running to rich?

[icer]

I was at work yesterday (a marina) and when I was leaving one of the mechanics stopped me and when I was talking to him he said my car was running rich cause he could smell it. I have no idea what he is talking about, anyway is there a way to check to see if my car is running rich, if so how do I fix it?, is it the MAS, o2 Sensor, etc.

i got a :
1991 240sx SE
104,000 mls
injen short ram air intake(only mod)

[mr0072003]

He meant your burning to much fuel...No to sure how to fix it, but that is what he meant.....get your timming checked and plugs checked, thats a start..
good luck

Peter 95 SE

used to own a  92 SE

[DuffMan]

Check you ECU for codes. The most common things that will cause a car to run rich are the O2 sensor and engine temp sensor.

[Natty]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (DuffMan @ July 24 2002,05:31)</td></tr><tr><td id="QUOTE">Check you ECU for codes. The most common things that will cause a car to run rich are the O2 sensor and engine temp sensor.</td></tr></table><span id='postcolor'>
Yes, these are good ideas. When you pull the plugs to be replaced, note how they look at compare with the guide at www.pdm-racing.com
Is there black exhuast smoke when you mash the gas pedal? Put your finger in the muffler (after it is cooled for a couple hours &nbsp;:!: &nbsp;) and note if there is a black soot in there.
But I bet your ECU threw a code for the o2 or coolant remp sensor.
Good luck.
Jeff

[icer]

no black smoke, and right now i can't get the old spark plugs out, because the old spark plug wire boots are stuck down there.

[icer]

any other ideas?

[Yosho]

If the mechanic said he thought your car smelled like it was running a rich then he meant that it had a rotten egg smell.

Do you notice ANY smoke comming out of your exhaust? &nbsp;Blue-Grey/White/Black?

[S13Grl]

rotten egg smell?<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'> running rich means burning too much fuel. burnt fuel smells nothing like rotten eggs.

You may want to check your fuel pump and filter. The boots from your old spark plugs should be easy to pull once the motor has cooled off. Rubber contracts once cold, make sure it's really cool before you try and fight with it again. if that doesn't work, then just take &nbsp;your valve cover off <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>. You'll have more leverage.

[ibanezxguy]

yeah make sure its cool today i just got 2 degree burn... damn it hurts like hell..... im stupid... &nbsp;running rich its bad.. ive tried everything to fix it but i still think im running to rich.... you will just get less miles per tank

[bbp]

the rotten egg smell is often the cat.

[Yosho]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (S13Grl @ July 25 2002,6:57)</td></tr><tr><td id="QUOTE">rotten egg smell?<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'> running rich means burning too much fuel. burnt fuel smells nothing like rotten eggs.

You may want to check your fuel pump and filter. The boots from your old spark plugs should be easy to pull once the motor has cooled off. Rubber contracts once cold, make sure it's really cool before you try and fight with it again. if that doesn't work, then just take your valve cover off <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>. You'll have more leverage.</td></tr></table><span id='postcolor'>

Actually, running rich means having too much excess fuel for a full burn in the combustion chamber (not too much burnt fuel - it's the actually the opposite - unburnt fuel). If you're running really rich, that excess fuel won't be completely burnt and you may have black smoke and a rotten egg smell. Running really rich over a long period of time will usually damage the cat.

Edit: &nbsp;Car engines aren't 100% efficient all the time, so it's normal to have some fuel that goes through unburnt. &nbsp;That's why we have smog... &nbsp;<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/hehe.gif" border="0" valign="absmiddle" alt=':hehe:'>

[tkrolo]

My car has been running rich for a couple months now. &nbsp;Replaced tps, cts, cap and rotor, pcv valve, and 02 sensor. &nbsp;Even tried adjusting timing to compensate. &nbsp;Would a bad cat cause the ecu to sense a bad 02 sensor? &nbsp;Just wondering because it is still giving me the 02 code. &nbsp;If so that would cause the ecu to read incorrectly causing the overabundance of fuel, right?!

[S13Grl]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Yosho @ July 27 2002,01:45)</td></tr><tr><td id="QUOTE"></span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (S13Grl @ July 25 2002,6:57)</td></tr><tr><td id="QUOTE">rotten egg smell?<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'> running rich means burning too much fuel. burnt fuel smells nothing like rotten eggs.

