Need help figuring why I'm running rich.

[Polak420]

Hello everyone,

I have a scanmaster in my car and it tells me that the O2 mil reading is in the 820-850 range with the pedal only a quater of the way down. I have 009 42 1/2 pound injectors, Casper's Electronics Ultra Chip, 160 degree thermostat Front Mnt intercoller, and Poston's Cold air kit. My fuel pressure is 42 at idle. I tried turning down the pressure, but that did not help. I only get about 160 miles on a full tank. This is a street car by the way. Any help would be great. You should see the insane amount of carbon buildup in my pipes from running rich so long. I hope my recently installed headers don't look like that.

Thanks for the help,
polak420.

P.S The CPU settings I drive with are the highest for pump gas. The spark timing is 20 at W.O.T

 

[Quick6'n'-K.C.]

It could be something as simple as a bad 02 sensor?

how old is the one in the car now?
has that 02 sensor seen any leaded fuel possibly causing it to foul out?

BW

 

[charlloots]

did you try turning up the boost a couple of #'s that might help if your o2 is working propaly

 

[gn4u2c]

sounds like to much fuel ..... turn the boost up !!

 

[Polak420]

Thanks for the help every1. My O2 sensor is only a year old so I don't think that's it. I got another question for everyone. How do I set the boost with my adjustable wastegate. I don't have a aftermarket boost guage, and I don't plan on getting one until I get a digital dash from dakota digital. For now I'll just have to do guess work. I'll count the threads on the wastegate, but which way should I turn the screw to increase boost?? Unfortunately it is snowing here so I can't do a road test untill the snow is gone, but I'll still mess with the wastegate if I know how to set it.

Thanks for the help,
polak420

 

[dconnor]

I don't have a aftermarket boost guage, and I don't plan on getting one until I get a digital dash from dakota digital. For now I'll just have to do guess work

That is begging for trouble in the form of a blown headgasket and a good way to quickly join the DOTCC (drove over the crank club)!!! DO NOT mess with the boost settings until you have a good aftermarket guage! Try backing the fuel pressure off a pound or two for now to lean it out a bit & leave that boost at the stock setting.

Have you pulled a spark plug or two to see if the car is actually running rich. Also could very well be the O2 sensor getting lazy, is it an AC Delco?

Checking the O2 readings at anything but WOT & max boost is pretty much useless, unless you're just looking at the idle/cruise cross counts (update rate.) 1/4 throttle & you'll barely be into the
boost at all.

Doug C.

 

[Polak420]

To be honest I don't remember what kind of sensor it is. I got it from Jay's GN. It is the heated O2 sensor kit he sells. One strange thing I did see on the O2 sensor was the Ford logo that was engraved on the sensor. After I shuddered at the thought of this coming from a mustang a I put it in anyway. The kit works fine it is in closed loop. At W.O.T the O2 mil count is in the 920-940 range. Sorry if this sounds dumb but what does taking a plug out have to do with seeing if it runs rich.

polak420

 

[turbowidow]

is fuel pressure gauge accurate? i would verify readings with a new one. are u setting pressure with vacuum line off of regulator? pull the plugs to see what's going on in cylinders- look for soot or lots of black stuff on center wire& core nose (rich condition) you want the plugs to be tan to light brown in color. do you have any BLM or INTEGRATOR #'s? look for vacuum leaks.

 

[Quick6'n'-K.C.]

well since the 02 sensor is heated, they dont give off a code when they fail- the 02 cross counts become lazy and hoover at a certain value and the millivolts dont jump around like they should-

if you pull a spark plug and the electrode is black, its rich,.. but hell you already knew that because of the 02 numbers you gave us, and the tailpipes-

so, sounds like you have no good luck with lowering the fuel pressure, so that points to the 02 sensor just might be bad-

have you ran any race gas in the car?

pull a plug, pull the 02 sensor, both are avail at napa, autozone, advanced, pepboys ect...

HTH
BW

 

[Polak420]

I do have some crappy looking vaccum lines so that might be a possibilty. It is going to snow tomorrow so I won't be able to get the integrator numbers. Does BLM mean Block learn? I've never taken the car to the track. So the fuel I have in it is Mobil Super+ 93 Octane. Hoefully I'll look into the vaccum lines and spark plugs tommorow.

 

[Polak420]

I have a Scanmaster in the car now. I don't know anyone in my town that has a great deal of expierence with GNs. I did hear there is a Percsion Turbo in Hebron which is a good 20-40 miles from here. I probaly am not going to check it out this year if the snow never clears up. The chip should be programmed with the 009s. I bought both the injectors and the chip as part of a package deal from Jay's GN.

 

[turbowidow]

yes, BLM = block learn. search site - razor just had problems with this. looking for values around 118-138 at idle. i had the same problem this summer - car looked like a damn deisel outta the tail pipe( got the stains on the bumper to prove it!) wound up being a combination of bad MAF and numerious vac leaks. does your oil smell like gas? good luck!!!