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Discussion Starter #1
I drive my car every day and I've never had problems with it cranking or running...until about a week ago. One morning I went to crank it up and it died just as soon as it started...and at the same time the check engine light came on (it has never came on before). I tried over and over to drive it, and it will idle sitting still but dies when I try to drive off. So I can crank it up...and it will just sit and idle as long as it's sitting still. I can get it to drive sometimes for about a block then it will throw a check engine light and just die.

The weird thing is... I figured out that the car will kind of run without the spout connector in place. When I removed the spout connector the car cranks, but backfires and sputters while I'm trying to drive down the road. AND to make things even more weird... After driving the car while backfiring and sounding like it's running on 4 cylinders for about 15 mins. while the check engine light constantly coming on and going off... the car will all the sudden start to drive like it's supposed to...??? How this happens is beyond my understanding. It has done this over and over as I have had to drive it the past week. I'm afraid that I will destroy my engine or permanently break something if I continue to drive it like this.

I took it into a shop yesterday and had a diagnostic ran to see why the check engine light came on.

Here is the list of codes it had stored in the memory:
-18
-66
-87
-91
-96

I have no idea what these codes mean because the guys couldn't help me and rushed me out of the shop.

What do the codes mean...and does anyone have a clue what might be wrong with my mustang??

I'm really frustrated at this point and really don't know where else to turn!

Any help would me MUCH appreciated!!!
 

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Sounds like a fuel pump . I would check the fuel pressure .
 

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Replace the fuel filter while your under there too ;)
 

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Discussion Starter #4
I already replaced the fuel filter a few weeks ago. What kind of fuel pump should I get when I replace it?
 

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stock pump is 88LPH, I would go for at least a 190. Any fuel not used by motor is returned to tank.
 

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Discussion Starter #6
I found my Haynes manual and the codes mean:
-18:Spout circuit open. <---I know why this one is here.
-66:No mass air flow sensor signal. <--- Is this bad?
-87:Fuel pump circuit.<----What does this mean?
-91:Oxygen sensor problem, fuel pressure out of spec. range.
-96:Fuel pump circuit.<---Once again??.. Why is there two of them?

So I know why it's kicking code 18 (because I pulled the spout to be able to drive it) and code 91 is due to the fuel pump circuit problem...I think--> (whatever a fuel pump circuit is??)

It says in the Haynes manual that a home mechanic can't fix a fuel circuit problem, and I need to take it to a certified mechanic to fix it. Once again.. what exactly is a fuel pump circuit???

Will the car run with a bad mass air flow sensor? And what exactly is the function of the MAF sensor? And finally...is it important/needed?
 

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Discussion Starter #8
All of my ground wires? I wasn't aware of more than one ground. The main ground coming from the battery terminal is the only one I checked...and yes it's good! As a matter of fact I replaced the positive and negative wires going to the battery when I bought the car because they were both hanging on by a thread.

Where exactly are all the ground wires located?
 

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their is one on the back of the block aswell.. it should be atatched to a stud its located on the lower intake it should be the last bolt on the lower intake on the pass side near the fire wall
 

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Discussion Starter #10
Ok... so today I put a new ignition control module on the distributor(had the old one tested and it was BAD). I replaced the mass air flow sensor with a new one. After that I bought a MSD distributor cap and rotor and replaced them as I checked all the spark plug connections (wires and plugs are a few weeks old). Then I found a melted fuel pump relay laying on the passenger side header, just underneath the mass air flow. I thought this was the problem...but I also replaced the burnt relay with a new one...and after all that...

THE CAR STILL RUNS THE SAME!

It didn't make any kind of difference at all... :headscratch:

What should I do now?.. I'm leaning toward a fuel pump issue, but don't want to just replace it for nothing if it's a wiring issue or something like that... How do you test you're fuel pump?
 

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when you cycle the key do yo hear it turn on? if not check
the relay for the fuel pump is located under the driver seat.. check the inert switch in the trunk by the driver side tail light
turn the key on and check if their is fuel pressor at the check valve on the fuel rail its located on the feed line near the water pump
 

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Discussion Starter #13
Well I checked the wiring for the fuel pump and it's not melted or mangled in any way... bought a new fuel pump relay... unplugged and re-connected every sensor I could find on the engine (everything seems to be functioning correctly).

After that it still idles sitting still like it's supposed to, but when I attempt to drive it. It sputters then stalls and the check engine light comes on... OVER and over again.. And I keep cranking it back up...and if I punch it to the floor... it will light the tires up and run like a scalded dog...but when I slow down to turn or stop for a stop sign... it DIES

UNTIL...it gets to normal driving temp. THEN...it will drive like it is supposed to...???

