I'm trying to pass smog and failed on B230F engine at 15mph for NOx.

My other thread [http://www.brickboard.com/RWD/index.htm?id=826087] pretty much went unanswered except for one brave soul who dared suggest I use a near empty tank of gas and substitute drugstore isopropyl alcohol to pass the test.

So the question is: what will this do to my engine?

As Stormin Normin said, why don't you fix the underlying problem? Is this a car that you plan on keeping? Check the 700/900 FAQ in the Features pulldown menu above...there is a list of things that may be the problem for failed NOx, HC and CO. Typically vacuum leaks or a bad cat converter.

In lieu of that, you can retard the timing by a few degrees which will reduce your NOx. This can be done by turning the distributor and setting it once the timing (w/ timing light) is a few degrees less than whatever your spec is (you can find the spec on one of the metal plates in the engine compartment, typically on the driver's side). One caveat, I have heard that California checks the timing on the car to ensure that it hasn't been tampered with. Not sure if this is true or not...

Another option that may be available to you to reduce NOx: This has worked on my 1987 245DL with vacuum ignition advance. Check out my previous post HERE. It lists my before and after data. For the advice on plugging the vacuum line (and confirmation that California checks timing), check out Kane's advice HERE

Good luck with the test, like I said, if you plan on keeping the car, spend the money to tune it up. The investment will possibly be paid off with better gas mileage and peace of mind.

Bean
--
'80 242GT 92k, '94 945T 123k

This is great.

Here's the link to Kane's advice.

It looks like it's down to: a bad O2 sensor; a clogged breather box; a dirty throttle body; or gremlins.

BTW, California DOES check timing so changing timing is not an option to pass smog. But a screw to plug the vacuum hose from the intake manifold to the ignition module might be the trick in the short run.


=:-D

If indeed your car does have the vacuum hose going to the ign module...

Pull off the rubber vacuum connector.
Put screw into the hard plastic hose (I assume yours will be hard plastic also)
Put rubber boot back over screw and connect back to the ignition module.
Emissions tech sees that everything is attached...

Good luck,
Bean

(I'll respond to your other questions at your original post.)
--
'80 242GT 92k, '94 945T 123k

Drugstore isopropyl alcohol can be obtained that is over 90% alcohol. Runs about $2 a quart. YOu may also be able to get gallon quantities from chemical supply at better prices.

Works fine as long as you don't go over about 15% volume...or 1.5 gallon alcohol and 8.5 gallon gas. Essentially an oxidizer.

As to whether it works or not...maybe. If you have a fuel injected car with an 02 sensor, the alcohol will effectively lean out the mixture and the 02 sensor will richen it until the oxygen drops to the proper level. I don't think there is any gain...in fact there is a loss due to excess fuel being burned at higher prices (beside the lower BTU or heat content in the fuel mixture in your tank).

Same goes for the MTBE fuel that is sold in the NE and other areas in the winter for smog reasons...hard to believe or even understand how it works with closed loop fuel injection. I guess it works for carbed cars w/o feedback and it would work at wot when the 02 sensor is cut out.

Reading about Brazil, where they use only alchohol as a fuel, suggests that it will rot rubber and plastic parts and corrode many metals. Besides, I doubt drugstore iso-propal is sufficiently volatale (sp?) to run in an engine. I believe that it is at least 50% water.

Why not just fix the car?

posted by "Stormin Norman"
Why not just fix the car?


Well I'd like to fix this but I need a response to my other posting to help track down the problem.


"Failing Smog on High NOx Emmissions (EGR valve v. Flame Trap or ???)"
[http://www.brickboard.com/RWD/index.htm?id=826087]


I'll try reposting today to see if anyone is in a helping mood on this issue.

The poster from your last message stated:

I used it in the form of gas dryer, but if you read the bottle is is 97% isopropyl alcohol....i ran the tank to nearly empty then put in 3 bottles of the stuff (about 2 drug store size rubbing alcohol bottles).

The gas dryer commonly known as "Dry Gas" is used to help remove water from gas, he didn't use drug store IPA. The three bottles of (any automotive store) bought "Dry Gas" equaled a volume of about two bottles of drug store IPA.

Bean
--
'80 242GT 92k, '94 945T 123k