How do you know if your running rich??

[charleslong]

How do you know if your running rich??
what would you do if you were running rich? also how do you know if you are running lean, and what would you do?

 

[MeanBuicks]

Running rich can cause black smoke, slow spool, high O2 sensor numbers and low block learn numbers.

Opposite is true for lean conditions with the added danger of knock. A scan tool is a must to determine for sure what your situation is.

These problems are corrected by either fuel pressure adjustments or, for more extreme requirements, by changing fuel system components; ie. pump, injectors, chip.

 

[motorhead]

Originally posted by charleslong
How do you know if your running rich??

...Follow your nose!

what would you do if you were running rich?

...Add more boost?!

Get a scan tool... they ROCK!

 

[49-blues]

wouldnt higher o2 readings indicate lean-being theres more air content and less fuel content? and lower o2 readings mean running richer?

 

[Gn-Krazzie]

Isn't popping and indication of running lean ???

 

[BLACK6PACK]

49 blues,
you have it backwards. Low 02 counts mean it is running lean, but low INT & BLM #s mean that it is rich and trying to pull fuel out of the mixture.

 

[ncgreg231]

Originally posted by charleslong
How do you know if your running rich??
what would you do if you were running rich? also how do you know if you are running lean, and what would you do?

Unless you are pumping big clouds of black smoke out of the exhaust pipes (running rich) or denonating so much that you can hear it by ear, you really need a scan tool of some kind to check for this. If you run rich for too long, you can cause the catalytic converter(if you have one on your car) to melt itself into a solid lump (and your car won't run) As well as "washing" the cylinder walls of oil film protection.

The scan tool will show you what your O2 sensor is seeing. Another parameter to look for (if available) is the O2CC (oxygen cross counts) this parameter describes how many times a second the 02 sensor crosses the "stochiometric" (theorectially perfect) fuel-air mixture. With a stock chip, at idle, O2 volts should jump back and forth between mildly rich and lean, with a 02CC reading of about 25-35 (I think) Some chips (like Thrashers, at least) are reprogrammed to run lean all the time, so 02 data may be different. If 02 data is consistently high or low, if 02CC data is low, if BLM and INT data is way off, the first thing you might want to do is change the 02 sensor, and see if the data changes after that. If you have an adf f/p reg, try playing with that and see if that changes anything. The next thing I would do is something to clean the injectors - atomization problems can do funny things.

How modified is the car? Mismatched injectors, misadjusted f/p, weak pump (=lean condition) can all be problems...

HTH

 

[MikeH]

I am running into high O2 readings and still getting a whole bunch of knock. I know that high O2s mean a rich condition, but I didn't think I would get the knock I am getting. The other thing that is throwing me off is, my BLM readings are in the high 140s to low 150s, which should mean a lean condition, right? How can I have high O2s, and high BLMs at the same time?

 

[UNGN]

Originally posted by MikeH
I am running into high O2 readings and still getting a whole bunch of knock. I know that high O2s mean a rich condition, but I didn't think I would get the knock I am getting. The other thing that is throwing me off is, my BLM readings are in the high 140s to low 150s, which should mean a lean condition, right? How can I have high O2s, and high BLMs at the same time?

Knocks primary cause is a lack of octane and secondary cause is a lack of fuel. You can have LOTS of low octane fuel and still get knock.

I trust O2 readings as far as I can throw an O2 sensor. Add octane and see if the knock goes away. That should eliminate at least one variable.

 

[MikeH]

Thanks for the reply UNGN. For some reason I keep thinking it shouldn't knock if it is getting fuel and forgetting that it all depends on the octane. I am running 93 with a RA93 chip, but the gas around here is garbage. Would it be safe to say that I might have a bad O2 sensor since I am getting high readings on that and also high BLM readings? They should be opposite each other shouldn't they?

 

[ncgreg231]

How much boost are you running? What's your setup? what kind of turbo, injectors, f/p reg? what f/p setting?

IMHO, it's more important to run with zero knock than anything else. (unless you have deep pockets and like to spend $$$) I never played around with the BLM & INT numbers too much, but at WOT, you shouldn't really be worrying what those numbers are (again, JMHO)

as with any issue, there could be other stuff contributing (poor atomization = rich mix, but poor mix) maybe one sticky injector that causes the computer to be leaning out all the rest?

Hmmm

 

[ncgreg231]

BTW

high oil contamination (if turbo seals fail/leak) can reduce actual octane. (I think) So maybe check intercooler/hoses/up-pipe for signs of oil? This can also come from the passenger side valve cover breather tube, if it is still hooked up...

