Alright ladies and gents, I just got back from smog inspection and failed. Passed HC load failed HC IDLE, failed CO Load and passed CO IDLE. It's a '76 Blazer with no cats, no smog pump, 9.8:1 static C/R a 226/228 at .050" camshaft. I know I need to fine tune timing and the carb, the carb is a Speed Demon 650 VS. What are the best steps in tuning these. My CO at load was 6.98 and had to be under 3.00. Any help or wonderful ideas would be greatly appreciated. And yes I know about getting it registered out of maricopa but that's a last resort.
Drewnashty
Drewnashty,
Here in CA there is a product that is called "Guaranteed To Pass". Every time I have used this product the car has passed. I just follow the directions word for word.
The carb needs to be made "leaner" at idle. I think the ignition timing needs to be set with a little less advance while under load. If you have to plug the advance hose so at idle it will check out OK but under a load it will not advance the timing.
But my question is why doesn't it have a catalytic converter?
And lastly you want the truck to be HOT when it is being tested. So take it for a long drive just before you take it in for the test.
On a Jeep with the in-line six I had to run water through the engine to clean the carbon out of the cylinders. It passed but just by a very small amount. I did not want to take the head off to clean up the combustion chambers. The guy doing the testing says that Jeeps build up carbon and then the engine fails because the combustion chambers are too hot and cause the CO to go sky high.
Good Luck
Scholman
Here in CA there is a product that is called "Guaranteed To Pass". Every time I have used this product the car has passed. I just follow the directions word for word.
The carb needs to be made "leaner" at idle. I think the ignition timing needs to be set with a little less advance while under load. If you have to plug the advance hose so at idle it will check out OK but under a load it will not advance the timing.
But my question is why doesn't it have a catalytic converter?
And lastly you want the truck to be HOT when it is being tested. So take it for a long drive just before you take it in for the test.
On a Jeep with the in-line six I had to run water through the engine to clean the carbon out of the cylinders. It passed but just by a very small amount. I did not want to take the head off to clean up the combustion chambers. The guy doing the testing says that Jeeps build up carbon and then the engine fails because the combustion chambers are too hot and cause the CO to go sky high.
Good Luck
Scholman
Drewnashty,
The best thing to do is to find a buddy who works at a shop that will let you take it to him and tune it on their sniffer. This will allow you lean it out enough to pass, and then set it back to where it runs best. Usually leaning out the carb, and increasing the timing will help.
The best thing to do is to find a buddy who works at a shop that will let you take it to him and tune it on their sniffer. This will allow you lean it out enough to pass, and then set it back to where it runs best. Usually leaning out the carb, and increasing the timing will help.
Actually retarding the timing will increase exhaust temp and clean up the end of pipe emmisions. We used to do this all the time with teh old system here in MA. Took cars that were off the chart and set the timing to be retarded and they would pass with flying colors. Just make sure you set it back to normal when you are done.
I would try a 0.015 wire thru the idle jet to lean out the off idle system or Barry Grant also has a press in restriction you could press in to lean out the a/f mixture. the demon carbs have a very active idle circuit mainly because it the carb may be used on anything from a stock motor to a race motor.
Tech @ BG should be able to give you the press in air bleed part #
hope this helps henry @ oles carb
Tech @ BG should be able to give you the press in air bleed part #
hope this helps henry @ oles carb
I had a 1976 CJ5 with the Factory 304v8 and the only way I got mine to pass was to do nothing other than unplug the vacuum advance on the distributor and plug the line and the tip.
Ran like cr@p but always passed with flying colors! Then I'd just pull over on the way home and plug it back together and it ran smooth as silk!
Ran like cr@p but always passed with flying colors! Then I'd just pull over on the way home and plug it back together and it ran smooth as silk!
We had smog tests here in mn. for awhile. Jessie the body through it out. One good thing he did for us.Anyway i had a 86 ford 150 with a 300 six that wouldn't pass. I ran it down to about a 1/8 of a tank of gas or less then i dumped in a gallon of denatured alcohol or paint thinner. It passed in flying colors but i had a hard time burning up the alcohol.
Thank you so much for all the replies. It doesn't have cats because I bought it without them a while back and then I dropped this crate motor in it, and everything fits, so there wasn't a need for change until maybe now. The temp gauge was reading around 190-220 degrees before I took it in.
I am looking into finding a shop or someone to help out first hand.
If I leaned out the carb and retarded the timing would that really be pushing it as far as detonation goes?
The major thing I'm trying to take in account is what will or will not work with my current setup.
Do I not need a special setup for running alcohol? lol, I mean I know the stuff is highly flammable but is it good for the engine internals and carb?
I am looking into finding a shop or someone to help out first hand.
If I leaned out the carb and retarded the timing would that really be pushing it as far as detonation goes?
The major thing I'm trying to take in account is what will or will not work with my current setup.
Do I not need a special setup for running alcohol? lol, I mean I know the stuff is highly flammable but is it good for the engine internals and carb?
Drewnashty,
Well, setting the carb leaner and retarding the timing will not make for a smooth running fast car BUT it will pass the smog test. Then once you have the paperwork turned in and your new tags are on there way to your home, readjust everything back to where it runs the best.
The alcohol is used to clean things up inside the engine for just a short period of time. Just long enough to pass the test. If you ran alcohol all of the time you would need to do more things to the fuel system. Alcohol and "pot" metal do not get along for long periods of time so you only want to use the alcohol to clean things up and then you will go back to regular pump gasoline.
The choke "butterfly" is the front one. The choke ONLY controls that one. It should be standing on it's edge in the vertical position when the test is being run. The secondaries are controlled by the "butterfly" on the rear of the carb. That one needs to be closed when the test is being run.
Even hotter will help pas the test. Now you don't want to keep the hot temps all of the time but during the test you want the engine hot. By taking the long way to the testing center and then letting it sit for a short time will "heat soak" the engine and help in the overall readings of the test. If you just take the car to the test center and it is not hot enough you will get higher than normal leadings from the test because all of the fuel is not being burnt.
You said that you put in a crate motor. Now in CA you would want to take it to a referee to get it verified and then the referee would give the car a tag that goes in the driver-side door jam saying that everything is up to code. Then getting it smogged is not so hard.
Good Luck
Scholman
Well, setting the carb leaner and retarding the timing will not make for a smooth running fast car BUT it will pass the smog test. Then once you have the paperwork turned in and your new tags are on there way to your home, readjust everything back to where it runs the best.
The alcohol is used to clean things up inside the engine for just a short period of time. Just long enough to pass the test. If you ran alcohol all of the time you would need to do more things to the fuel system. Alcohol and "pot" metal do not get along for long periods of time so you only want to use the alcohol to clean things up and then you will go back to regular pump gasoline.
The choke "butterfly" is the front one. The choke ONLY controls that one. It should be standing on it's edge in the vertical position when the test is being run. The secondaries are controlled by the "butterfly" on the rear of the carb. That one needs to be closed when the test is being run.
Even hotter will help pas the test. Now you don't want to keep the hot temps all of the time but during the test you want the engine hot. By taking the long way to the testing center and then letting it sit for a short time will "heat soak" the engine and help in the overall readings of the test. If you just take the car to the test center and it is not hot enough you will get higher than normal leadings from the test because all of the fuel is not being burnt.
You said that you put in a crate motor. Now in CA you would want to take it to a referee to get it verified and then the referee would give the car a tag that goes in the driver-side door jam saying that everything is up to code. Then getting it smogged is not so hard.
Good Luck
Scholman
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