Help! I also failed smog test HELP

[Marv02]

I tried to pass California smog today it failed The smog technician said it runs lean at Idle but still passes there but a cruise it fails it too rich at 2500 RPM’s.
He said it could be my fuel regulator When I got home I hooked up my pressure gauge reads 40 PSI at Idle 38 PSI at 2500 RPM’s.
Here a copy of the Smog read out Can someone help me figure this out so I can get it pass smog.

 

[Marv02]

Question the car is a automatic the tester had the car in park when he did the testing will this make a diffrence.
I reading other forums the car need to be in gear.

 

[XLR8]

Marv, I can't help with your issue but I'm going to correct the thread title for you. It would be a shame for you to miss out on help (or fail to find it during searches) because of a simple spelling mistake.

Happens to all of us sometime... and luckily it's a fix I CAN help with.

Jane Ann


P.S. - DONE!

 

[tmkassin]

Check your air filter. Make sure there are no restrictions on the air box intake, like leaves or paper or other garbage. Hope it is that simple for you!

 

[boomdriver]

You only missed by a very little....considering all the upgrades to that engine I think you did darn good !

its just slightly rich......
Clean the air filter, if the oil is old change it. Old oil holds hydrocarbon fumes that are released when running and hot.
get the engine to run at 220-230 degrees for the test,. even if that means putting in a hot thermostat. If you are running the test at under 200...thats half the problem.

See if you can get some AV-Gas and blend a couple gal with a couple gal of Ca 91 oct....that should give you a bump to 105-108 area. That will help with the extended burn time of the higher octane fuel. Find a "test-only" and give them the $40 to do a test for tuning purposes....that'll tell you if you are working in the right direction or not. If all else fails, get some painters alcohol and add to 2 gallons of gas. 1 or 2 qts should be enough. Run the test and burn that out asap and refill with good gas again.
I've passed the Ca test (yrs ago) with no cats by running a bunch of alcohol.
Your result is so close that it could have been the fault of the test equipment. Many places do not do the regular maint on the test machines because it cost them time and money.; the machines have filters that get contaminated and if they are not changed they will fail everything that rolls thru the shop door...skateboards, cars bikes & everything with wheels.

 

[Marv02]

The gas tank is full so you thing just run it down to how far then try the AV Gas and aochol trick.

You only missed by a very little....considering all the upgrades to that engine I think you did darn good !

its just slightly rich......
Clean the air filter, if the oil is old change it. Old oil holds hydrocarbon fumes that are released when running and hot.
get the engine to run at 220-230 degrees for the test,. even if that means putting in a hot thermostat. If you are running the test at under 200...thats half the problem.

See if you can get some AV-Gas and blend a couple gal with a couple gal of Ca 91 oct....that should give you a bump to 105-108 area. That will help with the extended burn time of the higher octane fuel. Find a "test-only" and give them the $40 to do a test for tuning purposes....that'll tell you if you are working in the right direction or not. If all else fails, get some painters alcohol and add to 2 gallons of gas. 1 or 2 qts should be enough. Run the test and burn that out asap and refill with good gas again.
I've passed the Ca test (yrs ago) with no cats by running a bunch of alcohol.
Your result is so close that it could have been the fault of the test equipment. Many places do not do the regular maint on the test machines because it cost them time and money.; the machines have filters that get contaminated and if they are not changed they will fail everything that rolls thru the shop door...skateboards, cars bikes & everything with wheels.

 

[Robertwav1]

I failed a while back, took to vette shop and explained the situation. The O2's were working but slow to react with temperature change. The car ran excellent though which really confused me. I guess the tests are getting more and more less forgiving and everything has to be 100%. Had both O2's replaced by the shop (Our emmissions require paperwork) and it went through just fine. Just a thought, had 80K on the sensors and they were getting tired.

 

[Marv02]

All the sensors are new.

I failed a while back, took to vette shop and explained the situation. The O2's were working but slow to react with temperature change. The car ran excellent though which really confused me. I guess the tests are getting more and more less forgiving and everything has to be 100%. Had both O2's replaced by the shop (Our emmissions require paperwork) and it went through just fine. Just a thought, had 80K on the sensors and they were getting tired.

 

[Hib Halverson]

First of all DO NOT go to the smog check with AVGAS in the tank. AVGAS is leaded and will foul your plugs and destroy your catalytic convertor in short order.

Best thing to do fuel wise is a fresh tank for 91 octane gas.

It was suggested earlier to inspect and clean if necessary the air filter.

Have you run the fuel pressure tests in the Service Manual?

I see this car has a lot of mods. What calibration is it using? Does it have a factory or aftermarket cat? If it's aftermarket, what kind is it and is the cat position at the stock location?

 

[Marv02]

It has full lenghts headers but they said there Okay and will test the car with the on yes I have a fresh tank of gas and new oil in the car just changed it the fuel pressure set at 40 at Idel and 38 at 2500 RPM's.

As for the Cat It is a Ca Magna flow 3 way cat it's in the stock postion the air filter is clean and white.