You may want to check your fuel pump and filter. The boots from your old spark plugs should be easy to pull once the motor has cooled off. Rubber contracts once cold, make sure it's really cool before you try and fight with it again. if that doesn't work, then just take your valve cover off <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>. You'll have more leverage.</td></tr></table><span id='postcolor'>

Actually, running rich means having too much excess fuel for a full burn in the combustion chamber (not too much burnt fuel - it's the actually the opposite - unburnt fuel). If you're running really rich, that excess fuel won't be completely burnt and you may have black smoke and a rotten egg smell. Running really rich over a long period of time will usually damage the cat.

Edit: Car engines aren't 100% efficient all the time, so it's normal to have some fuel that goes through unburnt. That's why we have smog... <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/hehe.gif" border="0" valign="absmiddle" alt=':hehe:'></td></tr></table><span id='postcolor'>
When you're running rich, your combustion chamber gets a lot of fuel. Because there is still a spark present, it gets burnt, but it's an inappropriate mixture, so it smells funny and the car runs funny. You'll get fuel deposits all over the place because of the excessive amount that you're burning/consuming. I can't say I've ever heard of any fuel go through a motor head unburnt when there is spark.

[NichiSan]

OK, so I think I am running rich. How do I make sure of that and how do I fix it? Maybe timing? I know that changing the O2 sensor would be (maybe) recommended, but I don't want to change stuff that doesn't need changed. How do I figure out before I start changing stuff what is the cause ?

thanks, as usual.

[nissan&#39;s_fury]

Would bad/old gas make an engine run rich? &nbsp;I am currently haveing this problem with my sr. &nbsp;It only does it when i try to start it &nbsp;but after i do getit started it doesnt do it as bad.

[turbo240sx]

check the voltage on the throttle position sensor on you throttle body. it should be at .45-.50 volts stock. i checked mine it was at .68volts. turned it down to ..43 volts and it runs better no more rich smell or black smoke coming out of the fart can.

[rps13 SR]

Originally posted by S13Grl
</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Yosho @ July 27 2002,01:45)</td></tr><tr><td id="QUOTE"></span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (S13Grl @ July 25 2002,6:57)</td></tr><tr><td id="QUOTE">rotten egg smell?<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'> running rich means burning too much fuel. burnt fuel smells nothing like rotten eggs.

You may want to check your fuel pump and filter. The boots from your old spark plugs should be easy to pull once the motor has cooled off. Rubber contracts once cold, make sure it's really cool before you try and fight with it again. if that doesn't work, then just take _your valve cover off <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'>. You'll have more leverage.</td></tr></table><span id='postcolor'>

Actually, running rich means having too much excess fuel for a full burn in the combustion chamber (not too much burnt fuel - it's the actually the opposite - unburnt fuel). _If you're running really rich, that excess fuel won't be completely burnt and you may have black smoke and a rotten egg smell. _Running really rich over a long period of time will usually damage the cat.

Edit: _Car engines aren't 100% efficient all the time, so it's normal to have some fuel that goes through unburnt. _That's why we have smog... ?lt;img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/hehe.gif" border="0" valign="absmiddle" alt=':hehe:'></td></tr></table><span id='postcolor'>
When you're running rich, your combustion chamber gets a lot of fuel. Because there is still a spark present, it gets burnt, but it's an inappropriate mixture, so it smells funny and the car runs funny. You'll get fuel deposits all over the place because of the excessive amount that you're burning/consuming. I can't say I've ever heard of any fuel go through a motor head unburnt when there is spark.

rps13 sr: there can be a spark and unburned fuel!! when that happpens thats running rich.. its like you have a certain amount of air coming in and too much fuel for it even when it sparks you dont have enough air to feed the fire but you got too much fuel. that would cause the fuel to come out the exhaust and through the cat... and the o2 sensor.. too rich can mess up the o2 sensor... so i'm saying that fuel doesnt have to be burnt when there a spark present cause your running too much fuel for the air thats comin in.. now if you didnt have enought fuel and too much air then that will be a big problem caues then you will start to knock. and soon after that depending how lean your runnin your engine will die slowly orr go boom and just die lol
sorry if what i wrote is confusing hehe

[kalieaire]

Originally posted by tkrolo
My car has been running rich for a couple months now. Replaced tps, cts, cap and rotor, pcv valve, and 02 sensor. Even tried adjusting timing to compensate. Would a bad cat cause the ecu to sense a bad 02 sensor? Just wondering because it is still giving me the 02 code. If so that would cause the ecu to read incorrectly causing the overabundance of fuel, right?!

It depends, if you're driving a USDM S14, you have obd2. However, if you're driving an S13, you will have OBDI.

