smog sigh...

[Jin-Chuu]

I recently smogged my car and here are the results.

1st time:
15 mph: %CO2 11.9 %O2 0.1 HC 274 CO 4.52 NO 395
25 mph: %CO2 12.0 %O2 0.1 HC 265 CO 4.39 NO 268

Alright after the first time I pulled my engine replaced my headgasket, EGR valve gaskets, Intake gaskets, Helicolied my exhaust studs, etc etc basically replaced a whole bunch of gaskets and whatnot. My vacuum before would be erratic 10-15 now its a steady 20 at idle. I also replaced my o2 sensor and a cat that I used to pass smog before.

2nd time:
15 mph: %CO2 13.2 %O2 0.0 HC 161 CO 2.77 NO 161
25 mph: %CO2 12.9 %O2 0.0 HC 173 CO 3.23 NO 129

I replaced the o2 sensor with a bosch single wire. So the two heater wires are unplugged right now. Also my BVSV or that green thing has broken off. My charcoal canister is also removed. My timing is dead on 10 with the jumper in and 12 without. Idle is dead on 650. Running great except for it feels like theres no power. Also there are no codes flashing.

I'm swapped the stock dp on and the stock exhaust except for the tip.

I'm officially lost.

 

[jetjock]

I'm surprised you passed at all with the evap system removed. They should have gotten you on the visual alone. The exhaust stream in both cases is rich, obscenely rich in the first case. Assuming the cat is working it must be even worse engine out. The engine is obviously not in fuel control. You need to confirm it by measuring for O2 sensor cross counting and average voltage on Vf with T and E jumped and the throttle off idle. 2500 rpm will do. Check the coolant sensor too. If all that's Greek to you it's time to take the car to someone who understands it.

 

[supraguy@aol]

Wondering if you checked for any codes, as we always ask. I wonder if you're getting a KS error.

 

[Jin-Chuu]

Yes I've checked the codes and attempted to check the o2 sensor using the terminals jumped. It seemed fine to me.

 

[bryanintexas]

I'm surprised you passed at all with the evap system removed. They should have gotten you on the visual alone. The exhaust stream in both cases is rich, obscenely rich in the first case. Assuming the cat is working it must be even worse engine out. The engine is obviously not in fuel control. You need to confirm it by measuring for O2 sensor cross counting and average voltage on Vf with T and E jumped and the throttle off idle. 2500 rpm will do. Check the coolant sensor too. If all that's Greek to you it's time to take the car to someone who understands it.

Not to thread-jack, JJ are you refering to the EFI temp sensor? I recently failed as well. EGR was clogged, but while doing the EGR, I looked over some things and noticed my EFI temp sensor was broken (top half pulled off w/ the connector) I have replaced it, but was wondering if that helped to contribute to the failure. Sorry, I have no result #'s (it was being tested as a favor no pass=no pay) I was told however it was a lean condition.

B

 

[jetjock]

I am indeed referring to that. Since he's rich there's a possibility the engine is remaining in warm up enrichment. As with most EFI systems in this car the coolant sensor has higher authority than the O2 sensor. He may or may not get a code for it. If it was shifted but still within limits he would not. In your case (in theory at least) it should have set a code 22 and defaulted to hot. Unlikely to be the sole contributer to an emissions failure since the engine normally runs at the default temperature. All that said his problem could be anything that keeps the system out of fuel control. The one wire O2 sensor wasn't the smartest idea but it shouldn't be the cause.

 

[Jin-Chuu]

Ah are you talking about the ecu temp sensor? I was wondering about it since on cold startups my car doesn't idle at 1500 or so. I've replaced the sensor and checked the wiring but on startups it would start at 1000 then after a few seconds go down to 650.

 

[Jin-Chuu]

Alrighty so I narrowed it down to the O2 sensor. Testing with the jumpers set at idle and 2500, it doesn't fluctuate 8 times as the tsrm says. It doesn't fluctuate at all, I traced the ox wire from the sensor to the ECU and it still has continuity. Should I swap ECUs as the tsrm says to do?

 

[Jin-Chuu]

I'm measuring from the Vf terminal. It's stuck at 4.94 at idle with T and E1 shorted. At 2500 rpm it is at .02. I'm using a multimeter to do these measurements.

Thanks for taking the time to help.

 

[jetjock]

You need to determine if the sensor has failed or it's reporting a legitimate condition. Two ways to do it: On the car or off the car.

On the car: If it's stuck rich ( it is in your case) make the engine lean. Pull the brake booster line off or introduce a largish vacuum leak some other way. If it wants to stall up the rpm to keep the engine running. Watch for the signal to rapidly switch to 0 volts. To check if it responds to richness make the engine rich. Inject propane from an unlit torch into the brake booster nipple on the intake manifold or give it a shot of carb cleaner. Watch for the signal to rapidly change to 5 volts. If the sensor responds to you manipulating the mixture the sensor is good.

Off the car: Remove the sensor and connect your voltmeter to the one wire and sensor body. Set the meter to measure millivolts. Using a lit propane torch heat the sensor tip. Get it good and hot (near red) but don't melt anything. The meter should read at least 800 millivolts at this point. Remove the flame and the meter should quickly go to less than 200 millivolts.

Play the flame back and forth across the sensor tip and see if the voltage rapidly swings from high to low. Finally, keep the tip heated as much as needed to keep the voltage high for a few minutes while watching to see if it stays steady and doesn't break down. If the sensor passes either of these on or off the car tests it's good and the richness is being caused by something else in the system ie; another sensor, high fuel pressure, ect.

What concerns me is Vf is showing lean while your exhaust is rich. That means the system is in open loop. I'd be measuring the O2 sensor directly in this case.

 

[Jin-Chuu]

Okay so I did the in car test. I pulled the brake booster line and it jumped down to .02 but thats with me pushing the throttle a little bit. I see that if I just push the throttle a little the reading would drop to .02 even if i didn't pull the line. I sprayed carb cleaner through the line and had no response from the readings. So I suppose the sensor is bad?