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2000 Ford Mustang- Please advise!

Hey everyone, I hope you can help:
I have a 2000 ford mustang V6, and it is the standard model; not a GT. about 6 months back, I got in it after work and the engine turned, but the mustang would not start. The guys in the auto garage next door jumped it with their jumper, and it worked fine all the way home, just like it always drove. But when I went to start it up again, it would not start. The diagnosis was a bad battery. (I already knew I needed a new one). Well, I have a Nissan that I drove in the mean time and never went to replace the mustang battery.

6 months later:
I wanted to sell the car and I told the guys that it just had a bad battery. However, we could not jump the car. I’ve had 3 people tell me it is the fuel pump, but I am having a really difficult time believing that the problem is the fuel pump when I know it was the battery before. I hadn’t been driving it, and it’s tough to believe that it would just break. I was able to start the car with starter fluid being shot directly into the engine, but it shuts off shortly afterwards. I also checked the inertia switch or whatever in the back left of the trunk to see if somehow that was set off. One guy I talked to that knows some things about cars told me to check this valve when the key is just turned to “on”. He says that if I press in and it sprays fuel, that it isn’t the fuel pump, and it could be a relay for the fuel pump or something. Anyways…Maybe I am just in denial because I know it requires dropping the gas tank etc, and that will cost me 600+ dollars. And I for sure do not want to do that if I am not even sure if it is the fuel pump.
*I just want to get some insight; maybe someone has experienced this? Maybe it is common with this Mustang model and possibly a quick fix? I hope so. Please, Please, please advise. (The gas tank is 1/2 full).

Am I correct in assuming you tried to sell the car, knowing it had a bad battery?

Anyways . . . from what you described, it certainly sounds like you might have a fuel pressure problem

I believe your engine might have a fuel pressure test port. If so, please hook up a gauge and report back to us

For the record, just because you earlier had a bad battery, doesn’t mean you can’t now ALSO have a bad fuel pump. Sometimes, things just quit without any kind of warning

Are you quite sure you have enough fuel in the tank to start the engine?

About that inertial shut off switch, was it tripped, did you have to reset it? . . . you said you checked it, but you never said what the result was

I would also check if the fuel pump is getting power and ground. Without getting into too many details, you can do all that from the inertial shut off switch with a multimeter

Since it does run briefly with starting fluid, we can assume your secondary ignition system is in reasonable shape, so if it were my car, I’d install a fresh battery . . . or at the very least a known good battery . . . and then concentrate on the fuel delivery system

Thanks for the speedy response!

The answer is yes- I knew the battery was bad, but I clearly communicated that the car had a bad battery to the potential buyers; they brought the jumpers. Yes, I have a 1/2 tank of gas and it is full of fresh oil. I know that it can have two problems at once, but I hadn’t even been driving the car so I didn’t think it would be an additional problem. The switch was not triggered, but I did a reset anyway, as per the manual’s instructions- no difference after the reset. I checked the amp for the fuel pump, but I am wondering if one of the four relays is tied in with the fuel pump? It turns over just fine- It always seems like it just about to start but it doesn’t. I was pointed to a valve, almost like the valve to fill up a tire to press in and test for spraying of fuel. It looks like this:

Is this the same test you are talking about?

When I get back home tomorrow, I will try any test you suggest or even check any relay that is tied to the fuel pump. Let me know.

If your fuel pumps up pressure gas should spray out of that valve if you depress it . You won’t know how much pressure you have though unless you hook up a gauge . If nothing comes out you’ll know it isn’t pumping fuel at all . Just turning on the key should cause the fuel pump to run & give you some pressure , if your battery has power & that valve is in the fuel rail ?

I have just been parking my Nissan next to the mustang and powering it that way. So, it has power. I am not sure about the fuel rail thing…The guy who mentioned it said the valve was on the “fuel line.” I haven’t double-checked anything yet…I just wrote some notes down about how to test it. I’ll be flying back into town tomorrow. I will check over some things then. If anyone else reading this thinks there could be something else causing this problem, aside from the fuel pump, please let me know.

You didn’t drive the Mustang for 8 months and you have another car. Do you have any idea how old the gas in this car really is? That alone could be the problem.

This makes no sense. If the engine was turning over but not starting I fail to see how the battery could be at fault.

OK, Maybe the car did have a bad battery.

That’s pretty definitive that it’s a fuel supply problem. Probably a fuel pump, but hard to tell over the web.

The car has been sitting for 6 months. If it didn’t need a battery before it probably needs one now. And I wouldn’t really question a 17 year old fuel pump that quit after sitting idle for 6 months.

Isn’t that how most things break? My roof was fine one day, leaked the next. The starter on my wife’s car worked fine one morning but not that afternoon.[quote=“james_jjd_2009, post:1, topic:97965”]
I know it requires dropping the gas tank etc, and that will cost me 600+ dollars. And I for sure do not want to do that if I am not even sure if it is the fuel pump.