 

[MikeH]

Boost is set at about 16psi, stock injectors, Walbro pump(hot wired), fp set at 43 line off, and stock turbo.

 

[ncgreg231]

still knocking?

I looked back over this thread. You never really mentioned it, but you are talking about knock only at WOT, right? All other drivability okay?

An easy check (if you haven't done it already) is check the turbocharger compressor discharge (the pipe that goes from the turbo to the intercooler) for any oil collection. An easier place to check is the intercooler up-pipe (between intercooler and TB) but I've noticed a little oil in mine that is making it's way back from the PCV/TB area. Hopefully somone will correct me if I'm wrong, but I want to say oil contamination will act to reduce the "effective" octane of the fuel/air mixture.

Did you mention that you had gotten rid of the passenger side breather tube (connects to turbo inlet bell)?

What kind of gauge are you measuring boost with?

At this point - you might be simply running too much boost for the octane you have. And maybe (and maybe not) you have a little oil contamination adding to your troubles? You might consider replacing the 02 sensor, but I don't really recommend it. Especially if you have high 02CC and only a little mV variation during part-throttle cruise - because this means it's working fine. Unless you get a "wide-band" sensor, the stock 02 sensor (I'm told) is not accurate anyplace but at "perfect mixture" At WOT, the sensor should read "rich" Seems like RA93 chips were supposed to "lock-up" the BLMs during WOT (the new ones anyway, call Quad air to check this) so not sure what to make of BLMs that aren't at 125.

For optimum FP setting, make 1/4mile pass (I guess a "G-tech run" would be okay) and check MPH. Raise FP @ 3psi, repeat test until car "slows down" in MPH.

Oh yeah, exactly how much (how many degrees of) knock are you getting?

 

[charleslong]

I think my car is running lean instead of rich, b/c when i go wot from a stop, it will pop. As if the fuel had been shut off or something. How would i richin the car up if it is running lean.

 

[BLACK6PACK]

Turn up the fuel pressure or turn down the boost.

 

[charleslong]

thanks guys,
where would the fuel pressure adjustment be?
also would my car run better if the boost was down?
I just bought a thrasher chip

 

[Boston GN]

Well what you need to do first, instead of taking stabs in the dark, is get yourself a scan tool. Scanmaster at the very least. The from there you can see your O2 counts and BLMs. Get a fuel pressure gauge and see where the fp is at. The adjustment would be on top of your adjustable fuel pressure regulator, if you have one, right on the fuel rail. Like you said: you "think" you may be lean. Well, thinking isn't good enough with these cars, you need to know!!!! Otherwise you could be picking up pieces of your motor soon.

 

[ncgreg231]

Originally posted by charleslong
thanks guys,
also would my car run better if the boost was down?
I just bought a thrasher chip

The car might be a little slower with less boost, but with zero knock, the engine will LIVE much much longer. For the thrasher chip, do you know if you have the "lean cruise" option? Just like it says, the computer will run the engine lean during cruise, not to conserve fuel (although this is a side benefit) but to have the exhaust a little hot so the turbo will spool up quicker. On my car, this will give me a little bit of knock when I go from cruise to WOT. I generally try to tune for ZERO knock.

You don't "need" to turn the boost down, you "need" to run with zero knock. You can be limited by octane, an inadequate fuel supply, the list can go on and on. Having a fuel pressure gauge that you can see when you are driving at WOT is just as important (more important IMHO) as a scan tool, because even if you have an adjustable fuel pressure regulator (the cars came with non-adjustable f/p regs) and a gauge on the rail, if you have a condition where f/p drops off during WOT, you aren't going to know without a gauge you can see at WOT. If you only have the scan tool, you might be running lean, with big enough injectors, etc, but that one crucial piece of info is missing from your analysis.

BTW, either have the gauge attached to the hood/cowl/windshield somehow, or get some kind of "isolator" b/c it would be unsafe to have a regular set up with the gauge inside the car (like the way a mechanical oil pressure gauge is set up)

HTH

 

[charleslong]

thanks guys, about the scan tool deal, i have direct scan but it is on my laptop. the laptop is old and the keyboard stop working so i cant adjust the brightness enough to see it.
I put the other chip back in, and while unhooking the orange wire under the hood, i noticed that it was stuck to my turbo exhaust. (burned). But i fixed that problem, and put the ultrachip back in and it does not pop any more. I think that problem is fixed.