Need some diagnostic help...
 

My wife's '04 Mustang 3.8l wouldn't start for her today.
It ran fine as recently as Monday.
I checked the battery voltage first thing as it was suspect a few weeks ago when she said it wouldn't start for her then. It measured 12.3v.
When I went to start it this afternoon, it cranked just fine. It wouldn't crank for her at all this morning when she wanted to go to the store.
I pulled a plug and had her crank it while I checked for spark. It has a nice spark, nice and blue.
Will an OBD reader tell me if the fuel pump is having a problem?
I checked the fuel pump switch in the trunk and it was/is fine, ie not tripped.
I'm stumped as I'm old school (or should that be electronically challenged?), Chrysler Trouble Shooting Contest trained from high school. This new EFI stuff is great when it works but...
Any ideas from the trusted brain trust here would be appreciated.
Thanks.

Sounds like you used a good systematic process and narrowed it down to the pump or the fuel electronic system.

The spark plugs are firing, so the crank/cam sensor is good.(btw there is a clip-on-fake-plug tool which makes removing a plug not necessary.)

A "noid light" will show a quick check if the injectors are firing(or being told to).
There should be a shraeder valve on the fuel rail to check pressure.

There could be a bad ground connector on the electronic side.
Checking voltage at the pump might be the last step.
I'd think a weak pump would be problematic with loss of power for a while first, but it could just croak.

btw, saw a guy holding onto the plug technique.
Looked down, and there was a spark jumping to the bumper from his jeans!

There is a fuel pump driver module in the trunk, on the drivers side. Looks like a small brick, half black and half silver colored. You have to check for power coming out of the module to the fuel pump.

http://forums.pelicanparts.com/uploa...1348717621.jpg

These modules are prone to failure. In the occasions I've seen these fail it was after the car had been sitting for a while. It may be pure coincidence, I have no idea. I do know that a lot of the issue is the lack of relay for the module and it's not uncommon to find an aftermarket relay added in to cure the failures.

wow, I have the bosch part number still on my notepad. "67170'

Thanks Scott!
That is the kind of help I was looking for.
I'll check it out when I get home this afternoon.
Is the module located near the switch by chance? I found it right behind the left tail light assembly, right where the owners manual said it would be.
By the way, the car has been sitting a while, other than being driven on Monday. It was probably sitting for a week or so before that and it's been super hot in our garage with the weather we've been having lately, if that makes any difference.
I'll report back with any findings.
Thanks again for the help.

The fuel system and ignition system has nothing to with it cranking over.

If it doesn't crank, it's the starter (bad spot, solenoid), wiring (corroded, fatigued, loose/intermittent connection), or switch (physical contacts, wiring, anti-theft). It could also be an interlock that doesn't allow the starter to engage, like the gear position switch.

If you stated it incorrectly and the engine/starter is turning over (cranking) but not firing, then look at the fuel system, including Ford's fuel pump cut-off switch located on the driver's LH kickpanel.

Since you have a spark I will assume it is turning over but not starting.

I would spray some quick-start into the intake and make sure it fires, if it does you likely have a fuel problem. But it certainly sounds like you don't have fuel.

Get a cheap noid lights to check if your injectors are firing.

But to answer your question, it is unlikely OBD II will diagnose your 'no start'. The 'check engine' light turns on with the ignition (this indicates the ECU is running), and then it should turn off after a few seconds. I don;t think you can tell if you have stored fault until the car starts and runs.

This could be hard to diagnose, from you description it is intermittent?

Yea, this was the confusing statement for me as well, but I figured unless he was triggering a spark event without cranking it had to be a typo?

I've had an experience with Bosche + Fuel.
An 87 Golf wouldn't start again after running a bit.
Intermittent.
I thought it was vapor lock or a head temp sensor or something along those lines.
It was overheating due to another problem(radiator core rusted shut and popped), and there was lack of cooling fan due to some source(thinking ecu after throwing sensors and thermostats at it).
Then it quit while driving. Hmmm, something's hot on the fusebox.

Turned out to be the fuel pump relay.

First, thanks for the help guys.
There is a bit of confusion now on my wife's part as to whether or not it was cranking when she went to start it the yesterday. That is why I checked the battery voltage first.
Since it is cranking (yesterday, I haven't tried it today yet) and it does have a nice blue spark (at least on the plug I pulled) I think it's the fuel system. I've never heard this fuel pump, unlike our Taurus which was noisy as all get out, and I don't hear it now. I'm going to look for the module in the trunk and see if it's getting power.
I have some starting fluid I use on my lawn mower and will try some of that if I can't find the module.
What is a 'noid light'?
I've never heard of one before.

Noid light: Unplug the injector(s) and attach a light.
It flashes when the injector is pulsed by the computer to open(squirt fuel).

