Troubleshooting rich condition?

[99em1]

S50's been running rich fairly recently, and I have some time tomorrow to try to trouble shoot. What are some things to keep in mind/check?

Should I bother to change the oil? It's only been 1500 miles since the last change, but the oil on the stick was pretty drippy.

Also looking to put in oil pressure and A/F gauges soon, and a wideband 02 sensor. recommendations on which ones? installation pointers would be cool too.

[Adrian_Visser]

Drippy? Wtf are you on crack?

[99em1]

What? Rich fuel mixture -> more gas in the engine -> dilutes the oil -> oil loses its viscosity. Drips quickly off the dip stick.

Not sure where you are confused.

[bejbis]

Should I bother to change the oil? It's only been 1500 miles since the last change, but the oil on the stick was pretty drippy.

Ill admit when i read this I couldnt stop laughing.

A faulty air temp sensor, ECU coolant temp, or O2 sensor could cause a rich condition. Most likely the coolant temp, If its reading cold to the ECU all the time, It will remain on its 'cold start' map and keep it rich.

Is the drippy oil your only indication that the car is running rich? Or have you looked in your tail pipe and seen if it is pretty dark in there? ;)

[Adrian_Visser]

To dilute your engine oil you would have to have a completely dead cylinder i.e. the fuel mixture is not igniting at all. Even if the engine is running rich the fuel is still burnt in the cylinder and won't wash out the cylinder and/or dilute your oil.

[gregslow318i]

how rich? have you put a wide band to check afr under load? or Are you just sniffing the tail pipe while its idling on warm up on a cold morning?? is it trowing a code? do you have a cat? something conclusive to indicate a rich condition??

first thing in trouble shooting is to confirm you have problem in the first place, not just assume its something because your oil is drippy....
btw if your oil is diluted by gas it would not necessarily mean your are running rich. could be something like your pcv valve is bad

[e30s52]

What sized injectors do you have and chip?

[99em1]

24lb injectors/JC chip. Rich guess is also due to a poor idle that jumps back and forth from 500rpm to 1000, MPGs have dropped harshly the last couple tanks and the engine feels sluggish. And the oil smells like gas. Someone I was riding with also suggested the idle could be from the computer getting thrown off by having too much fuel. Only code it throws every once in a while is the TPS (1216). I can tell when it's running right because the idle is smooth and the car pulls consistently throughout the curve.

edit: tail pipes are black like any other tail pipe I've seen. nothing out of the ordinary that I can tell.

[matt]

You probably have an air leak after your MAF.

[99em1]

Interesting I'll look into that.

[gregslow318i]

well that and your trowing a tps code....go back and pull the boot of the plug and check to see if nothing is broken, gone bad or is out of range (tps sweep) etc..

[lennon]

24lb injectors/JC chip. Rich guess is also due to a poor idle that jumps back and forth from 500rpm to 1000, MPGs have dropped harshly the last couple tanks and the engine feels sluggish. And the oil smells like gas. Someone I was riding with also suggested the idle could be from the computer getting thrown off by having too much fuel. Only code it throws every once in a while is the TPS (1216). I can tell when it's running right because the idle is smooth and the car pulls consistently throughout the curve.

edit: tail pipes are black like any other tail pipe I've seen. nothing out of the ordinary that I can tell.

like matt said, sounds like air leaks to me.

[99em1]

well that and your trowing a tps code....go back and pull the boot of the plug and check to see if nothing is broken, gone bad or is out of range (tps sweep) etc..

Hmm. Could you elaborate just a bit? I'm not sure how to do a tps sweep etc and I'd like to know if my TPS is actually bad.

Thanks for the suggestions, I'm gonna look for air leaks, and I picked up some MAF cleaner.

[gregslow318i]

Hmm. Could you elaborate just a bit? I'm not sure how to do a tps sweep etc and I'd like to know if my TPS is actually bad.

Thanks for the suggestions, I'm gonna look for air leaks, and I picked up some MAF cleaner.

back probe the plug and check the voltage between the poles (cant remember which ones at the moment) on the sensor as you move the tb open and closed 0v or there abouts mean closed, 5v corresponds to full throttle

this should be done while the ignition is one but the motor is not running (acces position)

[99em1]

*Updates*

1. No intake leaks around the elbow that I could see.
2. Cleaned MAF, runs a good deal smoother and got rid of 75% of lumpy idle when shifting into neutral or pushing clutch in. Still does it sometimes though.
3. Plugs looked great. Not sooty, didn't see any white, just a greyish brown. No oil in the around the coils either.
4. Drivers tail light looks just like the passenger side (no extra exhaust residue etc)

Filled the tank, going to see how far it goes. It seems to randomly do the rough idle and searching out of the blue. When I filled up, it was around 3:30 AM and pretty cold outside (40 ish), and when I started it up to leave, (car was already warm) idle started getting lumpy, and lots of exhaust puffs out the back. Then after 10 seconds or so, idle went to normal 600rpms and couldn't see any exhaust coming out at all.

What do you guys think.