2000 Mustang GT help needed

[Hopeless]

It seems there are some Mustang fans here so hopefully someone can point me in the right direction.

About this time of the year when the outside temps get lower, it's hard to get it to start. When it does start it runs rough, on the verge of dieing and will sometimes even die. During this there is an extreme gas smell until it smooths out and idles normally. Anyone have any ideas what could be causing this?

 

[master_shake_]

when was your last tune up?

 

[Hopeless]

when was your last tune up?

For normal stuff (plugs, oil, etc) my wife just takes it to a shop and has it taken care.

This issue has actually been going on for a few years now. It runs great all spring, summer and early fall then about this time of the year when the temp drop the issue returns.

I do know that after this problem began, a "module" was replaced that is located above the front passenger wheel well liner. Have to at least loosen the liner to pull it back to even see it. It still had this issue the following winter.

 

[Raizinman]

I would check fuel pressure at the fuel rail. The 2000 Mustang has had problems with the fuel pump causing the problem you describe.

 

[master_shake_]

i don't think fuel pump.

sounds like flooding.

could be a cracked coil tower and when it gets cold there is moisture causing it to arc.

 

[jlee]

Sounds similar to the Subaru cold weather fuel smell problems.

http://www.bazoomer.com/fuelline/fuelline.html

 

[Hopeless]

i don't think fuel pump.

sounds like flooding.

could be a cracked coil tower and when it gets cold there is moisture causing it to arc.

The way it's acting I was thinking for some reason it was flooding as the extreme gas smell is coming from the exhaust. Then it's almost like the rough idle is because there's still excess gas. It was bad enough once that even with the garage door all the way open had to step outside. Me thinking it's flooding is based on my dad's old pickup he had when I was a kid. It had a carb and if you pumped it more then the magic number of times it would be similar to what this car is doing.

Has me scratching my head since it's only when the weather starts getting cooler/colder and runs just fine the rest of the year. Normally after the first time you start it in the morning it will be fine all the rest of the day. Not to mention I didn't think a fuel injected car could flood out unless the loose nut behind the wheel did something to cause it.

 

[Pacfanweb]

Is this only on cold starts?

Can you crack the throttle open a bit and keep it from stalling?

 

[slag]

Going with coolant temp sensor.

Final answer.

 

[BUTCH1]

Going with coolant temp sensor.

Final answer.

I don't think so, if it were that far out of range to cause driveability issues it would throw a code.

 

[BUTCH1]

The way it's acting I was thinking for some reason it was flooding as the extreme gas smell is coming from the exhaust. Then it's almost like the rough idle is because there's still excess gas. It was bad enough once that even with the garage door all the way open had to step outside. Me thinking it's flooding is based on my dad's old pickup he had when I was a kid. It had a carb and if you pumped it more then the magic number of times it would be similar to what this car is doing.

Has me scratching my head since it's only when the weather starts getting cooler/colder and runs just fine the rest of the year. Normally after the first time you start it in the morning it will be fine all the rest of the day. Not to mention I didn't think a fuel injected car could flood out unless the loose nut behind the wheel did something to cause it.

A FI car's computer will "know" it's a "cold start" situation and enrich the fuel by opening the injectors for a longer pulse width. Nothing you are doing behind the wheel is causing this issue, check and see if the spark plug wires (if it has any) are original, clean your MAF sensor with some spray made for that, check your air filter, is it a clogged mess?.

 

[boomerang]

The way it's acting I was thinking for some reason it was flooding as the extreme gas smell is coming from the exhaust.

Is this a feeling or something you have actually confirmed? In other words you've been outside the car on a cold start on a cold morning and your inspection leads you to the exhaust as the source? No drips, no leaks nothing under the hood spraying fuel?

You need to have a scan tool connected on a cold start as well as a fuel pressure gauge. This should be relatively easy to diagnose if the problem is a consistent one.

BTW, a leaky injector or injectors can cause flooding. Which is what I'm thinking is the problem. I wouldn't suggest replacing those willy-nilly without knowing for sure that they are in fact the problem.

 

[BUTCH1]

Is this a feeling or something you have actually confirmed? In other words you've been outside the car on a cold start on a cold morning and your inspection leads you to the exhaust as the source? No drips, no leaks nothing under the hood spraying fuel?

You need to have a scan tool connected on a cold start as well as a fuel pressure gauge. This should be relatively easy to diagnose if the problem is a consistent one.

BTW, a leaky injector or injectors can cause flooding. Which is what I'm thinking is the problem. I wouldn't suggest replacing those willy-nilly without knowing for sure that they are in fact the problem.

Yea, injectors are not cheap. I agree his next step is to check the pressure on the rail and see how long it holds that pressure after shut down. It should maintain pressure for several minutes after power off, if it drops rapidly your looking at a leaking injector or bad pressure regulator. It might be possible to pinch shut the fuel line ahead of the regulator to see if that's causing the loss of pressure. After that OP would need to remove the injectors and fuel rail from the manifold and place a clear plastic bottle on the outlet of each one then power up the fuel pump, if he see's fuel dripping into one of the bottles the problem is located. OP also keep a close eye on your oil level and it's smell, if it's a leaking injector issue fuel could leak down the manifold and into an open intake valve and find it's way into the crankcase. This would thin out the oil and ruin the bearings and/or rings.

