After driving my mustang for a while I stop somewhere and return to my car after a few minutes, and the car just won't start, the starter turns the engine normally but nothing else is happening, then I wait for half an hour or so and the car starts without any hesitation everytime...my car has done this four times in about three months. :scratch:

The dealership tells me it's probably a problem with the fuel pump, they tell me the pressure should be 35psi but it's around 28...and it would cost $500 to change it since they have to remove the gas tank, I'm a bit skeptical, seems more like an electronic problem to me...any toughts?

 

Sometimes the solution is too easy. Try a little gas before turning the key.

Seriously, sometimes my car does not start when I turn the key, but I think it is because I forgot to put some pressure on the gas beforehand. :nono:

 

$500? :shock: that's bit hefty. Does sounds like possibly the fuel pump. Try this: have someone turn the key to 'on' (don't turn the engine over) while you are by the tank. Listen for the pump to turn on its should go for no more than say 2 seconds. If it goes longer or sounds strange (sounds like it speeding up or slowing down), the pump is probably in need of a replacement. Changing the pump is a PITA, but can be done on a Sat or Sun. Just BE CAREFUL when working with the tank, two reasons, one is that gasoline fumes are highly explosive, and two they can be deadly. There was a person locally that died in his garage while working on his Mach 1, because he was overcome by gasoline fumes with the garage door open. If you're unsure of doing it yourself, shop around to other places. I'm sure you can have it doen for less. Good luck.

 

Andre - Where are you located. I would be glad to help you out if I can. It does sound like it could be the fuel pump. The is a "leak back" valve in the fuel pump. This valve allows the the fuel system to maintain pressure even after the car has been turned off. There is an actual amount of time the fuel pressure should take to completely leak back to the tank. Also, you do need at least 35 psi of fuel pressure to get the engine to crank properly. Try this. Before trying to start the car....cycle the key to the run position (without attempting to start the car) at least 3 times (on,off,on,off,on,off,crank). This cycles the fuel pump and will build pressure even if the system will not sustain pressure, it should build enough to crank the car without incedent. My convertible did the same thing. When I replaced the pump the valve was actually missing. There are some other things I would suggest, but this post is getting pretty long. Let me know how it turns out and if you need any further help or a deal on parts or installation.

 

does that work on a FI car? :scratch:

 

Changing the fuel pump should be easy if it's anything like my 86GT was. I had a friend do it in about 20 minutes. Mine acted like that too as it got hot the pressure dropped and it would quit running. Amoco fuel would run a little cooler until the weekend I had off to change it out. Be careful!!!!

 

I read that this is a problem with some of the Sn95's.


I think it was MSN, but I'll try to find the article.....found it.

http://autos.msn.com/research/vip/Reliabil...id=1141&src=vip


Occasional problems on this vehicle are failure of the AIR Pump, the Fuel Pump and the Differential Pressure Feedback EGR (DPFE) Sensor. Failure of the Fuel Pump may prevent the vehicle from starting. The cost to repair the AIR Pump is estimated at $215.00 for parts and $45.50 for labor. The cost to repair the Fuel Pump is estimated at $230.00 for parts and $130.00 for labor. The cost to repair the DPFE Sensor is estimated at $50.00 for parts and $32.50 for labor. All prices are estimates based on $65 per flat rate hour and do not include diagnostic time or any applicable sales tax.

 

OMG. can this happen to the V-6's???

this happens to my girlfriends car. when i go see her in napa, the mustang is driven more then usual, and sometimes fails to start.
we thought it was the battery, then the alternator, then the freakin' fuse box for pete sake. :bang: :bang: :bang:
i had posted this before
past thread

we went to a couple of mechanics once we couldnt do it ourselves. they were saying the same thing we were thinking.

Thanks A Lot, now i know what to check.

 

Thank you all for your suggestions. The problem must be with the fuel pump, I should have mentioned that was $500 canadian for replacement wich is about $380 US, maybe If I shop around I can get a better price.

sscobra you are probably right concerning the leak back valve, I talked to a few people concerning this problem and sometimes the "plunger" does not work properly, could also be the fuel pump relay, it's supposed to be under the front seat somewhere but I can't find it....Thanks again.

 

Just an update, I had my fuel pump changed a few days ago, including new fuel filter, clamps and so on, $664.00 can , anyway it seems to work fine now, I even have the impression I have an extra 20 HPs under the hood, I guess going from 28 to 35 pounds of fuel pressure will have some effect .

