High CO?

confUsed · Post by **confUsed** » Wed Jan 28, 2009 2:03 pm

Hi! I just got the car home from inspection, and I got a feil on too high CO. It was 0,76, and should have been below 0,5 , whatever that means. I dont really know what that means, but the AFR where good (closed loop). The test was taken at 2000 rpm, no load. The weird thing is I had the car tested at that very same machine 3 weeks ago, and I passed. Only thing I have done to the car is changed out the injectors (from presicion 440 12ohm to presicion 580 2ohm and inline resistors) and adjusted the tune to the same afr's. I havent driven the car more than a couple times either. The car has a new cat installed. I had to run a hose from my catch can to the pre turbo intake because of the inspection this time, I think I just had it vented to air the first time, I usually run it that way. When the car is idling, or I'm just keeping a steady 2000 rpms with no load, I can hear it sputters a bit. Like a misfire every second or two, but not enough for the rpm's to drop, so it doesnt really bother me, except it doesnt pass inspection... The plugs have less than 1K miles on them, and air filter is new. Any ideas? I'm thinking just venting the pcv to air in a \"not-so-visible\" way, but I dont know if that really affects CO or not. So any input would be great

Post by **Bugermass** » Wed Jan 28, 2009 3:48 pm

The sputters are more than likely incomplete combustion events.. thats probably why your CO is high. try raising your base fuel pressure up around the 60PSI range retune and try again. This should help you get a finer spray pattern and may improve cumbustion a bit. If this doesn't help then the injectors may just not be opening fast enough at those lower duty cycles and you may be SOL. But try the fuel pressure thing first. its worked for me before, but depending on if the problem is bad spray pattern or just too low duties for the injectors it may also make it worse. Worth a try though. Also check your cap and rotor and make sure the are in good shape. If you can put some iridium plugs in there that would be best, if not .. .. Put some platniums TEMPORARILY but DO NOT BOOST on them.. Just use em for the inspection then pull em out right away.

EITCP · Post by **EITCP** » Wed Jan 28, 2009 4:13 pm

confUsed wrote:Hi! I just got the car home from inspection, and I got a feil on too high CO. It was 0,76, and should have been below 0,5 , whatever that means. I dont really know what that means, but the AFR where good (closed loop). The test was taken at 2000 rpm, no load. The weird thing is I had the car tested at that very same machine 3 weeks ago, and I passed. Only thing I have done to the car is changed out the injectors (from presicion 440 12ohm to presicion 580 2ohm and inline resistors) and adjusted the tune to the same afr's. I havent driven the car more than a couple times either. The car has a new cat installed. I had to run a hose from my catch can to the pre turbo intake because of the inspection this time, I think I just had it vented to air the first time, I usually run it that way. When the car is idling, or I'm just keeping a steady 2000 rpms with no load, I can hear it sputters a bit. Like a misfire every second or two, but not enough for the rpm's to drop, so it doesnt really bother me, except it doesnt pass inspection... The plugs have less than 1K miles on them, and air filter is new. Any ideas? I'm thinking just venting the pcv to air in a "not-so-visible" way, but I dont know if that really affects CO or not. So any input would be great

1. was the cat heated enough? 2. was o2 sensor enabled? 3. did you trying to check if o2 sensor works ok? 4. did you tried to datalog what makes your car misfiring/sputtering? is this ectune related (fuelcut) , bad tuning (too lean AFR) or something else(bad plugs)? PS: all cars i've tuned with ectune passed smog test with excellent score,only those with big cams (buddyclub or skunk2 PRO) didn't.

confUsed · Post by **confUsed** » Wed Jan 28, 2009 4:29 pm

Bugermass wrote:The sputters are more than likely incomplete combustion events.. thats probably why your CO is high. try raising your base fuel pressure up around the 60PSI range retune and try again. This should help you get a finer spray pattern and may improve cumbustion a bit. If this doesn't help then the injectors may just not be opening fast enough at those lower duty cycles and you may be SOL. But try the fuel pressure thing first. its worked for me before, but depending on if the problem is bad spray pattern or just too low duties for the injectors it may also make it worse. Worth a try though. Also check your cap and rotor and make sure the are in good shape. If you can put some iridium plugs in there that would be best, if not .. .. Put some platniums TEMPORARILY but DO NOT BOOST on them.. Just use em for the inspection then pull em out right away.

Thanks for great input! OK, so incomplete combustion raises CO, thats good to know

Also I think its somehow injector related, because I dont think it was sputtering before i switched. I have the oem fpr now, because of what i have read about the b&m unit on these forums

I still have it so I can throw it on tomorrow, tune for 60 psi pressure and see what happens. If that doesnt help with the sputtering, I could put on the stock injectors too, but then I'd have to desolder the resistors again, which sucks :p I really was hoping on getting it done before the weekend, so I'll give it a shot on friday, probably wont get new plugs until then, though, because I'll have to order them. But I took out my plugs and gapped them back to stock, hopefully it'll give a better spark when not in boost, right? I think I changed rotor and cap for less than a year ago, but I'll check them anyway.

