Rich Idle

**kbentzel** · 01-03-2009, 05:25 AM

I have a 02 LS1 from a vette. It's running very rich at idle. I mean black smoke eye burning plug fouling rich. No codes, IAT, MAF, MAP readings seem fine. The car runs but is not road worthy so I don't know what would happen at speed. The fuel reading never goes closed but I have seen it at open2? The advance at idle is all over too 3, 10, 34 and the O2 voltages seem to stay in the .450 range. Any ideas would be appreiciated.

**0rion** · 01-03-2009, 07:55 AM

are the O2's staying at 450mv? Is there anything else you can tell us about the car? Was it running fine then just started this? Is it a swap motor? Any other info you can give will help. I'd hate to say "bad O2's" which is usually a sign of them staying at 450mv but if you're that rich something else could be causing it such as a temp sensor and it's fouled the O2's. Please give as much detailed info as you can.

**kbentzel** · 01-03-2009, 08:35 AM

The vette was totaled. I bought it as a donor for a FFR GTM build. It ran when I got it. It didn't idle well then either. The PCM was replaced and reflashed, I replaced the O2 sensors. I'm just using the ones up stream of the cats. Shouldn't the Fuel system go closed after the engine warms up? I don't think it even looks at the O2 sensors until it goes into a closed mode. I never see this. It goes from open to open2 with a coolant temp of 180. Is it normal to see the advance jumping around so much? At idle the MAF was reading about 3.7 g/s. I don't remember what the MAP was reading. The IAT was correct at 77 deg?

**0rion** · 01-03-2009, 02:18 PM

I'll have to think on it for a bit......the car isn't entering closed loop so the O2's are a non-factor. What are you using to scan it with? The 180 temp, is that a scanner temp from the sensor itself or is that a gauge temp?

**kbentzel** · 01-03-2009, 06:05 PM

It's an Actron scanner and that's where the coolant temp reading is coming from.

**BowTied** · 01-03-2009, 06:25 PM

The non-technicals:

What about the gas?

You say it isn't streetable...makes me think it might have got some gas from a can (or perhaps burning old gas from the tank...doubtful source). Because I'd think from your description it is oil burn, that would have to be powerful rich otherwise!

I have seen people put some gas in their car that was for a 2-stroke engine they had, lawn mower, weed eater, dirt bike!

Either way I'd check that gas...have you really stoked somebody lately...do you have punk kids in the neighborhood?

Next check your dip stick! I might be way off but I'd be making sure you are not burning oil!

Is their a slightly blue hue to the exhaust?

**kbentzel** · 01-04-2009, 03:33 AM

The LS1's not two stroke? Kidding. The gas is new. It's definitely fuel not oil.

**BowTied** · 01-04-2009, 07:04 AM

Haaah! You know it is a 3 stroke methane-diesel!

Then...
1 - Not getting into closed loop operation!
2 - Closed loop fueling is whacked!

Well - probably a 3rd....NO CODE

I always look for 1 answer for problems. But on a swap that goes out the window. It sounds like it could be running uncontrolled and the program is suspect. I'd want to run it for an hour or so (sucks I know) with all 4 O2's installed. Because I'd really want to know if the PCM won't throw a code.

**BowTied** · 01-04-2009, 07:05 AM

Wait a minute, you said the donor is a 01 Vetter...what is the recipient vehicle?
What about the engine harness, where is it from? Has the harness been worked on?

**kbentzel** · 01-04-2009, 10:19 AM

02 vette. The engine harness is from the vette. You are right it's not going into closed loop. That's what is puzzling me. It goes from open to open2. I have never seen it go closed.

**BowTied** · 01-04-2009, 10:43 AM

I am not a guy to over react, but I'd get through about 1 night with that thing not throwing a code.

I do things different from most guys. I have a ProScan 5.0 and after those basic readings I use all my electrical equipment. I can patch in and manipulate sensor values going to the computer and quickly verify their operation and the computer/system response. Without the electronic equipment I'd really be Jonesing to find a way to run it long enough to get me a code.