The difference between the two is that OBDI, you could run w/ or without a cat and it wouldn't make a damn difference to the ECU.

For an OBDII equipped machine, there's an o2 sensor that is after the cat. If your cat is fux0red in an OBDII car, then the after cat O2 sensor will see that and tell your ecu that you've got problems. Usually this won't affect your driving or performance, but it will give you a CEL.

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Running rich can be a variety of problems, bad mafs, iacv weirdo, dirty air filter, bad timing, injectors that are stuck wide open, crappy plugs, crappy plug wires, crappy distributor cap and/or rotor, injector wiring grounded where it's not supposed to be, vaccuum leaks, egr valve opened when it's not supposed to be, your gas being too high of an octane.

there's a zillion different reasons.
----------------

what kind of mileage do you have?

Have you notice your idle being a little unstable, and how about your engine power? Does it have as much power as it used to?

[kalieaire]

When you're running rich, your combustion chamber gets a lot of fuel. Because there is still a spark present, it gets burnt, but it's an inappropriate mixture, so it smells funny and the car runs funny. You'll get fuel deposits all over the place because of the excessive amount that you're burning/consuming. I can't say I've ever heard of any fuel go through a motor head unburnt when there is spark.

I've actually had the unfortunate experience of having my engine run waaaaaaaaaaaay too rich in which i would get ~10 mpg or less, and the idle would be super crappy and you can see gasoline mist wafting from my tail pipe.

Surprising how the plugs weren't fouled.

Yeah, this was caused by a crappy engine harness on my KA24DE. Basically the fuel injector harness was ground on the wrong section. Needless to say, it sucked.

------------
Yep, too much gas will make your engine idle badly. Essentially you're choking it w/ too much fuel, so the idle will be lumpy.

However, richness issues can be very mild to be very severe(smooth running vs constantly dying motor).

Though, there is something to be said about running rich in turbocharged motors, it's always safe(and be rich) than sorry(blowing up cuz you were too lean).
------------

Furthermore, since there is "never", and I use that term loosely, a correct mixture, there will always been unburnt fuel leaving the engine, it's the law of definite proportions.

You know in high school chem, that law that states that all chemical reactions require an exact proportion of atoms to complete a reaction. yeah.


-----------------------------------------------
other problems with an engine running too rich are o2 sensor getting fouled and not being able to give an oxygen reading, your catalytic converter getting fux0red because there's carbon buildup on the elements that are supposed to get superheated, bad mileage, big black stain on your rear bumper, getting assraped by the smog station, small stuff like that.

[95se]

My car has been smelling like its been running rich for over a year now. Started just after the 60K tuneup. I took it to two different mechanics but they say everything checks out. No codes and they can't smell the propane smell. I can and it smells bad. I notice it more so when the driver's side window is down and during moderate acceleration. The first place I took it to said the cat might have gone bad by topping off. Well I replaced that and it didn't do a thing. What now?? Any suggestions. Car is a '95se but it only has 67,000miles on it.

[kalieaire]

First of all, Running rich will NOT Give you a propane smell.

Gasoline and Propane are two different hydrocarbons entirely.

Propane is a colorless, odorless, flammable gas at standard temperature and pressure.

If you smell propane from tanks or methane from your stove, that's not the gas you're smelling, it's the additive the gas company or propane distributors put in so you know when there's a gas leak.

----

If your exhaust smells like it's running rich, it could be that your car is really running rich, or that you've got an exhaust leak before your catalytic converter.
----

If your exhaust smells like rotting eggs, it's possible that your catalytic converter has a problem, but if that were true, your OBDII O2 sensor would pick that up and alert you immediately with a CEL.


------

If your car is indeed running rich, it could just be running minutely rich. This is fine as this tells you that your engine is performing well. Over time, your MAFS Sensor may become gunked up with blow by, or other impurities that pass through the air filter reducing its effectiveness. Also, the O2 sensor inside your header could slowly be succumbing to old age and carbon build up, this also could cause your engine run a little richer.

Another possibility is that your injector seals are a little worse for wear and are leaking extra amounts of fuel down into your throttle body increasing the decreasing the air fuel ratio and increasing the fuel to air ratio.

These are all possibilities, there are many more. Until it becomes a question of engine performance(such as unstable idle, horrible gas mileage), perhaps these problems really don't need to be looked in to.

[95se]

Unfortantely it smells bad and I can't drive more than an hour at a time. No one has figured it out. They say it doesn't have any fuel leaks. It only takes like 5 minutes to start and my interior smells like it all the time. The only thing I can think of is that maybe i need to get it out on the highway more and run it up to speed for some distance since most of the driving i do is city (10minute trips). I have used fuel additives in the past but haven't since this started.

