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Been here for years, and keep going over the same questions time and again, so I thought I would try and consolidate some thoughts in one place. This is meant as an informational post, not a debate over one solution vs another. This will tell you what you can safely remove, and what you will need to do to go further. It also gives some basic info on the CCC system- what components are involved and what they do.

So you want to remove all that "SMOG" stuff. Maybe you want a cleaner looking engine bay, or think it will improve performance or mileage. Here's the scoop-There's SMOG stuff and then there's an ECM managed Engine Control system. They are two separate systems, that have only a slight interaction.



Disclaimer: Smog equipment is a Federal Requirement, and removal is a federal crime. Just because your state doesn't inspect for it doesn't mean it is legal. That being said, many do it.

So what can be removed safely without affecting the ECM.
The AIR pump, and all it's associated piping, hoses, vac tubes, belt, etc.
The CAT.
The EFE valve on the passenger exhaust manifold. EFE is used to make cold starts easier, and to help emissions on cold starts.
The EFE temp switch.
The Purge Cannister ( although I don't recommend it). It has no affect on performance, but does provide the tank with a vent. Removing it can cause gas vapors in the garage as well. It can be hidden

If you want to remove/change the Carb or the Distributor, you will have to change both at the same time. This will eliminate all ECM control of the engine, and you'll be on your own for tuning. You will also need a means of controlling your automatic transmission's Torque Converter Clutch (TCC), if you car is so equipped.

Properly working, the CCC carb and ECM will perform as close to fuel injection as it's possible to get with a carb. How? It controls the fuel/air mixture to try and stay as close as 14.7/1 as possible. It adjusts that mixture about 30 times/second, via the Mixture Control Solenoid. Any other carb can only approximate this setting, and can't do it across the entire range of Idle to WOT. The ECM also adjusts your spark advance to maintain optimum performance, and may reduce it if knock (ping) occurs to prevent engine damage- a good thing.

If you wish to save your ECM, here's the parts involved and how they work. IF you are removing the ECM, you can remove all of the following items, as they are no longer being used.

ECM- the brains. Controls Carb fuel mixture, spark advance, EGR, and TCC Lockup on vehicles equipped with it. DOES NOT control HVAC, Cruise, gauges, lights, throttle kicker for AC, or anything else.

On the Carb:
MCS ( Mixture Control Solenoid). Controls fuel mixture. Moves the primary fuel rods up/down up to 30 times per second to achieve proper fuel mixture. No control at WOT- full rich!
TPS ( Throttle Position Sensor) Tells the computer where your throttle currently is, between closed and WOT. Helps determine how much extra fuel to apply, and how much advance on the distributor.
Critical to have good settings on both these devices.
These are both electrical devices, and can fail over time. Failure will set a code in the ECM, and a Check Engine Light.

Distributor is controlled by the ECM as far as advance is concerned. It assumes a baseline of 0 degrees BTDC setting with the 4 pin connector unplugged. It then adds advance per a table in the ECM, based on Throttle Position, Vacuum readings, etc. IF you set your timing too far advanced, by the time the ECM adds timing per it's table, you may be way advanced, and into the "Pinging" range. I've run as much as 6 degrees baseline, but I had the ECM to contol the pinging. Not sure I really got much of a performance boost with the added timing.

O2 Sensor. Once the sensor is warmed up, and the engine is warm, it supplies a voltage signal to the ECM that tells the ECM whether the mixture is too rich or too lean. This is the heart of the control! Headers usually move the sensor further away, and may require a heated sensor to get warm enough to operate.

Knock Sensor Detects engine knock(ping) even before the ear can hear it. Sends a signal to the ECM to slightly retard the timing to eliminate the knock. Happens quickly, and may only be retarded for milli seconds. This is a good thing, as pinging can cause severe engine damage.

CTS ( Coolant Temp Sensor) Reads the coolant temp and reports it to the ECM. ECM uses this info to change mixture depending on engine temp. This does not send info to the gauges- that's a different sensor.

