I'm needing some advice on my 85' LG4.
The thing just won't pass this year and I'm getting frustrated with it.

My 1st tests results:
So after the miserable failure, I bought a new timing light because I knew my timing was heavily advanced to make the thing go a little better. Did a few things, set the timing so the mark was "straight up" on the balancer since my motor does not have a timing indicator, bunch of parts like new oil, new plugs, new air filter, new pcv, new breather filter pad and put in some 93 octane. Rotor and cap have less than 1K miles on them so I figured I was ok on them.

Went back Saturday morning and got the following readings

So figuring a little less timing helped I reduce it some more and tried again today.

I believe I'm at the point where timing is not going to help (still don't know exactly where its at without an indicator)
I think I've retarded it at least 20 degrees from where I started.
The car has absolutly no power and accellerating even kind of quick it wants to die. Getting on it slowly works ok but takes a long... long time to get up to speed.
O2 sensor is crossing ok and seems to be working decently.

Is a new cat the only option left?
Really didn't want to put one on.

Need to get it passed to get my collector plates on my good car (the one that does pass emmissions) so the HSR, headers and 3" can go on.
TIA,
John

 

Put one on meaning you don't have a cat? That would DEFINITELY be the problem. If your state has emissions- almost all cars won't pass without a cat.

 

Has one but is probably the original.
Did a cat back exhaust last summer but am holding off replacing the cat cause I only wanted to keep the car till next spring.
The last time (two years ago) the numbers were good. I fiddled with the carb a bit and now have the one from my 86' monte SS on it. Might be a little on the rich side but it runs much better than the old one but the timing needs to be alot higher to run well.

 

You're definitely running rich, just look at your CO #. I'd try to tune your carb a little more. A new cat would probably help, but costs $$$. Tuning carb = free! Lean it out, even if it runs like crap and has no power, just long enough to pass emissions, then set things back to where it runs better

 

Doesn't high CO numbers indicate a lack of oxygen? Meaning it's rich like said above, and/or you had and removed the AIR stuff....

 

everything but the EFE valve on the exhaust is there and working.
I went and had a cat put on today and installed a new O2 sensor.
Guess what?
It got worse !!!!!!
I may have went too far retarding the timing because everything went back up again. I'll post the numbers shortly.
To make it worse, I can get an exemption if I made an improvement of greater than 30% and spent $200 on parts.
I nailed it at $ 191.55 (couldn't find another recipt)
Should have bought the expensive cap and rotor
POS LG4!

 

Damn im glad theirs no emissions laws up here

 

high HC is running rich, hi CO your a little lean. HC = hydrocarbons. Retarding your timg will lower HC, CO some, and help NOX. If you cat is clogged, it'll give you high CO( and HC). Do you have an enhanced emissions program?? I.E., run on a loaded dyno @ 15 mph? You may want to try readjusting the idle mixture screws. clean/change you PCV valve and changing the oil. When a car comes into my shop and fails like that, carbed car, I usually have to do said things, timing, idle mixture, pcv, oil change.

In case your wondering, the engine draws all the blowblow from the PCV valve and reburns it. So if the oil has gas/contaminants in it, it'll raise your emissions some. Too bad you ain't in PA, I'd get it to go through.

 

I've pretty much replaced it all at this point.
PCV, all filters, oil, plugs, cap, rotor, fuel 93, CAT and O2 today.
The carb is the only thing I havn't concentrated on because its been running real nice with the one from my 86 SS on it. The original didn't work real well after a few times rebuilding it. Need that $%^ tool to adjust the MCS while it runs, I think that is my whole problem.
Or I could just put a TPI on it and it would pass easily
Not having a timing indicator on this car is driving me nuts. Stock says put at TDC "0". If I estimate aprox where that would be regarding every other SBC I've dealt with I'm advanced about 20 degrees from my estimation. I got the best results when the mark on the balancer was about at 12:00 position (with the dizzy unplugged). To me TDC should be about 1:00 IIRC.
That was where it was at on the 3rd attempt. It seemed there was a little more retard to be had without running worse so I moved it there and the results were worse than previous.
I'll probably just go buy a ignition module for my Monte and take the exemption for the year, turn the timing back up to where it ran nice and sell the thing in the spring.
Nice car, just had enough with the little problems on it.

 

Replace your O2 sensor.

High HC can ruin a cat, yours may be toast. Put on a replacement Magnaflow cat.

take it in for a test after driving it around for about a half hour to make sure the engine and cat are HOT.

 

He said he just replaced the O2 sensor.

High CO is a rich mixture. High HC is unburnt fuel and indicates a miss. A rich mixture tends to cool down the combustion temp, which will knock down NOx, which are low in this case. Sure looks like a rich mixture.

Of course, at what RPMs this is happening isn't mentioned. They give you a graph of emissions vs. speed when you fail here. You may have the classic "well plug" leakage problem, or MCS that isn't working properly. Or, float level set too high.

Dumb question: Are you setting the timing with the flat 4-wire distributor connector disconnected?

 

The O2 AND a new cat.
The 4 wire is disconnected, that's what is really bugging me about the position of the timing mark.
Its up at 12:00 to get the best emmisions. I've never seen a SBC that had the mark that far up.
Romped it on the highway for 20 miles in second gear to be sure it was blown out and hot
Then drove right in for the test. It is a rolling 25 MPH test.
I'm not sure of the rpm at that point but an estimating 1800-2000.
I'm almost certain the well plugs could be leaking AND the MCS is not set right. I'm sure this carb is running rich and it makes sense in the fact that it really loves the added timing.
I've epoxyed every carb I've installed except this one. Something else I should have done.
I just picked up a real nice book with full setup procedures for the carb so when I get back in a week (out of the country for work) I can start again and make sure everything is right.
By then all of my cars plates will have expired.
So I'll be an outlaw till I get it to pass

 

Try dumping some fuel alcohol in the tank prior to your next test.