[Yoshi]

Icer and Nissan's Fury, and 95SE,

did any of you guys fix your running rich problem?

I've been having the same issue intermittantly, and am getting pretty ****ed off about it. It's getting expensive, trying to guess what the culprit is, but this thread was very helpful in giving me new ideas and things to check.
*sigh*

[95se]

No. but its gotten worse.

[Steeles]

this wont apply to everyone here but my smoking I narrowed done to bad oil seal in the turbo. so I got a bottle of STP oil additive, (suuposed to enrichen oil rejuvinate seals etc. etc. ) figured it couldnt hurt. poured it in and drove around for awhile went home changed the oil and viola! no more smoking. cist. 3.99 plus an oil change. dunno but its an idea for you guys to try that wont hurt your wallet to much

[rps13 SR]

Originally posted by mr0072003
He meant your burning to much fuel...No to sure how to fix it, but that is what he meant.....get your timming checked and plugs checked, thats a start..
good luck

Peter 95 SE

used to own a &nbsp;92 SE

not that ur burning to much fuel but ur ecu is sending too much fuel or your not burning all the fuel in the cylinder(s) because the timing is off or spark plugs are old and doesnt ignite all the fuel

[jsr20det]

Bringin back an old and helpful thread.

I am running way to rich also, I get about 5-8 miles a gallon. The instant I turn on my car, an almost hiroshima like black smoke cloud erupts from my exhaust, and you can smell the gasoline from afar. I replaced my plugs, and o2 sensor, and I still dont know wats wrong. A friend of mine told me its a fuel injector or head gasketb problem, but I hope it nothing that serious. Im gonna do check the voltage on the throttle body and hope thats it.

Has anybody found out their problem yet?

[xrockoutx]

I've got a 95 ka (supposedly) in a 91, filter, and catback exhaust. Car's from florida and now in nevada. It takes FOREVER to get my car to start up...and it idles like pure **** for the first 5 minutes until it's warmed up. It's running ridiculously rich. Any suggestions as to where to start looking? No codes are being thrown either.

[Matt_240]

bringing back an old thread again dammit. my cars running super rich. so much so that it bogs like hell.

heres a list of things checked so far:
1. changed spark plugs
2. switched out spark plug wires
3. changed rotor and cap - distributor
4. switched out air intake temp sensor
5. switched out MAF
6. checked intake piping for leaks
7. checked all vacuum lines
8. removed egr - to get rid of a lot of vacuum lines
9. tested continuity from sensors(tps,MAF,Intake air, coolant temp) to ecu
10. changed tps - adjusted it
11. changed o2 sensor
12. made more ground
13. switched out ecu
14. changed fuel filter

if any of you guys came up with a solution id like to hear it cause in this whole thread, no one seems to have come up with a solution.

[nightwalker]

how about listing your mods too? man I hate resurrected threads.

[Matt_240]

mods? just auto to manual conversion, exhaust and air filter. i hate resurrecting threads too but for every single thread discussing bogging or running rich issues, no one posts a concrete answer! it all just finishes in a dead end. im just hoping one of these guys has come up witha solution i haven't tried.

[nightwalker]

I don't really know what to tell you. I hate trying to diagnose something on the net. It's so much better to do in person. I'll let you know if I can remember anything.

[Matt_240]

yea, i hate this! how can a problem not have a solution? it just happened out of nowwhere and i can't fix it dammit! im pretty desparate. i think ive pmed or emailed anyone who has had this problem before. the guys who have the exact same problem as me never seem to have an answer though. :wtf:
anyway, there is still hope.. the last things i haven't checked are:
1. 02 sensor on cat
2. change fuel injectors
3. intake gasket

ive changed every single sensor & continuity to ecu, every single ignition component, fuel filter.. maybe theres an unknown vacuum leak somwhere. anyone have a vacuum diagram for an s14?

[nightwalker]

hmm... you could check your cat... see if it's clogged.

[brokenben]

if your cat is clogged up on an obd1, would it still cause idle problems? i thought only obd2 had sensors after the cat.

edit: sorry.. saw that you had an obd2.. but still i just want to make sure thats correct...

my sohc was having similiar problems.. and i went thru and checked a lot of the things on the list.. but now my car is currently not starting.. ive noticed that the cat has been going out for a lil while now.. could that be the source of my troubles?