What do you think about the Alcohol trick to help it to pass and removing the aftermarket chip and run it stock I know it wont make the power but it might help it pass smog.

First of all DO NOT go to the smog check with AVGAS in the tank. AVGAS is leaded and will foul your plugs and destroy your catalytic convertor in short order.

Best thing to do fuel wise is a fresh tank for 91 octane gas.

It was suggested earlier to inspect and clean if necessary the air filter.

Have you run the fuel pressure tests in the Service Manual?

I see this car has a lot of mods. What calibration is it using? Does it have a factory or aftermarket cat? If it's aftermarket, what kind is it and is the cat position at the stock location?

 

[boomdriver]

First of all DO NOT go to the smog check with AVGAS in the tank. AVGAS is leaded and will foul your plugs and destroy your catalytic convertor in short order.

Best thing to do fuel wise is a fresh tank for 91 octane gas.

It was suggested earlier to inspect and clean if necessary the air filter.

Have you run the fuel pressure tests in the Service Manual?

I see this car has a lot of mods. What calibration is it using? Does it have a factory or aftermarket cat? If it's aftermarket, what kind is it and is the cat position at the stock location?

You are CORRECT !

My apologies....I was doing that when I had NO CATS....I forgot that marv still has cats.

He CAN get trick gas. Sunoco makes a 106-8 thats for sale in Ca. And it IS unleaded.

 

[Marv02]

There is a place in town that sells race gas I use to run it my bikes back in the day the local place down the streets is now closed so I have to drive 50 miles to get a couple gallons next week.

You are CORRECT !

My apologies....I was doing that when I had NO CATS....I forgot that marv still has cats.

He CAN get trick gas. Sunoco makes a 106-8 thats for sale in Ca. And it IS unleaded.

 

[Hib Halverson]

I'm not sure running racing gasoline is gong to help.

When you say, you have your fuel pressure "set", that implies an adjustable FPR. Why do you have one?

The fuel pressure numbers you quote, were they obtained using the Service Manual method?

Do you have a scan tester? If so, what are the fuel trims at idle and 2500...the "block learn" value is what I'm looking for.

 

[Marv02]

When the motor went together FIC told me to crank up the fuel pressure to 52# to make my 24# injectrs to work as 28# but when I Did this it was pulling to many AMPS so I turned back down to 40# again.

Others have said the higher Octain burns cleaner than 91 Octain pump Gas.

I'm not sure running racing gasoline is gong to help.

When you say, you have your fuel pressure "set", that implies an adjustable FPR. Why do you have one?

The fuel pressure numbers you quote, were they obtained using the Service Manual method?

Do you have a scan tester? If so, what are the fuel trims at idle and 2500...the "block learn" value is what I'm looking for.

 

[Hib Halverson]

When the motor went together FIC told me to crank up the fuel pressure to 52# to make my 24# injectrs to work as 28# but when I Did this it was pulling to many AMPS so I turned back down to 40# again.

"Pulling too many AMPS"? What do you mean by that.
Did you do any testing to verify the fuel pressure increase gained anything?

Remember, for a given fuel pump, a pressure increase always results in a fuel flow capacity decrease.

Others have said the higher Octain burns cleaner than 91 Octain pump Gas.

My guess is, you don't have a gasoline problem, you have a calibration problem. But, you can test that. Run the fuel level low, put in five gallons of 100 unleaded race gas then go for a pre test and see if the anything changes.

 

[Marv02]

I pulled the Chip and tryed to run the car Now I am getting code 44 ad it running to lean I try the Alcohol trick and see if it passes.

How much Alcohol should I use.

 

[KANE]

I see this car has a lot of mods. What calibration is it using?

Hib- I thought the same thing.

Perhaps some time with a dyno and/or a professional tuner getting your PROM tuned to your specific needs with your car would be a good idea. I'm going to go out on a limb here and say that you probably have a custom PROM- but that it may not have had data log sessions used to fine tune it.


While there are a lot of really good tuners out there who can burn a chip based upon what you tell them... it can't replace tuning the actual ECM to the mods/engine work on the car itself. And... if they can hook up a sniffer at the same time, you could tune it to pass the test and get what you want out of the engine performance wise.




FWIW- I had an L82 cam with 1.6 rockers a few years ago in my '80 Vette that drove me nuts with its tune. Took a little while to figure out that while the tune itself was great, the base timing was off just slightly enough (retarded) that the ECM wasn't able to induce knock. Consequently, the ECM failed the self check and the check engine light went on and the car went into limp home mode. It drove me crazy. Once I got it resolved (it needed 2 more degrees of base timing)- everything was great. But I had to data log it to figure it out.

Sometimes when you think something is happening... something entirely different is. My point is when in doubt... data log it so you have a baseline and a history to check in hard copy.

 

[Marv02]

Not saying who or where it passed.

The Alcohol didn't Help.

 

[KANE]

Not saying who or where it passed.

All well's that ends well....

The Alcohol didn't Help.

Perhaps its time for a different alcohol- for celebrating the fact you've passed the smog test.