 

[justin4pack]

Does your mustang have a v 6 in it

 

[BUTCH1]

Does your mustang have a v 6 in it

No, it's a GT.

 

[wabbitslayer]

Sounds like the IAC valve is sticking. It's right on top front of the intake on the 4.6L; had to replace mine on my 01GT at 50k miles and then again about 120k. If you are stuck somewhere, GENTLY tapping it with a hammer may get it to unstick, just make damn sure you know what you are tapping on.

Here is a video purporting to show how to "clean" one:
https://www.youtube.com/watch?v=DjQ3eptiirI

but my research all said "cleaning" one was useless. My experience bore that out, I "cleaned" mine and it still kept sticking. They aren't that much to buy another. But the video above should show you what you're dealing with.

 

[slag]

I don't think so, if it were that far out of range to cause driveability issues it would throw a code.

Would it? I don't have OBDII experience with coolant temp sensors, only OBDI with an old car I had.

What code gets thrown for a coolant temp sensor out of spec, P0118?

 

[master_shake_]

Would it? I don't have OBDII experience with coolant temp sensors, only OBDI with an old car I had.

What code gets thrown for a coolant temp sensor out of spec, P0118?

• P0115 Engine Coolant Temperature Circuit Malfunction
• P0116 Engine Coolant Temperature Circuit Range/Performance Problem
• P0117 Engine Coolant Temperature Circuit Low Input
• P0118 Engine Coolant Temperature Circuit High Input
• P0119 Engine Coolant Temperature Circuit Intermittent

http://www.totalcardiagnostics.com/...of-obd-codes-generic-obd2-obdii--manufacturer


on start up though fuel is managed by the pcm and does not depend on oxygen sensors for adjustments until closed loop.


so if it's cold start issues and the temp sensor was bad the MIL would come on and the reading would be -40C

 

[Hopeless]

Thanks for the responses.

Before, during or after this happens the check engine light does Not come. So I haven't attempted to pull any codes.

The issue only happens when the outside temps go down, had some overnight lows in the mid 40's. After getting it to start and wait until the idle smooths out it's fine to drive. Also any other time it starts and drives just fine.

As far as some of the questions asked the temps have came back up the last bit so I'll have to wait for them to drop back down to get any info. I only have basic hand tools so I'm kind of limited on what I'd be able to do.

Wouldn't some of the things mentioned, like a leaking injector for instance, cause some kind of problem all the time? Because as long as the weather is in the 60's (maybe 50's) or above it is completely fine.

 

[boomerang]

Wouldn't some of the things mentioned, like a leaking injector for instance, cause some kind of problem all the time? Because as long as the weather is in the 60's (maybe 50's) or above it is completely fine.

My thoughts are that the internal seals are affected by the cold. Remember when the Shuttle solid rocket booster exploded with the root cause being the o-rings between the sections being adversely affected by the cold temps that morning?

That's a pretty dramatic example and it shouldn't be taken as defacto proof of why I'm thinking what I'm thinking. A fuel pressure gauge connected would go a long ways towards diagnosing this. At key up, the pump should run pressurizing the system and it should hold pressure. You'd want to do that when it's cold.

There is no shame in paying people to do what they do for a living IMO. If you don't have the tools you need, take it in somewhere.

 

[NaughtyGeek]

There is no shame in paying people to do what they do for a living IMO. If you don't have the tools you need, take it in somewhere.

You have to be careful where you take it for a problem like this however. Not all, but most dealerships are going to check for codes and in their absence just start replacing parts until they get to the problem. If I were the OP, I'd find a local shop that does engine tuning. They will have the proper logging software to see exactly what is going on during startup and will likely be able to point you to the proper component. That also begs the question, is the car running a stock tune or is there a canned aftermarket tune in there. It's not uncommon for canned tunes to cause issues like this.

 

[LTC8K6]

Sounds like the IAC valve is sticking. It's right on top front of the intake on the 4.6L; had to replace mine on my 01GT at 50k miles and then again about 120k. If you are stuck somewhere, GENTLY tapping it with a hammer may get it to unstick, just make damn sure you know what you are tapping on.

Here is a video purporting to show how to "clean" one:
https://www.youtube.com/watch?v=DjQ3eptiirI

but my research all said "cleaning" one was useless. My experience bore that out, I "cleaned" mine and it still kept sticking. They aren't that much to buy another. But the video above should show you what you're dealing with.

My Taurus was acting up in the cold too.

Read the suggestion about giving the IAC valve a rap while it was stumbling.

I waited for it to idle poorly one cool morning.

Sure enough, when I whacked the valve it began to idle perfectly.

 

[RLGL]

Yea, injectors are not cheap.

They are if you get them at the right place. I have had excellent results with cleaning and replacements from South Bay Fuel Injectors out of NYC.

 

[JEDIYoda]

As of now, this very moment what we do know is that something is wrong with your car!!

 

[master_shake_]

As of now, this very moment what we do know is that something is wrong with your car!!

your powers of deduction...

are you columbo.

blink twice if yes.

:sneaky:

j/k

does the idle race when you start it?

nvm re-read the op.

what is your intake manifold made out of?

plastic or aluminium?