 

This happens all the time in my moms 2003 gt we have taken it to the dealership to have it worked on under warranty, but it is still doing the same thing. i noticed today and it is funny that u posted this cause i was just about to ask the same thing. it seems like the fuel pump doesn't kick until late...are there any recalls on this?
(its good to know its not just hers that has this problem)

 

Well it just did it again, same problem as before :bang: :bang: :bang: so I guess it's wasn't the fuel pump...The dealer does not have a clue, so any suggestions would be greatly appreciated ! ! !

There is something about driving a car you know could stop at any moment and not restart, especially in traffic, that makes you think of buying a toyota.

 

yeah and by the time you get yours restarted the toyota will just finally be generating enough torwue to move from the stop light! LOL, no crack on toyotas. wish ford has the quality that they do

 

can it probably be the alternator? check if it heats up too much. my girlfriend was having the same problems. every one kept saying different things, one mechanic even said it might be because of the blinking anti-theft light
or maybe the fuse box, or.... you know what, i have no clue. after the melee of lame mechanics we had, i dont wanna think about it.
but if someone finds something, please post it!

but do check the alternator

 

Does the car die while moving or just when you shut it off, and it won't restart?

If its the latter, I'm thinking about possibly a leaky injector. If it leaks when it should be off, the pressure might be affected, but not by much, unless something is stuck in the needle valve. Also, if it leaks, it would leave excess fuel in the cylinder, but the other 5 would still work, so that's unlikely.

Let's see, cars need air, fuel, spark, and compression. Its most likely, not the air or compression, so that leaves the other two. If we eliminate the fuel, that leaves us with the coil pack that generates the spark. I wonder if something in the coil pack gets hot and will not work until the car cools somewhat. Did the dealer mention anything about that?

 

Try the ignition module. Sometimes when they get defective, they get really hot and don't want to make a connection. I know on my 95 it is the little grey thing under the air filter with the heat fins on it, but yours could be in a different place..

 

Does the car die while moving or just when you shut it off, and it won't restart?

If its the latter, I'm thinking about possibly a leaky injector. If it leaks when it should be off, the pressure might be affected, but not by much, unless something is stuck in the needle valve. Also, if it leaks, it would leave excess fuel in the cylinder, but the other 5 would still work, so that's unlikely.

Let's see, cars need air, fuel, spark, and compression. Its most likely, not the air or compression, so that leaves the other two. If we eliminate the fuel, that leaves us with the coil pack that generates the spark. I wonder if something in the coil pack gets hot and will not work until the car cools somewhat. Did the dealer mention anything about that?[/b][/quote]
Twice it died while moving, but usually the times it won't start is when it's been shut off and still warm (by the way it's a 4.6L). From the start I had my doubts about the fuel pump but the dealer assured me that was the probable cause, It seems more like an electric or electronic problem, but I don't want to change parts needlessly.

Yes could be the ignition coil or ignition module and possibly the ignition switch , logically I can't imagine anything else...Thanks! I'll have those things checked at the dealer.

How about the securlock key component could that be defective...?

 

Twice it died while moving, but usually the times it won't start is when it's been shut off and still warm (by the way it's a 4.6L). From the start I had my doubts about the fuel pump but the dealer assured me that was the probable cause, It seems more like an electric or electronic problem, but I don't want to change parts needlessly.

Yes could be the ignition coil or ignition module and possibly the ignition switch , logically I can't imagine anything else...Thanks! I'll have those things checked at the dealer.

How about the securlock key component could that be defective...? [/b][/quote]
The thing with my ignition moddule is it would not throw a code unless you were scaning the car at the exact same time it started loosing a connection.

 

It could very well be the coil pack. When is the last time you did a tune up? I would check the pcv valve also (not saying that is causing the problem, but it is good to keep a check on that). One thing It might be your IAC (idle air control module). I'm sure you and most people know that this is the mechanism that helps control the idle speed of the engine. This part operates by using a plunger valve that opens and shuts an air passage around the throttle blade. Sometimes these valves tend to stick. Carbon builds up on the plunger and causes the part not to operate properly. When your car heats up of course things expand. There are very tight tolerences inside the IAC. With the addition to carbon build up and the plunger expanding this could likely close off the air passage around the throttle blade. This means that the motor might not have the proper air flow when you try to start it even if you press the accelerator pedal (not the same thing as a carburated engine). You can try to take the IAC off and clean it using throttle body cleaner or replace it. I'm not saying that this is absolutely the problem, but it is worth checking. If is not the IAC, it is most likely a iginition coil, wire, or plug problem or obviously an injector/fuel issue. Good luck man. Let me know if you need any parts for the car. I might be able to save you some money.

 

Changed the fuel pump and filter, idle air control (IAC) and air filter but the car still stalls and refuses to restart and it's getting worse :bang:

Anyone wants to buy a used Mustang :scratch: