Lean/Rich Question

Trail of Dead

New Member
Aug 6, 2006
43
0
0
England
Hi all, I'm new to the board here. I just got my first Mustang last week 1999 GT 5-speed, Performance Red w/Blk interior, optional 17's, Flowmasters, 102,000mi, new clutch, new tires, all in all a very clean car. The car is originally from the Ft Lauderdale/Miami area and since I got it I have noticed that I can smell gasoline kinda strongly while driving it and it kinda stutters a little when first changing gears, almost like it's getting too much gas and choking some until the rpms go up(reminds me of my old 351W) and I got to wondering what is causing this(my 351 smelled like a crapload of gas cause it was bored .010 over had a Edelbrock RPM intake a Holley 750cfm 4bbl and a stock cam.....it's the stock cam that caused the prob). I live in S. Georgia (Moody AFB) and got to thinking MAYBE it might have something to do with some sort of lean/rich calibration that may have been done to it since it is originally a Miami car and being so close to sea water/lower elevation. It has a SQUEAKY clean carfax, regular maintainance, is this something I can have the Ford garage calibrate for an arm and a leg? or is it something I can do in my driveway? Don't get me wrong it runs great, very strong, but this one thing is pi$$ing me off a little :nono:
 
Thanks for the quick replies, svttech sorry about posting the thread in the wrong forum....I forgot I was in "4.6 Talk" when I made the thread. As for a gas leak, I haven't spotted any wet spots on the car port's floor. It smells like gas all the time, and it "shudders" mostly in the start of a gear and only when the accel pedal is pushed about 1/4" approx. When it first started happening my first reaction was "Damn, must have some water in the gas......" which I suppose I still haven't ruled that out, I haven't used dry gas yet, and I haven't ran the tank empty....please more suggestions, you guys are great. Oh, and just yesterday at the base (Moody) I was putting 87 in the tank and around a '01-'04 GT pulled up to put air in his tires, at first I had to do a double take. I said to my wife "Thats a GT,.......HUH? Wait, sorry honey, I think that's a V6, no wait it IS a GT......he must be running stock exhaust." So, I finished puttin' fuel in it and started my GT and as soon as the flowmaster grumbled to life he started looking in our direction. I drove past him and he smiled and we gave each other the :nice: gesture. It was cool. Sorry, a little off topic but I had to share my first Mustang experience with you all. :cheers:
 
sounds like you have a hell of a misfire there. smelling gas like that is not a good thing.. Pull the dipstick out and see if the oil is diluted with fuel.. This happens a lot on really bad ignition related misfires because the unburned fuel washes down into the oil, making the condition even worse becuase of the fuel vapors in the PCV system richen the rest of the cylinders.. Plus the diluted oil can lead to spun bearings.

first check to see if there is fuel in the oil, then you can replac ethe plugs and hope the coils are ok.. At work I can use the power balance test programm in the IDS/WDS scan tool and tell you what cylinder is misfiring but without that tool this is just a guessing game..

If you do attempt to fix this yourself I wouild go about it this way.

1. replace all the spark plugs, change oil and filter ( with the way your describing the fuel smell I have no doubt that there is fuel contamination in the oil)

2. see if the engine runs smooth or if it still misfires. If it still is missing you can try pulling the connector off the coils one cylinder at a time untill you notice it runs the same when you pull the connector..
 
Svttech, I went out and did as you said, sure enough, the oil smelled of gasoline. A couple of days ago I went to Advanced Auto and got a K&N Performance Gold oil filter, just have to wait till the 15th to get the oil and some slick 50. I usually run Valvoline Max Life in my '98 Blazer, the 4.3 seems to like it. What kind of oil do you guys recommend for the 4.6? I remember in my Yamaha Banshee only Klotz would do, it made it run like a raped ape....is there any oil on the market that can achieve similar results in a Mustang? Also, I planned on running Bosch Platinum +4's, any cons to these new Bosch's? Right now it has the stock air intake, no funds YET for a BBK replacement, so as far as OEM type replacment filters what do you guys suggest? I'm driving her to Pennsylvania in a few weeks and want to get it in tip top shape for the 1000mi one way trip. Again, thank you ALL for the quick replies :nice:
 
Bosch Bad! I had them in my car. I started noticing a studder or hesitation so I pulled a plug. The center electrode was gone. I think they were dbl platinums, I have a buddy that works at advanced he says they do that alot. Not sure why but I will not put them back in my american car. I am a recovering Volkswagen driver and thats what I always used in the many VWs I have owned. They liked them, my mustang chewed them up and spit them out. just my .02$ -atari
 
svttech76 said:
sounds like you have a hell of a misfire there. smelling gas like that is not a good thing.. Pull the dipstick out and see if the oil is diluted with fuel.. This happens a lot on really bad ignition related misfires because the unburned fuel washes down into the oil, making the condition even worse becuase of the fuel vapors in the PCV system richen the rest of the cylinders.. Plus the diluted oil can lead to spun bearings.

first check to see if there is fuel in the oil, then you can replac ethe plugs and hope the coils are ok.. At work I can use the power balance test programm in the IDS/WDS scan tool and tell you what cylinder is misfiring but without that tool this is just a guessing game..

If you do attempt to fix this yourself I wouild go about it this way.

1. replace all the spark plugs, change oil and filter ( with the way your describing the fuel smell I have no doubt that there is fuel contamination in the oil)

2. see if the engine runs smooth or if it still misfires. If it still is missing you can try pulling the connector off the coils one cylinder at a time untill you notice it runs the same when you pull the connector..