confUsed · Post by **confUsed** » Wed Jan 28, 2009 4:35 pm

EITCP wrote:
confUsed wrote:Hi! I just got the car home from inspection, and I got a feil on too high CO. It was 0,76, and should have been below 0,5 , whatever that means. I dont really know what that means, but the AFR where good (closed loop). The test was taken at 2000 rpm, no load. The weird thing is I had the car tested at that very same machine 3 weeks ago, and I passed. Only thing I have done to the car is changed out the injectors (from presicion 440 12ohm to presicion 580 2ohm and inline resistors) and adjusted the tune to the same afr's. I havent driven the car more than a couple times either. The car has a new cat installed. I had to run a hose from my catch can to the pre turbo intake because of the inspection this time, I think I just had it vented to air the first time, I usually run it that way. When the car is idling, or I'm just keeping a steady 2000 rpms with no load, I can hear it sputters a bit. Like a misfire every second or two, but not enough for the rpm's to drop, so it doesnt really bother me, except it doesnt pass inspection... The plugs have less than 1K miles on them, and air filter is new. Any ideas? I'm thinking just venting the pcv to air in a "not-so-visible" way, but I dont know if that really affects CO or not. So any input would be great
1. was the cat heated enough? 2. was o2 sensor enabled? 3. did you trying to check if o2 sensor works ok? 4. did you tried to datalog what makes your car misfiring/sputtering? is this ectune related (fuelcut) , bad tuning (too lean AFR) or something else(bad plugs)? PS: all cars i've tuned with ectune passed smog test with excellent score,only those with big cams (buddyclub or skunk2 PRO) didn't.

1. Yeah, at least he said he had warmed it up :p 2. Yep, wideband in closed loop 3. Last time I checked, 3 weeks ago, the machine read the same afr as my wideband, so at least I hope its still ok. No codes. 4. Couldnt see any fuel cut, and the afr's were hovering around 14,4-15, so I dont think its related to that. Last time it went perfectly fine, only thing thats changed are the new injectors, so I'll try the pressure thingy. Else its back to stock and the 3psi spring in wg for a day :p

greasemonkee · Post by **greasemonkee** » Thu Jan 29, 2009 2:31 am

Seems like a good, hot intake manifold would help with more complete combustion. I know mine doesn't misfire as much when heatsoaked given same afr.

Post by **Gaskleppie** » Thu Jan 29, 2009 2:54 pm

I found a bug in the software last week. In rom .62 and .63 is a problem with closed loop with no load and higher than 2000rpm. It stops working at stand still and higher revs than 2000rpm. Maybe thats your problem. If it is allowed, keep it under 2000rpm and you will be fine.

confUsed · Post by **confUsed** » Thu Jan 29, 2009 3:29 pm

greasemonkee wrote:Seems like a good, hot intake manifold would help with more complete combustion. I know mine doesn't misfire as much when heatsoaked given same afr.

Its -15C outide noe. Kinda hard to build up a nice heatsoak at that temperature

I found a bug in the software last week. In rom .62 and .63 is a problem with closed loop with no load and higher than 2000rpm. It stops working at stand still and higher revs than 2000rpm. Maybe thats your problem. If it is allowed, keep it under 2000rpm and you will be fine.

I just came inside after testing defferent things, and it seemed to me like it was reacting to close loop @2500rpm, I'm not sure, though. I tried setting closed loop to 15, and after a couple seconds it jumped a point and was hovering around 15,5. It was sputtering worse than before, so I didnt leave it there for long. Could have been an coincendent (sorry, dont think I know how to spell that word :p ) Anyway, I checked my cap/rotor, and all four pins inside the cap actually was had a pretty thick layer of corrosion. I cleaned them, gapped my plugs to stock, and found a pretty bad vacuum leak

... I also ran a hose from the top of the catch can down into a not so visible place behind the motor, so I'm not burning the oil mist. The sputtering is almost gone now, and the afr is more stable (still hovering a bit, but I guess its not possible to keep it completely stable? I have never been able to do it). So I'll give it a try tomorrow, hoping for the best

Post by **calvin** » Thu Jan 29, 2009 7:40 pm

being fixed

confUsed · Post by **confUsed** » Sat Jan 31, 2009 7:48 am

Just to update, I passed the test. At idle the values were perfect, but at 2000 rpm CO was way high even though all the other values were good (AFR was spot on). But the guy was cool and printed the results at idle, so no worries for two more years :p I'll probably do a quick retune with stock injectors (and run a weak wg spring) next time.

HiProfile · Post by **HiProfile** » Mon Feb 02, 2009 2:24 am

High CO is usually consistent with AFR's below stoimetric, 14.7:1. It probably has to do with fuel 'fighting' for oxygen, and each carbon atom getting 1 less oxygen atom. Regardless, that's what chat that plots rough PPM values for all the major pollutants in a gas motor based on AFR. Popping could be a misfire as stated before. A misfire can deceive the O2 sensor, since it only 'sees' oxygen, not unburnt fuel. The misxture would be slightly lean to the sensor, but rich in reality. This is why its very important to avoid misfires while datalogging. Another issue Gaskleppie brought up could be the load they put on the car. The place I used to go to (before I circumvented the system) did a simulated test with a loaded roller, and placed an decent load on the motor. I was only failing the visual test, since my open-element filter was somehow 'leaking gases back into the air'...old d-bag working there must have hated imports.

eCtune

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