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Discussion Starter #1
FIRST AND FOREMOST! My mechanical skills are what could be classified as "limited" and with that so are my diagnosis skills!
With that said, I have an 03 which I baby: Only the best for her!
I ONLY run 93 in her, and at 3.88 a gal? Who wants to waste! Recently Ive started to notice a STRONG fuel smell. And Ive notice RIGHT upon start up (and while driving too, its just easier to narrow down on start up) if at the exhaust of the car, it INSTATLY smells like a fuel dump. It honestly smells like 3.44 a sniff! Like I'm dropping straight 87 out the @$$!! I do NOT know if "incomplete fuel burn" is my problem or not, its just the first thing that popped into my head! And with my lack of knowledge I was thinking some higher end plugs and wires might make for a better burn? Or I could be COMPLETELY on the wrong track?
Any suggestions?
 

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First, are the any DTC (check engine) codes? I'm assuming there are not or you would have mentioned them.

Next, it's common to smell fuel on initial start-up. Why? Because of the way the cam sensor works, the engine must make two relevolations before the PCM knows which stroke the motor is on. Because of that, the PCM fires the fuel injectors on every stroke. This doubles the amount of fuel being used. Which is OK because the rich mixture helps with starting.

The effect of this is a fuel smell right after start-up. This should go away once the motor warms.

If it does not, then there are issues. Let me see if we can help.

My first $$ saving suggestion, switch to a name brand regular gas. If your car is not tuned for preimum, then running higher octane is a waste of $$. Now if the car has been modifed and needs the extra octane, then that's different.

Next, take the car to your local autoparts store and have the alternator tested for output and excessive AC ripple. Have the battery tested as well.

What about the battery cables? Clean and tight? Any Corrosion cauliflowers? Don't cut corners here. Today's cars can not run right without a strong battery and charging system.

Next, clean the MAF sensor. Use only a product designed for the job.

Check for vacuum leaks. Replace any vacuum hoses that are rotten, soft, or hard and brittle. Change the PCV value. Check to be sure it's sealing well in the valve covers.

When was the last time the fuel filter was changed?

Regarding spark plugs, IMO for a street driven car, high end plugs don't really buy you much. It's more important for the plugs to be clean and correctly gapped.

Stick with factory recommended plugs. Others may disagree. <puts on flame suit>

Let's see if these have any improvement.
 

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Discussion Starter #3
There IS one code, and it was completely self induced!
Its for the cats.
I gutted the cats when I was first got the car when I was 18
Thinking it would make it sound meaner and air flow a little better
Young and dumb right?
I have for many years since contemplated replacing the cats, but just never got around to it!
I guess I probably should have thought of that myself?
I scan my car about once a week and delete the cat code (it pops back up after about 5 days... or one harsh running day)
I guessing with the info I forgot to mention could very well be my problem?
Should I follow aforementioned steps as well just for insurance?
 

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A DTC associated with the rear cats will not affect driveability.
 

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Discussion Starter #5
So it being my gutted cats is NOT the problem?
GOOD! I didnt wanna fix 'em right now anyway!:kooky:
So I'm gonna follow the steps you have given me, and I will report back by the begining of next week! Thanks
 

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Have you pulled your plugs and look at them. I know this may sound wierd but if the car is running lean you can also get the same fuel smell. As for plugs I run autolite 103 these cars seem to love 1 stage colder plugs. I pick up about 3 rwhp on back to back dyno pulls just by changing plugs
 

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IMO, the best value for your $$ is stock parts for a street driven car.

Do you have any reason to believe that your COP's are actually bad? No DTC codes right?

If this were my car, new plugs along with the reset of the standard "tune up" items.

If this is a high mileage car, consider new front O2 sensors as they will improve mileage. IMO, new O2 sensors will give a better bang for the buck instead of aftermarket COPs. Especially when it not known there is even a problem with the ones you have.

Go from there if there are still concerns.
 

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I agree stock cops are the best. I would change the boots though if they havent been done in a while.
 

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i still have my oringinal stock coils from 1999 on a stroked 500 hp kenne bell car, no need for anything different. how is the car running besides the smell of fuel?
 

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Discussion Starter #11
i still have my oringinal stock coils from 1999 on a stroked 500 hp kenne bell car, no need for anything different. how is the car running besides the smell of fuel?
Car runs great actually. Bat terminals are basically brand new looking. Bat itself only has a handful of miles on it.
The alternator however isnt putting out the amps it should. It only registers 76 istead of the 110 factory. Looking at getting a new one soon. Possibly the root of all my issues?
 

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A bad alternator diode is well known to cause cam sensor problems. What happens when the PCM doesn't get a good cam signal? If fires the injectors on EVERY stoke. Double fuel. Terrible gas mileage. Fuel smell in the exhaust?

However, there is usually a DTC code.

Today's cars can not run right without a strong charging system and battery. Low alternator output is a sign of a bad diode. Excessive AC ripple is another symptom.

IMO, for vitually any under the hood car problem, the first assesment should be of the charging system. Only then can the other tests be performed in confidence. Remember the basics.

If $$ is tight, consider getting a salvage yard alternator. The 4.6's alternator is stupid easy to change. I have changed several in a parking lot with using only a basic set of socket's and 10 minutes. I have had $40 salvage yard alternators last 5 or more years.
 

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Discussion Starter #13
Never changed an alternator myself, but it seems straight forward! Finding a junked 4.6 in this place is almost too easy! Whether they alternator is there or not is the question! I'll do some research, see what I can find. And return with hopefully good news!
 

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Discussion Starter #14
100% brand new, non-remanufactured alternator installed today. No difference in the extreme pungent fuel smell even after about 50 miles...
 

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WOW. Only suggested to have the alternator tested. This does rule out the bad diode as a possible cause.

Just for the record, you are aware without cats, the exhaust will have a stronger smell.

Have you cleaned to MAF?

Have you checked for vacuum leaks?

Have you checked for moisture in the spark plug wells?

Do you have any exhaust leaks?

Have you pulled the plugs and inspected them? Replace them with factory or high end plugs, your choice.
 

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Discussion Starter #16
The alternator wasnt SHOT, but it's ampage was low, so I replaced it anyway! I took it to a friend who owns a shop and ask him to overlook it for leaks, anywhere, vacuum seals, exhaust, fuel lines, everything. Came up nothing. Havent pulled the plugs, was intending to go ahead and upgrade plugs if I pulled them anyway.
 
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