SVTTECH, i have the same problem with my car. it bogged down a lot then i replaced the spark plug on the 3rd cylinder and that took care of the studdering but i still run rich on the right bank. it blows out white smoke out of the exhaust which i am thinking may be a head gasket leaking water into my cylinders. also when we pulled the sparkplug yesterday because the check engine light came back on and it said the same codes as before, there was it looked like a mixture of dirt and oil in the actual tube where the sparkplug sits..... NO clue how that happened. any suggestions? i am about to take it to a shop but i dont have the money to throw around.
 
Trail of Dead said:
Svttech, I went out and did as you said, sure enough, the oil smelled of gasoline. A couple of days ago I went to Advanced Auto and got a K&N Performance Gold oil filter, just have to wait till the 15th to get the oil and some slick 50. I usually run Valvoline Max Life in my '98 Blazer, the 4.3 seems to like it. What kind of oil do you guys recommend for the 4.6? I remember in my Yamaha Banshee only Klotz would do, it made it run like a raped ape....is there any oil on the market that can achieve similar results in a Mustang? Also, I planned on running Bosch Platinum +4's, any cons to these new Bosch's? Right now it has the stock air intake, no funds YET for a BBK replacement, so as far as OEM type replacment filters what do you guys suggest? I'm driving her to Pennsylvania in a few weeks and want to get it in tip top shape for the 1000mi one way trip. Again, thank you ALL for the quick replies :nice:


DO not continue to drive this car with diluted oil.. you have a bad misfire and this needs to be fixed. I don't care what you use for oil ANYTHING is better than fuel diluted oil. You could spin a bearing running it the way it is now.

get some regular motorcraft plugs and change the plugs and oil at the same time. If you do not change the oil at the same time you will foul out the plugs again and possibly still have misfires.

So regular plugs and new oil and filter, when you pull the plugs put a drop of oil or two down each plug hole.. remember only a tiny amount of oil. this is so you get a good ring seal, fuel diluted oil washes down the rings and they wont seal right, when that happens you will still have a misfire untill oil builds up around the rings.

If after all of this you still have a misfire then we need to figure out what coil went bad on you too.
 
Thanks svttech, I actually haven't drove it since I smelled the gas in the oil, I actually remember my dad's '47 Dodge Powerwagon doing this. Well, I get paid on the 15th, and am just going to run the Valvoline Max Life that I always use, as for the motorcraft plugs Platimun or no Platinum? The wife and I are going to take it to the nearest Ford garage, and have them change the oil,plugs,PCV,Fuel Filter, and the air filter....I hope it don't cost an arm and a leg. But per your advice the pony will have to rest for awhile........I'll keep you all posted, I hope when I get it straightend out this blog will help others! :cheers:
 
I just got off the phone with the local Ford garage and they quoted me $450-600 "depending on what it needed"......my jaw dropped and I asked "well, how much for just an oil change & motorcraft plugs?" He said around $200. I asked him if I could buy Motorcrafts at an auto zone or other retail store and he said Autolite's are the same, so, I found Autolite Dbl Platinums are $3.99 (pack of 2), Fuel Filter is $7.99, PCV is $1.59, Fram Extra Guard Air filter is $18.49, and I already have a K&N Performance Gold Oil Filter "at the ready".....just got to get the oil! I am curious though since my car was missing it's owners manual....where is the fuel filter located? In my old S-10 it was on the firewall, but I couldn't find it anywhere in the enginebay on the 'stang. I live on Moody AFB, and we have a "hobby shop" so, for $6.00 I have access to a hydraulic lift, and for $2.00/hr I have access to all the tools I could possibly need.....HUAH! (Prior Army)
 
if you get bosch get the regular plats... the +2 and +4 are actually WORSE for the car... get some NGK plugs and run Mobil1 oil or Castrol Syntec... i personally like Syntec but its up to you. also take the car to advance and se what codes you pull.
 
One thing that wasnt mentioned...

You said you have Flowmasters, but do you have a catless crossover (midpipe) pipe?

Running one of those can creat a gas smell due to no cats cleaning the exhaust up.

As far as the oil, I havnt seen a car with oil that does not have a scent of gas in it. Not neccecerily a strong one, but one none the less.

Definatly not disagreeing with svttech, but I thought I would throw out the offroad midpipe suggestion out there.
 
Thank for the repsonses, Actually it has an H pipe on it, 2 cats......02 sensor looks fairly new. When I first got it, it had more power than it does now......I'm sure the plugs need changed.....Castrol Syntec eh? How much is it per quart? I was thinking about using a synthetic, just don't want to use the wrong brand! I wish I new what the previous owner used. The base sells "Royal Purple", I don't know anything about it. Thanks for ALL your help fellow members of the blue oval brigade! :hail2:
 
Fuel filter is on the passenger side of the engine bay i believe, close to the firewall.

Dealership quoted me 100 dollars to change the plugs, fuel filter, and do a tune up... got there and the price turned into 350 because my engine has coil on plug design. I guess its the only 2000 4.6L mustang gT with COP right lmao... i drove home, took an hour and a half out of my day and changed the plugs myself. Spent 20 bucks and got mr. lube to change my fuel filter. Yeah if you have an offroad H your car will smell like a skidoo. Alternatively if your used to a 351 you might not be aware that these cars don't make their power until 3000rpm+...

Oh and i used NGK plugs, the ones with the tiny platinum tip... G power or something.