Carbon monoxide

Topic: Carbon monoxide (Read 1550 times) previous topic - next topic

Carbon monoxide

September 09, 2012, 02:45:06 PM

I have to take my car in for emission testing. On line I have been looking at the emissions history of my cougar. What I have noticed is that the last couple of years I have barely squeaked by on loaded carbon monoxide (standard being: 1.20 and my car tested at 1.17). I'm concerned because I just took the top end of my engine (intake manifold on up) and cleaned out all the build up. I noticed that my crank vent element was clogged shut and my PVC valve was stuck, so I have replaced both. Truthfully, I am totally in the dark about emissions, as to is advancing timing helpful or retarding the timing. Would high octane gas better to test with or low octane, or does it matter. What I would like to know is what can I do to bring down the loaded carbon monoxide reading. Carburetors sure used to make it easy, just leaning it out. Thanks!

Carbon monoxide

Reply #1 – September 09, 2012, 03:10:40 PM

Cleaning the throttle body and making sure that the EGR and PCV are working correctly... and all of your emission gear for that matter, is all you can do. Good luck!

Carbon monoxide

Reply #2 – September 09, 2012, 05:58:30 PM

Retarding the ignition timing will bring down the HC numbers. The CO is to much fuel. If it is to high that means you are running RICH. This can be caused by many things. Sounds like your CAT just may need replacing. Check fuel pressure. If that is OK you might have a bad O2. But leaky injectors a dirty air cleaner and a bad PCV system or contaminated oil will drive up your CO. Normally i pull the PCV valve out of the valve cover or the back of the engine and that reduces the CO Dramatically. Never go for an emission test with old OIL On anything other than an OBD2 vehicle. Good luck!!

Carbon monoxide

Reply #3 – September 09, 2012, 06:13:12 PM

My Hydrocarbons (HC) have always been well within limits. My Carbon Monoxide (CO) under load barely squeaks by. The sticker on my car for idle speed and degrees timing has been gone for some time, so I'm not too sure what it is. I usually set it by ear then test run it. Sounds like retard it by 2 degrees and unplug my little grey plug. As tough as they are here in Arizona, I bet they'll be looking for that. Thanks!

Carbon monoxide

Reply #4 – September 09, 2012, 06:15:51 PM

Pull codes.

Carbon monoxide

Reply #5 – September 09, 2012, 07:29:10 PM

I have no idea of what the static timing is on an '86, but on the '88 5.0, the static timing(with the spout removed) is 10deg. before TDC. This of course assumes no slop in valve train and the cam is/was timed correctly in the first place. I know that on my '88 5.0 LX, changing the timing set and dialing in the cam changed the timing enough that you would have thought the car had been blessed with a new motor. She ran like a stripe tailed ape, not like an HO conversion, but significant enough.

Carbon monoxide

Reply #6 – September 09, 2012, 07:52:27 PM

If I remember right, 10 degrees before top dead center w/spout removed sounds right.

Carbon monoxide

Reply #7 – September 09, 2012, 10:39:22 PM

Thats great but timing normally does not effect CO!!!!!

Carbon monoxide

Reply #8 – September 09, 2012, 11:25:59 PM

Quote from: TOM Renzo;397880

Thats great but timing normally does not effect CO!!!!!

You are right Tom, of course. Timing itself can effect HC numbers, but slop in the valve train, can also leave unspent fuel which would result in higher than normal CO numbers.

Carbon monoxide

Reply #9 – September 10, 2012, 04:40:07 AM

Change your fuel filter, do a basic tune up, and get it tested.

We have graduated from a "dyno test" back to a idle and 2500rpm stationary test here in utah. With no load on the engine its almost impossible to fail. With 30k on the same oil and 3 year old spark plugs, I hit .066% with a max of 1.2% on idle and .229% with a max of 1.2% on the 2500rpm test. This was also with one plug wire off of the #7 cylinder that I found broken after the test. I also have a slight ramdom miss while driving, but it throws no codes.

Carbon monoxide

Reply #10 – September 10, 2012, 05:52:47 AM

Quote from: haystack;397894

change your fuel filter, do a basic tune up, and get it tested.

We have graduated from a "dyno test" back to a idle and 2500rpm stationary test here in utah. With no load on the engine its almost impossible to fail. With 30k on the same oil and 3 year old spark plugs, i hit .066% with a max of 1.2% on idle and .229% with a max of 1.2% on the 2500rpm test. This was also with one plug wire off of the #7 cylinder that i found broken after the test. I also have a slight ramdom miss while driving, but it throws no codes.

Why do i find this so fascinating. You are telling people you passed an emission test with a dead cylinder. Then post the numbers that are very low. This is the silliest thing i have ever read in my life. Explain to me how this is POSSIBLE. I would love to KNOW HOW YOU ACCOMPLISHED THIS. And posting that an UN LOADED engine will never fail is beyond imagination at best!!!

Carbon monoxide

Reply #11 – September 10, 2012, 05:59:09 AM

88 i respect your answer but the valve timing when retarded decreases sweep compression which in turn actually can lower emission numbers. We actually installed a timing belt one tooth off in emission school to retard a cam by app 16* It reduced the HC by 14% Most engines can run much better with a cam advanced. But advancing a cam INCREASES HC. Just saying!!

You can try running on regular gas and adding rubbing alcohol yes the kind you can buy in your local grocery store at a ratio of 1:3.5.

This will reduce HC

Carbon monoxide

Reply #12 – September 10, 2012, 02:25:21 PM

Really, I think I'm good to go. New spark plugs, MSD distributor, 8.5 plug wires, gas filter, PVC valve, crankcase vent element and cleaned my K&N air filter and fuel injectors (two new ones). All I need to do is set the timing to (

degrees before top dead center and pull the grey plug. It past all those other times with a stuck (open or shut??) PVC valve and dirty crankcase vent element, dirty intake manifold, grey plug plugged in, and the timing was probably set a little advanced, so hopefully every thing should work like it's supposed to. I've heard about the rubbing alcohol trick before, but I won't do that. Thanks!

Carbon monoxide

Reply #13 – September 10, 2012, 07:27:53 PM

Hat you asked not me!!!!

Carbon monoxide

Reply #14 – September 10, 2012, 09:23:56 PM

Quote from: TOM Renzo;397896

Why do i find this so fascinating. You are telling people you passed an emission test with a dead cylinder. Then post the numbers that are very low. This is the silliest thing i have ever read in my life. Explain to me how this is POSSIBLE. I would love to KNOW HOW YOU ACCOMPLISHED THIS. And posting that an UN LOADED engine will never fail is beyond imagination at best!!!

The emissions requirements for the idle and rev test are now almost twice as high as they were for the dyno test. I have only had one engine fail an emissions test before, and that engine had 297k on it and used 4 or 5 quarts of oil a tank. A basic tune up is all 90% of cars that won't pass need.

The year before, max was .89% and my car read 0.0-0.01% for the two years previously. This year the car has developed a miss and stutters badly at certain rpm's. Running codes pulls nothing up(minus a non-functioning egr), and I don't want to put any money intol it to fix it this year, as it might be going away and replaced.

If you wan't I will show you the emissions papers.