It means the electronics from the crank/cam sensor to computer to driver to injector is working.
(but remember signal not voltage/timing/dwell/etc....It only indicates some sort of signal is being sent).

Here's one place, but a specific search gave crap results though. I don't have time to go through them all. A universal kit will probably work.
noid lights - BuyCheapr.com

OK, making some progress here.
FOUND the module on the pass side inner fender in the trunk.
Took it out, unplugged it, hooked my VOM red lead up to #9 term of the connector in the car and touched the black lead to ground with the key in the 'on' position and got a reading or 11+/- volts. I think the module is indeed kaput.

What is the output of pin #3 when the car is cranking? I don't think 11v at pin #9 is an issue, the battery may just be a little low. Pin #3 is actual power supply for the pump and the module is not working it tends to not drive pin #3.

You should get a priming pulse to #3 when you first turn the key on, then it should be hot while cranking and running.

We still don't know what your definition of cranking is.


Cranking is something you would do with a crank at the front of a model T regardless of whether or not it starts.

OK, thanks for that. At $163 quoted price I need to make doubly sure it's the module.
I'll go run that test now.

Cranking = turn the key and the engine turns over (ie starter is working fine) but it doesn't fire. It's the kind of thing that wears batteries down in a hurry if you're not careful.

I THINK I may be doing this wrong...
I put the red lead of the VOM into pin 3 on the connector in the car and had my wife crank the engine over, got nothing. Should I be hooking the module up and piercing the wire from pin three instead?

11V? Put a charger on it asap.
That's starting to sound like dead mode.

The electronics might not function if they get <9V while in crank/start mode.

Re-ran the test with the module plugged in.
Red lead piercing the wire from #3 and black lead on ground, engine cranking, got a reading of .7v. Point 7 volts is not going to run the fuel pump I don't think.

john70t - it may look low voltage wise but it's cranking over same as it always has, with lots of vigor. It could have been my um, less than perfect connections that gave the 11v reading.
I really think the module is shot.
Now to find one...

That's what they read when they die. The last thing I check for my own sanity is to borrow 12V from a nearby source and jump pin #2 and listen for the pump.

Scott, I really appreciate your help here.
Do you mean apply 12v to pin 2, with the module plugged into the car, I should hear the pump run then?

With the module unplugged I jump 12v into pin #3 the (+12v to pump pin) and listen for the pump.

Got it. Thanks.

Got a new module on the way home from work.
Plugged it in, bolted it down. Turned the key and got the same cranking but no start.
I'll try jumping the pin as I still don't hear anything like a pump in the trunk.
I wonder if the pump went south and fried the module???

I jumped pin 9, which showed 11v with the key on, to pin 3, as you suggested Scott, and it didn't do anything back in the trunk, like emit the sound of a fuel pump running. This was with the key in the 'on' position. It does have a full tank of gas in it (of course) if that is a help. Fuel pump bad?

Check fuel pressure at the rail, just push the schrader valve in if you don't have a gauge. Lets see if the pump is charging the fuel rail.

http://carphotos.cardomain.com/ride_...4008_large.jpg

Yup. That there is a Schrader valve, but, for the life of me I can't find one on my fuel rail...

http://forums.pelicanparts.com/uploa...1348879001.jpg
http://forums.pelicanparts.com/uploa...1348879010.jpg
http://forums.pelicanparts.com/uploa...1348879021.jpg
I appreciate the help.
I also have to cut the grass right now but I will check back later.
Can't believe I can't find the valve...:confused:

Update: this is a 3.9l engine it turns out. My mistake I thought it was a 3.8l.

It's either TBI (central throttle body feeding all cylinders which replaces a carburator), or individual intake runners (port injection-there are several kinds).

Back to square one. Is the check engine light on?

Did you ever squirt ether in while you were cranking the engine?

Thanks for hangin' in there with me on this guys. Got more than frustrated with this yesterday and had to walk away from it.
First, here's a picture of the instrument panel when I turn the key to the 'on' position.
http://forums.pelicanparts.com/uploa...1349018780.jpg
Sorry for the out of focus, I hurried it.
No check engine light. It does say 'Service Engine Soon' though.
I haven't sprayed starting fluid into it yet, but will later this morning when the neighborhood wakes up. I hate making a racket before 10 on Sundays especially.
I did buy a manual, if you can call it that, I wouldn't if I were the publisher as it doesn't even make mention of the 3.9L engine. I think it's a Haynes.
I did attempt to siphon the gas out of the tank. That was a fiasco too as the tubing is so flimsy it won't go down the tank filler turns to reach the gas.
I did give the tank a few whacks with my new rubber BFH that I recently bought at H-F, just to see if I could jar the pump some. No dice. That's when I walked away from it.
I did check the fuse under the hood for the fuel pump circuit. All is good there. Why do they make the owner's manual pics so small you need a magnifying glass to read them?
I will give the starting fluid a try later.
If that doesn't work I'm ready to say 'uncle' and have it towed to a local indy I know to let him deal with changing out the fuel pump (which I'm betting is the cause, based on my Taurus experience).
Hate to say it, but I'm a Chevy guy that only has a Mustang in his garage because that's what his wife wanted after her mini-van driving days were done. As she says, we haven't spent a dime on it since we bought it used 5 yrs ago except for oil and gas. It only has 52k miles on it now so I guess the bean counters did their job right as it seems Detroit iron only lasts 50k miles now and it starts to fall apart, at least that's been my experience with the last 3 of 4 American cars I've owned.
I'll check back later with the results of the starting fluid test.
Thanks.

