobra intake,70mm t/b,76mm C&L,30# injectors, mac equal length shorties,O/R x-pipe,flowmasters,Alto red eagle in the AODE,2500 stall,transgo HD2,MSD 6AL, Tons more always in the works!
I do not know if I have spark when it cranks and doesn't start. I have a spare plug wire and a spare plug, so the next time it happens, i will test.
Would a distributor problem cause the other symptom i described:
Sometimes when it doesn't start, I can leave the key in the "on" position. After sitting for a minute, I hear the fuel pump hum again and the car will start.
Thanks for the ideas. Luckily, a distributor is easy to replace.
Well, mine was intermittent for a week or two then a final total failure... So I may be sending you the wrong direction... But I dont think it is a relay if you hear it prime? Seems like a lost signal. I have also heard of heat soak making the ingnition modules mess up, but have no certain evidence to prove it.
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95 GT convertible,Powermax 2031,cobra intake,70mm t/b,76mm C&L,30# injectors, mac equal length shorties,O/R x-pipe,flowmasters,Alto red eagle in the AODE,2500 stall,transgo HD2,MSD 6AL, Tons more always in the works!
So to fix the problem, did you replace:
1) the distributor and all of it's internal parts
2) the ignition module
3) the electronics near the coolant reservoir
I would like to narrow it down before i start pulling parts.
Thanks for the tips!
Don't be just changing parts. There are ways to test to see if something is bad. There could be more than one thing wrong. Just changing parts is not the right way to do this. I suggest checking the ignition conponents first. Make sure all grounds are in good shape as well. I have a buddy that had the same or similar problem. Both the distributor and ignition module were bad. The injectors will not open if there is no spark signal from the ignition as 95vertinFL stated. We thought it was a fuel problem as well but turned to ignition real quick. Just my $0.02
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I agree completely.
What I meant was I want to narrow it down, figure out what is wrong, and replace it. That is why I am asking for suggestions.
I was not saying that I will start randomly replacing parts, I was saying that i do not want to be doing that.
Would any of the potential problems turn up if I scanned for error codes?
Right on, dont just start swapping parts! If the distributor bearings are gone, youll see a bunch of black dust (ground up magnet from the pickup) when you take the cap off....
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95 GT convertible,Powermax 2031,cobra intake,70mm t/b,76mm C&L,30# injectors, mac equal length shorties,O/R x-pipe,flowmasters,Alto red eagle in the AODE,2500 stall,transgo HD2,MSD 6AL, Tons more always in the works!
I had the distributor cap off a few days ago. I was cleaning all of the contacts. There was a fair bit of dust and dirt. Some of it was black.
Which sensor/module in the ignition system is responsible for telling the fuel pump to pump and the fuel injectors to open?
I think that is my problem. I'm sorry if I'm not more technical. This is the first car i've owned that with Electronic Fuel Injection, so i'm not used to having all of these sensors and modules.
A bad dist will have slop in the bearings (the shaft will wobble) as far as it goes, take the cap off and the rotor, then you can take 2 screws out to take the metal wheel off below that. That is the trigger wheel. Underneath is the magentic pickup... Look at the inside of the teeth on the wheel and look at the pickup, youll be able to see if they have hit each other. Seems to be a kinda common issue! That signal goes through the ignition module, which is mounted on the passenger side wheelwell below the air intake tube. I dont have specs to test the module though. The CCRM is a whole 'nother ball game, havent had to mess with it yet...
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95 GT convertible,Powermax 2031,cobra intake,70mm t/b,76mm C&L,30# injectors, mac equal length shorties,O/R x-pipe,flowmasters,Alto red eagle in the AODE,2500 stall,transgo HD2,MSD 6AL, Tons more always in the works!
1995 Mustang GT fuel pump relay 
