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Emissions failure? PASSED!@!!!!!!! WOOT


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After reading OB99W's post, another thought came to mind. It may be good to check and see if the coolant temperature sensor for the ECU is working as it should. This may be causing the mixture to run rich if it doesn't see the temperature go up as the engine warms but also wouldn't throw a error code if the circuit looks ok to the ECU.

Yes, a bad ECU coolant temp sensor can do that. So can a stuck open thermostat (not common), or a missing one (someone may have pulled it); might not be obvious until the weather gets colder.

 

High HC could be due to a burned or otherwise leaking exhaust valve; a compression test should reveal that.

 

By the way, is this car a 2WD? I'm asking because cruise emissions were quoted, which is a dyno test, and few test stations have 4-wheel dynos.

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Yes, a bad ECU coolant temp sensor can do that. So can a stuck open thermostat (not common), or a missing one (someone may have pulled it); might not be obvious until the weather gets colder.

 

High HC could be due to a burned or otherwise leaking exhaust valve; a compression test should reveal that.

 

By the way, is this car a 2WD? I'm asking because cruise emissions were quoted, which is a dyno test, and few test stations have 4-wheel dynos.

 

another possability at this mileage is a leaking fuel injector or two.

 

Check the simple stuff first.

 

nipper

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another possability at this mileage is a leaking fuel injector or two.
Yes, if things are really rich, both the HC and CO would be high. It could even help explain why the idle numbers look worse than at cruise. Of course, if the cat saw much of that for long enough, it's probably not doing its job any more, compounding the problem.

 

 

Check the simple stuff first.
Amen.:)
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Yes, if things are really rich, both the HC and CO would be high. It could even help explain why the idle numbers look worse than at cruise. Of course, if the cat saw much of that for long enough, it's probably not doing its job any more, compounding the problem.

 

 

Amen.:)

 

can the original poster do something to humor me? Bang on the cat with your hand and see if it rattles. If it rattles, it is dead.

 

nipper

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Isn't the default condition for a bad MAF to run rich? Would that also meet the other indications from his test?

 

there is a long list of what it could be. Since the car has high mileage and unknown history, we need to start off with the cheap things first, and do only one at a time. Since this is an emissions test, he can't really test it in his driveway.

i would do all the cheap things first (checking sensors, cleaning, insepcting. replacing inexpensive parts).

Fuel injecters, if they are leaking, can be had a scrap yard. Do an opil change, check to make sure the car reaches operating temperiture (thermostat) check the temp sensor for the computer. Borrow a code reader and see what the sensors are doing. Inspect the spark plugs, check the gaps, clean and regap if on a low budget.

PCV and air filter of course.

Thats the down side to this, mechanically you fail an inspection you fix it and see the results. Emissions you cant see the result without going back to an inspection station. You do what you can in layers, but only one at a time, incase you do something to make the car run worse.

 

nipper

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No noise from the cat,

 

I have to replace the main pulley so I'm gonna take a look at the timing belt, and see if its off a tooth,

 

Also my brother who is a mechanic for Killed In Action (kia), said he has this miracle additive that you add to the gas, the oil and you pump it through the intake, so We are going to attempt that also...

 

z

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No noise from the cat,

 

I have to replace the main pulley so I'm gonna take a look at the timing belt, and see if its off a tooth,

 

Also my brother who is a mechanic for Killed In Action (kia), said he has this miracle additive that you add to the gas, the oil and you pump it through the intake, so We are going to attempt that also...

 

z

 

Scary Terms ..

 

"hey watch this"

"this wont hurt at all"

I have this miracle additive"

:rolleyes:

nipper

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Took it to work today because my '81 left me stranded, started throwing a code check engine, so I decided to pull the codes and connected the black connector got a 32 on a new Oxygen sensor, so I figure I got it hooked up wrong, its a bosch splice your self, the old sensor has three wires red white and black, and my new one has black white white?

 

Any ideas??

 

or should I just splice my nasty looking old one in?

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Took it to work today because my '81 left me stranded, started throwing a code check engine, so I decided to pull the codes and connected the black connector got a 32 on a new Oxygen sensor, so I figure I got it hooked up wrong, its a bosch splice your self, the old sensor has three wires red white and black, and my new one has black white white?

 

Any ideas??

 

or should I just splice my nasty looking old one in?

The 3-wire sensors usually have an output/signal wire and 2 more for the heater, with the ground connection made via the shell. Bosch O2 sensors typically have the two heater wires the same color (white), since the heater has no polarity and it doesn't matter which is which. The black would then be the output/signal.

 

How did you match the colors?

 

As has been suggested earlier, going OEM for the O2 sensor is a good idea because OEM is more likely to be an exact match for the ECU requirements. That doesn't mean that the Bosch unit is the culprit, though.

 

An O2 sensor whose output doesn't oscillate isn't necessarily faulty. For example, if the engine is running very rich, the O2 sensor output will be used by the ECU to try to lean the mixture, but if the rich condition is due to sufficiently leaky injectors, the ECU can't correct enough, and the O2 sensor can't swing the other way.

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Ok, cleaned the Maf, Used Lucas Fuel injector cleaner and sprayed a bunch of carb cleaner in throught the brake booster line, And Pulled the old air filter out. I've been driving it to work and back because the carb went out on the Purple people eater... it seems to be running great and the only time I get a check engin light is after I try the cruise control...

 

It now Idles (barely) with a vacuum hose unhooked.. friday I'm going to try some Seafoam in the Gas and the Vacuum lines and change the oil.. and take it back down Emissions because it isn't spitting out a bunch of Brown/Black exhaust... I think part of it was the Maf or one of the other sensors was clogged so there for it set the timing to low Which would explain idleing at 500rpm and when I took a vacuum line off it would immediatly die...

 

but now it runs smoother and boy does she get up and go..

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