Based on your comments, you're in way over your head

It's not a big deal to replace the fuel pump in a 2004 Mustang, and I'd guess that's your issue. You should be able to DIY if you have the fuel line clamp tools and a way to drain and lower the fuel tank. Guys that are good at it can do it in 45 minutes. It will take a DIY most of the day. It might take you all weekend.

Airtex #E2366 ~$85, will have to swap some parts over from your bad pump
Delphi #FE0443 ~$95

Don't forget to buy a new gasket for the fuel filler neck ~$20

Fuel pumps can last two years or two decades depending on care. No use blaming Ford for a nine year old car's pump going bad.

No offense taken Eric (I really enjoy your posts by the way) but I'm not in over my head here.
I considered myself just above water when I did this:
http://forums.pelicanparts.com/uploa...1349025183.jpg
to fix my Sportomatic diaphragm.
Right now I'm more frustrated than anything with the 'built for assembly line ease' design of fasteners, clips etc as I don't have a ready source for all that kind of stuff.
Dealing with a full tank of gas, at home in my garage isn't that hard, I admit. But in my present state of mind (I've been told my last day at work is the 19th of Oct, after 17 yrs) is not the best for dealing with this and it's something I hadn't thought I'd need to deal with since the car has been good up until now even under my admittedly neglectful care. Our Taurus pump taught me you don't let the tank go below 1/4 full for long as the gas cools the pump. I've treated the Mustang by this rule and here we are, 52k miles in and it needs another one.
Anyway, I put some starting fluid in it and it wants to fire off, so I'm pretty certain the ignition system is OK.
If I had a lift and didn't have to crawl around on hard concrete, this job might appeal to me more to save the money. But right now with the weather promised to be some of the hottest of the summer, I think I'll let the money go and take it to my friend's shop. I'll just consider it redistribution of some of the white collar welfare I've been receiving for the last 12 yrs from my former project.:p

Sorry for coming off harsh, but when you referenced the 'Service Engine Soon' light differently than a 'Check Engine Light' and taking a photo of that light illuminated when the key is in the 'on' position but not running led me to believe these newfangled cars may be beyond your current knowledge.

BTW, every car's CEL/SES light is illuminated when the key is in the 'on' position. All the time. It will go off a couple seconds after the car is running. Not running = light is on. So you can only see an indicated problem with the car running. The only way to see if the car's CEL/SES light would stay illuminated or not in a car that doesn't run is to retreive any stored codes with a scan tool. If your fule pump has failed it may show a stored code, or may not.

Checking the fuel pressure at the fuel rail is the way to know for sure. If you don't have access to the gauge or knowledge then you're simply guessing.....educated guesses aren't a bad thing. If you've gone down the checklist and you're left with the fuel pump as the most likely culprit, then replace the pump. Scott has given you great advice with the pump driver, but you can also simply listen for the fuel pump buzzing in the tank for a couple seconds after turning the key to the on position (not attempted start). If you don't hear buzzing, then either the fuel rails are completely pressurized (unlikely) or the fuel pump isn't working.

Did you check the fuel pump inertia cutoff switch I referenced a few posts back? It's like a circuit breaker for the fuel pump if the car is in an accident. Simply press the reset button and it restores power to the pump.

You're right, these newfangled cars with all their idiot lights are beyond my training, such as it is/was. Taking out a gas tank isn't, under normal circumstances. Life has been anything but 'normal' for the last 45 days.
If I crank the car long enough, all the dash lights go out, but that is only when I crank it for what I consider to be a really long time (+10 secs). I don't like running a starter motor that long. If it hasn't started by then, it probably isn't going to. I don't have a scan tool nor a pressure gauge suitable for checking fuel line pressures.
I did and have checked the inertia switch numerous times, it's good as I've never found it tripped during all this episode.
I appreciate the help offered here as I hate having anyone work on my cars if I don't have too. They never seem to treat them the way I do, or I try to.
Thanks for the part numbers/pricing too. It gives me an idea of what to expect.