Don’t worry. No shop–no reputable, professional, trustworthy shop–would do that work without properly diagnosing the problem first. You don’t just walk into the dentist and say “root canal, molar 3 please.” He does an exam before fixing anything.

I can’t magnify that picture

But I can tell you this

If your engine has a fuel pressure test port . . . some manufacturers do not provide one . . . it will be on the fuel rail, which is typically metal

FWIW . . . that pictures appears to show a fuel pressure test port

If you get your hands on a fuel pressure gauge set, be forewarned that Ford often uses a smaller test port, versus most other manufacturers. So you’ll need to make sure you’re using the proper adapter

“I checked the amp for the fuel pump . . .”

Please clarify

Did you check the amperage drawn by the fuel pump, using a multimeter?

Or did you check the fuse for the fuel pump?

“It always seems like it just about the start but it doesn"t” . . . that statement, along with the fact it briefly runs with starter fluid, pretty much confirms you’ve got a fuel delivery problem. possibly the fuel pump is not doing anything at all. Possibly, the fuel pump is energizing, but the pressure at the rail is simply too low to allow normal starting.

Or maybe the alcohol in the gasoline has eaten the fuel pressure regulator diaphragm and the car no longer builds enough pressure to start. The “spray out the test port” test won’t tell you that nor will a fuel pump amp check. Hook up a pressure gauge as several have suggested. Low pressure = no start. Work from there.

This is why buying a non-running car is a BIG risk, even for knowledgeable buyers. “Ran when parked” means run Forest, RUN!

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On most vehicles you can hear the fuel pump running [ if it is running ] when you turn on the key . I had a truck that ran fine when parked & the fuel pump went bad while sitting . It sat quite a bit longer than yours did though .

Alright everyone, thanks for your input. I flew got back in town today and did the pressure test. Plenty of pressure; it sprayed a high pressure mist of fuel when I depressed the stem in the valve. So…

Earlier I said “amp”…I apologize I meant fuse. For the guy who asked if I tested the fuse to the fuel pump, the answer is sort of. I pulled out the 20Amp fuse. I noticed it was NOT blown, however I replaced it anyways to be safe. Right now, since we are getting pressure, I am going to check the manual and see if one of the relays is associated with the fuel pump, as that is the only other thing I have not checked yet. My other suspician- although others disagree- is cleaning out what I think is called the “crank case.” It has been said that the car can behave the way I explained if enough carbon deposits build up inside of the crank case…Let me know if anyone thinks of anything else. Very relieved that this may not be the actual fuel pump itself which means I would not need to drop the gas tank. (way to big a job for me). Let me know if you think of anything else.

Sorry, but what you described isn’t a real fuel pressure test

That was more of a guess. And you might be dead wrong, in assuming your fuel pressure is fine

Until you hook up a gauge to the fuel pressure test port, and report back with the readings, I don’t have any more advice

A fuel pressure test kit doesn’t have to be expensive.

I am of the opinion that carbon deposits are NOT the reason your engine is not starting

Everything you’ve said points to a fuel problem

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A lot of car parts stores will rent you a fuel pump pressure gauge. Most of the time it doesn’t cost you anything, you put down a substantial deposit but you get it back when you return the tester.

Okay…If you see here:

I circled the 5 relays in red pen, and the fuse associated with the fuel pump is circled in blue pen. The manual does not specifically say that any of these 5 relays are associated with the fuel pump. You can see the relationships in this next photo in my next comment.

While I wait responses about the relays, I am going to go double check the fuses 3, 4, and 5 since they have to do with starting.

You can backprobe at the inertia shutoff switch, and determine if the pump is being energized, without dropping the tank or messing with those relays

Wouldn’t gas spraying out of the valve determine that the pump is running ?

Yes, that is what I am told. And, it is in fact spraying with high pressure, so I am exploring the Max fuses, which seem to be just fine.

I am a little perplexed right now. The fuel pump is working, but no fuel is getting to the engine. (According to outside observers). Then it must be something that is affecting the fuel pump- Fuse, inertia switch, etc. I checked the 20 amp fuse for the fuel pump, and also check the 3 40amp max fuses that are associated with ignition switches etc. and they look fine. Perhaps I should try resetting the inertia switch again? Anyone have any other suggestions? Running out of ideas.

Just because there’s “gas spraying out of the valve” does NOT mean there is sufficient pressure for the engine to start

My advice remains the same . . . hook up a gauge and report back

BTW . . . I don’t understand what you’re up to. I’m trying to help OP, and you’re defending his denial of a fuel pressure problem, but he hasn’t even tested it properly

Ebay even has fuel pressure testers for less than $25 and free s/h, so money shouldn’t even be a factor

Alright alright. I’ll test the pressure. What is sufficient pressure for the engine to start and remain running? If it turns out to be a pressure issue, How to I increase the pressure?

Hook up a fuel pressure gauge

This one’s about half the price of the first one