EGR Solenoid- Controls the EGR Valve. Used to allow a small amount of exhaust gas to be re-circulated into the combustion chambers. While this sounds bad, it's actually good. It doesn't affect performance or mileage, but it does make the engine run cooler. It can be eliminated in programming, but expect higher running temps. Only works when engine is warm, and above 2000 RPM ( IIRC)

EGR Valve: controlled by the solenoid. Over the years, can get clogged up with carbon. Many posts on the site on cleaning/repair.

MAP sensor. Measures the manifold vacuum. Used by the ECM to control mixture and timing adjustments.

BARO sensor- looks EXACTLY like the MAP sensor, but it measures Barometric Pressure ( basically, altitude). Helps the ECM adjust when you are travelling from sea level to the mountains, as an example. IT IS NOT connected to a vacuum line. Looks like it should be, but it really should only have a filter on the nipple.

ESC Electronic Spark Control. Works in conjunction with the Knock Sensor to help control the Spark. They are "Tuned" to specific Knock Sensor part numbers, so an engine swap may require an ESC change as well.

Most of these sensors can be positioned remotely, if you want a cleaner look. Just have to extend some wires or vacuum lines.

So my engine's not running well. What should I look for:
1) check for broken/unplugged vacuum lines. Replace any/all that look bad- heck they may be 30+ years old!
2) Look for stuff "unplugged/removed" by a Previous Owner. Understand how that might affect your sytem.
3) check for any "Codes". Easy to do, even with just a paperclip. http://www.elcaminocentral.com/showthread.php?t=27196
4)If you have codes, track them down. For the cost of a sensor, you may solve your issues. A $20 part can be costing you a lot of money in gas, as well as poor performance.
5) Many times, a Carb Rebuild seems like the best idea. You can do this yourself, with some research. If you decide to have it done, go to someone who really knows the CCC carb, like Mountain Man carbs. There are also others. DO NOT go to your local mechanic unless he can vouch for being a CCC expert. Many have never even seen one of the these carbs, and although they mean well, they can make a mess of it.
6) If you get the carb rebuilt, a final "tune" on the car is a good idea- again research how to do it. If you just go in and start turning screws, you'll be disappointed. There is no way to do it without a dwell meter and the proper tools! Period!.

Thanks for reading, and post questions if there is something you need help understanding. If you have other questions concerning a swap, probably best to start your own thread.
 

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Knock Sensors. Love where they buried da suckers in da LS1. :let_it_all_out:
 

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An excellent post as it is a topic that comes up often.

One thing I would add that often doesn't get said.

Most of the emissions gear has a negligible effect on performance, and the biggest hit to performance in a smog motor is not a piece of smog gear. I can however relate to the cluttered look that comes with all that equipment, it does add weight, and its not terribly attractive.

So lets look at the equipment and its effect on performance.

The AIR pump, and all it's associated piping, hoses, vac tubes, belt, etc.:
This piece of equipment hooks up after the combustion process just outside the exhaust valve, its only drag on the motor is the cost to spin the pump itself, and the chance of vacuum leaks. Take the belt off one of these pumps and spin the pully by hand. the AIR pump draws less HP than your water pump, or alternator and tons less than an AC compressor. this system though also tends to be the ugliest of all the systems.

The CAT:
9 times out of 10, if there is a real drag on the engine from an emissions componant, its the CAT. Early ones were highly restrictive even when brand new, especially the old pellet convertors. Thankfully there are modern ones now that are significantly less onerous on performance. The CAT is usually the worst offender.

The EFE valve:
This item, when functioning properly isnt any power robber, however when not functioning properly can be not much less effective than a potato in the tailpipe.

The temp switch:
is just ugly.

The purge canister:
There is more benefit to having it than not IMO and I think the OP makes that clear.

EGR:
Despite claims otherwise, a properly functioning EGR shouldn't have any noticeable negative effect on performance, when operating properly it isn't used at WOT meaning it doesn't hinder peak performance, also when working properly and with good timing, at cruise it will provide some detonation protection.

The biggest culprit in the smog era though, is not an emissions device but rather the wimpy, slow and power robbing timing curve these motors are equipped with.

