1sickda

last time i had my car on road it was runnin really rich i was using the stock intake with stock air filter, which most likely was really dirty, could this be a reason my car was runnin rich,, in the muffler you can see and feel the carbon. im just wondering what causes a car to run rich. I now have a cold air intake wit k and n filter just wondering if that will help the problem.

PrincessS2K

When was the last time you changed your spark plugs? Do you have any leaks in your exhaust?

I'm sure the guys can help you out, but I know from watching Trenell and the guys that those two things can lead to your car running rich. I'm not an expert but sometimes when you're O2 sensor isn't working properly, it can contribute to running rich as well.

Good luck Brett!

IntegratedGSR

Contaminated O2 sensors
Loose sensor ground connection
A break or contamination of the wiring and connectors

Carbon Fouling of the Spark Plug

Engine Misfiring

Defective coolant temperature sensor

Defective fuel injectors

If you're getting a rich mixture, it means there is raw fuel and unburned fuel/gases that is not totally burned during combustion.
O2 sensors read the presence of oxygen, so an exhaust leak in the exhaust manifold or anything before the cat could cause the O2 sensor to read a rich mixture.
Corroded O2 wires could cause a faulty rich condition.

1sickda

thanks alot man. as soon as i have it out ill make sure to check all those and if they are damaged or w.e ill fix it.

Buff4Prez Yo

iTrader: (2)

adj. fuel pressure regulator and fuel rail might do it....i know you have those

sikkkkktegra

just advance your timing

esguerra

i hope your not serious...would that fix a possible exhaust leak in the exhaust manifold? would that make the o2 sensors see more fuel in the system so the computer can back off fuel? will that give him the best fuel efficiency?

1sickda

i think my o2 sensor is fucked, reason being last time i got e test the guy told me my 02 sensor is fucked. This was a diagnostic e test place and he tested the 02 sensor so that could be 1 of the problems. Im ordering 1 now ans going to install it when time comes. Also my timing was off large on my car could that cause it to run rich, as well having the odd backfire when downshifting. how can i tell if injectors r fucked?

1sickda

i kno i dont have a exhaust leak because ive had 1 b4 and the car is significantly louder. Last time i drove her sounded fine, no extra noise coming out my exhaust.

IntegratedGSR

Do the O2 sensor. They could be contaminated through time.
If you're talking cam timing, then yes it will effect your air/fuel mixture.
To my knowledge I dont think ignition timing will cause a rich/lean condition. Correct me if I am wrong
You can tell if injectors are bad if they dont hold fuel pressure. If they are bad they will leak/drip.

zman

ignition timing will cause a rich/lean situation....b/c as you advance/retard ignition timing you are burning more/less of the fuel mixture.

IntegratedGSR

^ For some reason that doesn't make sense to me though.
There is still the same air/fuel mixture in the cylinder.
Advancing/Retarding the ignition timing only determines when the air/fuel mixture is ignited. BTDC or after TDC.
Too far advanced Ignition timing may cause engine ping or knock. Starting the car may be slow and jerky, and the engine may overheat if the ignition timing is too far advanced.
Too far retarded may cause a lack in power and performance. Starting may require a longer period of cranking, and it could also overheat if it is too retarded.
I don't see how exactly it would cause a rich condition. The way I see it, you are still burning the air/fuel mixture.
Remember, O2 sensors only can read oxygen, they don't read excessive fuel or lack there of.
A bad O2 sensor will definately cause a rich condition because it is sending faulty information to the computer which will adjust the amount of fuel that is distributed to the cylinders.

"No extra noise coming out of my exhaust" <-- The exhaust leak could be present anywhere from the exhaust manifold to the downstream O2 sensor

esguerra

^^i totally agree....ignition timing basically only controlling when spark occurs...yes it could leave a rich mixture in the cylinders, but a normal operating o2 sensor should pick up on that instantly and adjust for the rich reading...