So..if I mess with the spout connector...and attempt to keep cranking it back up and trying to drive it... Eventually at mid range temp. it starts driving like it did before it started all this nonsense.

I'm getting a diagnostic ran on it again tomorrow or the next day...and maybe I'll have a list of new check engine codes to work with....??

Has ANYONE ever had this problem with their stang before????

And do you guys still think it's the fuel pump? It cycles like it's supposed to when I turn the ignition on...and the car doesn't get starved for fuel when I'm sitting still revving the engine and sometimes even holding the rpm at 3000-4000 for a couple minutes when trying to get it to temp so I can drive it... it just dies when the car is rolling..... like movement is tripping something?

It doesn't make any sense to me...and I don't want to keep wasting money on parts I don't need... Besides checking the fuel pressure. What else could it be?

anyone....????:wavey
 

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Possibly a throttle position sensor . But the first thing I would check is the fuel pressure .
 

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I think the diagnostic should be able to tell you, it'll test every single electrical circuit and tell pretty much what is needed. Most don't want to pay for this test, but it's better than stabbing at it in the dark.
 

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That fuel pump relay didn't burn up for nothing, there may be some high resistance in your fuel pump circuit, remember that that circuit does include the fuel pump, which if orginal is 16-17 years old now.

Get your codes again and see if the fuel pump circuit codes are still there. If so, check fuel pressure before you drop the tank so you have an idea if it's low (and it probably is). Then check the voltage and ground right at the fuel pump connector at the tank.

If everything's good there, I'd install a new pump. Be extra careful with the seal and lock ring, they can be sensitive and you can get a fuel leak, also the filler neck grommet gets old and brittle, I'd replace that too if you drop the tank.
 

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Discussion Starter #17
Ok.. I did another test today on my car. I cranked it sitting on a hill...it sat at idle for 10 mins or more. I released the parking brake and as the car started to (very slowly) roll forward the rpm spiked from 800 to around 1300 and the check engine light came on and the engine died. I did this multiple times going forward and reverse. It does the same thing over and over. And just like always...it will sit in one spot and idle till the gas tank is empty. And I was only rolling the car at maybe 3-5 mph on a smooth small incline. :scratchchin

So.. my question is...what sensor (if any) knows when the car is rolling? Or is there even such a thing?... :headscratch:

Any help from anyone who might know what is causing this problem would be much appreciated:happydance:
 

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Discussion Starter #18
That fuel pump relay didn't burn up for nothing, there may be some high resistance in your fuel pump circuit, remember that that circuit does include the fuel pump, which if orginal is 16-17 years old now.

Get your codes again and see if the fuel pump circuit codes are still there. If so, check fuel pressure before you drop the tank so you have an idea if it's low (and it probably is). Then check the voltage and ground right at the fuel pump connector at the tank.

If everything's good there, I'd install a new pump. Be extra careful with the seal and lock ring, they can be sensitive and you can get a fuel leak, also the filler neck grommet gets old and brittle, I'd replace that too if you drop the tank.
The fuel pump relay burnt up because it was sitting directly on the exhaust header. Not because of some bad electrical circuit. And to tell you the truth, I believe it's getting plenty of fuel! When I crank it and revv it up it doensn't starve for gas. Also if I punch it it will run like a scalded dog... It's only when I stop or try to let it idle at low speed that it dies.

Like I said... I recently did a test where I let the car roll down hill (at idle and in neutral) slowly and it will throw a check engine light and die. When sitting still it revs like a monster and sounds like it would drive to Canada. But if I attempt to roll the car...even a foot or two...it will die. And while rolling slow or fast it will attempt to crank, but it dies almost like when I try to crank it.. It cranks and someone cuts off power just as it cranks..and then it dies. But when I come to a complete stop. It will crank back up again.

This makes no rational sense to me. And I wish I could find someone who has had this problem before and knows what sensor is killing the engine. And it's NOT related to vibration or shaking of the car, because I've gotten some friends and we shook the hell out of it front to back and side to side..and it kept running...only to die as soon as I rolled it out of the driveway.

I'M LOOSING MY MIND and I'm about ready to just pour gas on it and watch it BURN!:so
 

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Hang in there Todd, we're pullin for ya. The right person will come along who has had this happen to them or someone they know. I have a problem that when I'm coasting at any speed it idles at 1300. As soon as I come to a complete stop it drops right to 700rpm. Bugs the hell out of me. I've emptied my bag of tricks on this one and just live with it. Yours it much worse.
 
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