IntegratedGSR

^

born2board69

iTrader: (1)

lol yea that would be a good reason tothink your o2 sensor isf ucked.

Smartass pHO

You need more tURboZ!!!!

zman

Well, if you've ever tuned a car, you would know that you are COMPLETELY wrong.
I can go outside right now, toss my wideband in my car, hook my laptop up, get the real time programmer going and the datalogging going in CROME and show you, as i advance/retard the timing at idle the AFR (air/fuel ratio) WILL change....thus causing a rich or possibly lean condition.
Would you all like me to take a video of this?
I'm not talking out of my *** here (like LOTS of people do on these forums), i'm talking from DIRECT experience from tuning cars and changing the ignition timing at idle.
Just so you know, if your timing is set to after TDC you shouldn't be working on cars....even at idle the car is running at about 16 degrees BTDC.

Now for a little theory.
As you advance the timing, you are igniting the air/fuel mixture earlier, if too far advanced you'll be fighting against the upward moving piston on its compression stroke and when the whole mixture is completely burned the piston could possibly be still moving up on the compression stroke (which is incredibly hard on the engine) and won't do *** all for making power.
Now if you retard the timing, you are igniting the air/fuel mixture later, if too far retarded the piston will already be past the desired angle to have the complete burn put the most force on the piston and not push the piston down as hard as it should (not make as much power).
There is a specific angle of connecting rod to crankshaft (spoken in terms of degrees) at which the complete burn of the air/fuel mixture will put the most (if not all) of the force of the combustion onto the piston making it move downward in the combustion stroke the fastest (make the most power possible).
Now, the way timing works is that, the ecu has set values (that can be changed in crome/hondata/AEM) for when the spark will fire, this is set to something like 30 degrees BTDC at WOT at 7000rpms (for example). Now just b/c the spark fires at 30 degree BTDC doesn't mean that the air/fuel mixture will be completely burned at 30 degrees BTDC, it takes like 30-50 degrees of crankshaft rotation for the air/fuel mixture to burn completely, or as much as its gunna burn (this will dictate both the air/fuel ratio and how much power the car will make). So, when the mixture is completely burned the crankshaft will be at like 20 degrees after TDC (ATDC) and at that point the force of the combustion will be transferred onto the top of the piston forcing it to move downward, next piston in the firing order to move upwards in the compression stroke faster, thus making the engine accelerate in rpm. Remember what i said before about there being the perfect angle for all of the force of the combustion to be transferred onto the piston, this is the whole point of tuning igntion timing....to get that ignition timing value set to the right degree to where the air/fuel mixture can be burnt to the fullest extent and put the most force onto the piston (make the most power). This is measured on a dyno, hence why its only possible to truely tune timing on the dyno.
So, you want a real life example?
Sure, go to the dyno. Get the AFRs solid, then start tuning the timing and watch what happens.
If you advance timing (generally speaking here) you will usually make more power (provided the engine has it in it). If you advance the timing too far the engine will stop making more power and prolly start to knock (detonate). This is b/c your igniting the air/fuel mixture too soon, and the crankshaft isn't in the right degree of rotation for the force of the combustion to be transferred onto the piston to the fullest of its capability, which will also generally result in a rich condition.
You will also notice, as the car makes more power the AFR will lean out, this is b/c more of the air/fuel mixture is being burned/transferred onto the piston.
Again, this isn't something i'm making up here, its something i've learned while tuning cars on the dyno and from talking to numerous other tuners and engine builers.
So, please, don't tell me that advancing/retarding the timing doesn't effect the air/fuel ratio.
If you don't trust me, i'll take a video of me advancing/retarding the timing real time in crome so you can see for yourself what happens to the AFRs.

IntegratedGSR

^ lol I just said I don't see how. Thats why I wanted you to elaborate.
I never said you were wrong, AND I even stated that.
"To my knowledge I dont think ignition timing will cause a rich/lean condition. Correct me if I am wrong"
So relax.

zman

i'm very relaxed.
Just trying to stop people from ------ing information that is incorrect.
Do you at least understand how ignition timing effects the air/fuel ratio and how it can cause a rich/lean condition?

IntegratedGSR

^ Yea better than before. The information I had was still correct, just wasn't sure about the ignition timing. But I guess that clears things up a little more.

1sickda

thanks alot again z man, im gonna need a tune eventually, um question i drove my car for like 2 months or mayb 3 nothing more. AnyWAYS i used a 1990 stock ls ecu with my b17a1 motor which caused my car to run like total ***. Which resulted in my car to run rich, and one time i was driving and a guy behind me said my car was running really rich he could smell and see the smoke come out. I finally found a vtec ecu and got it wired up, my car then ran really good until i got into my lil accident. i drove for like 2 months not even with the stock ls ecu, then i converted to a jdm sir pr obd 0 ecu and car ran much better. thank alot z man for clearing that up

IntegratedGSR

Ok I talked to two licensed tech's today about this.
Both said, ignition timing will only cause a rich air/fuel mixture if the timing was too far advanced or retarded to cause a misfire. And other than that they said that advancing or retarding the timing slightly wouldn't affect the air/fuel mixture significantly.

zman

So what your saying is that you want me to take a video of me changing the ignition timing real time in crome to prove you wrong and make the two licensed techs (who probably have never tuned a car before) look dumb?

I just re-read your post, and i noticed that you said, changing the ignition timing slightly won't change the AFRs significantly....which i'd have to agree with, but more than just a few degrees (even at idle) will cause the AFRs to change enough (which is what we were originally talking about, how changing the ignition timing changes the AFRs, not slightly changing the ignition timing causing non-significant changes in the AFRs), getting caught up in technicalities here.

Say you've got the car tuned to run 14.7:1 AFR at idle with 16 degrees BTDC. Advance the timing to like 21 degrees (which i would say is more than just slightly) and i guarantee the AFR will lean out. I did this just the other day while tuning a poor mans R with different cams in an attempt to smooth out the idle a little bit, and did notice that the AFR when from about 14.7:1 to around 15.5:1....which on some cars is enough to make the car run a little choppy at idle. I've noticed that on MOST cars they can idle smoothly from anywhere like 12:1 to 16:1 AFR....anything above 16:1 usually results in a n idle thats a little less than desireable.

You don't need to advance the timing soo much to the point where the car starts to misfire, and its doing this b/c the fuel mixture isn't getting burned very well, and the combustion is taking place too early on the pistons way up to TDC on the compression stroke, for the AFRs to lean out.
Pull a bunch of fuel at idle, so the AFRs like 16.5:1, see what happens....the same thing as if you advanced your timing at idle to like 30 degrees BTDC.

Again, i'm not talking out of my *** here.

IntegratedGSR

I'm not saying you're wrong.. but it would be cool to see the amount of differences when advancing/retarding ignition timing.

zman

so, you want me to put all of my equipment in my car to show you what i already explained?

I said in my last post, on the last car i tuned, with a steady idle of 14.7:1 i advanced the timing like 5 degrees and the AFR's leaned out to like 15.5:1. But this was that poor mans type R, every engine is different and will respond differently to certain changes.

I should be tuning another poor mans R this weekend, and prolly dyno tuning a turbo LS this week, i'll take my camera with me, so i can record what happens for you all to see.

IntegratedGSR

^ ya that would be awesome. but hey if you don't want to thats fine.
I'm jus saying it would be cool for everyone to see it. Video's are always good.
I'm not saying you're wrong or anything. I kinda see what you're talking about. My last post was just to tell you what 2 tech's told me.

zman

no worries.
I should remember to take the camera to the dyno with me, besides i'm pretty sure the guy whos car i'm dyno tuning wants to take a video of his car doing some pulls on the dyno, so i'm pretty sure he'll bring his as well.
And yes, videos are always nice....lol.