Take the 1980 LG4 305 as an example. The HEI in this motor delivers a maximum of 20 degrees mechanical advance at 3800-4000 rpm (an rpm decidedly higher than cruise RPM), add to that the anemic 4 degrees initial and this motor at WOT is retarded 12 degrees from what is generally considered to be optimum timing for a small block. At cruise you can add in the 15 or so degrees from the vacuum advance for a total of 39 degrees, but at cruise a small block operates optimally around 50 degrees...

Fixing that alone will get you more power than any amount of smog gear disconnection short of replacing/removing a plugged CAT. It wont however, clean up your engine compartment.

It is possible to make power with your emissions gear connected, it wont be earth shattering power I grant you, but a 350 with all the gear above can make above 300hp, still pass smog, and will be a hoot to drive.

If you are removing it to clean up the engine bay, I can totally relate, I've been there. If you are removing it for a big performance gain, you will likely be disappointed.
 

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very nice writeup, good paragraph structure separating out the various elements and explanations

even I was able to understand it! bonus points for Darbysan!

as someone else pointed out, this should be a sticky!
 

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An excellent post as it is a topic that comes up often.

One thing I would add that often doesn't get said.

Most of the emissions gear has a negligible effect on performance, and the biggest hit to performance in a smog motor is not a piece of smog gear. I can however relate to the cluttered look that comes with all that equipment, it does add weight, and its not terribly attractive.

So lets look at the equipment and its effect on performance.

The AIR pump, and all it's associated piping, hoses, vac tubes, belt, etc.:
This piece of equipment hooks up after the combustion process just outside the exhaust valve, its only drag on the motor is the cost to spin the pump itself, and the chance of vacuum leaks. Take the belt off one of these pumps and spin the pully by hand. the AIR pump draws less HP than your water pump, or alternator and tons less than an AC compressor. this system though also tends to be the ugliest of all the systems.

The CAT:
9 times out of 10, if there is a real drag on the engine from an emissions componant, its the CAT. Early ones were highly restrictive even when brand new, especially the old pellet convertors. Thankfully there are modern ones now that are significantly less onerous on performance. The CAT is usually the worst offender.

The EFE valve:
This item, when functioning properly isnt any power robber, however when not functioning properly can be not much less effective than a potato in the tailpipe.

The temp switch:
is just ugly.

The purge canister:
There is more benefit to having it than not IMO and I think the OP makes that clear.

EGR:
Despite claims otherwise, a properly functioning EGR shouldn't have any noticeable negative effect on performance, when operating properly it isn't used at WOT meaning it doesn't hinder peak performance, also when working properly and with good timing, at cruise it will provide some detonation protection.

The biggest culprit in the smog era though, is not an emissions device but rather the wimpy, slow and power robbing timing curve these motors are equipped with.

Take the 1980 LG4 305 as an example. The HEI in this motor delivers a maximum of 20 degrees mechanical advance at 3800-4000 rpm (an rpm decidedly higher than cruise RPM), add to that the anemic 4 degrees initial and this motor at WOT is retarded 12 degrees from what is generally considered to be optimum timing for a small block. At cruise you can add in the 15 or so degrees from the vacuum advance for a total of 39 degrees, but at cruise a small block operates optimally around 50 degrees...

Fixing that alone will get you more power than any amount of smog gear disconnection short of replacing/removing a plugged CAT. It wont however, clean up your engine compartment.

It is possible to make power with your emissions gear connected, it wont be earth shattering power I grant you, but a 350 with all the gear above can make above 300hp, still pass smog, and will be a hoot to drive.

If you are removing it to clean up the engine bay, I can totally relate, I've been there. If you are removing it for a big performance gain, you will likely be disappointed.

another good read and good info , I ask and I got , this is a great place to hang out and learn . thanks to every one and all the info I was given . it help me and will think the best and cheapest way to go. I believe it will help others also. not many forums on the internet will make you welcome , and give out great info. with out making you feel like you ask a dumb question , I have always thought that there is no dumb question , except the one that was not asked . thanks Guys ....ya'll Rock .....Don:You_Rock:
 

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The initial post and the follow up by fauxrs really help put things into perspective when it comes to the emissions system. I have kept mine because I want to stay as original as possible. Now I know what it does and does not do.
 

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Great job this will help a lot of members.:You_Rock:
 

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Great info friend! Got a question about one thing though now. How do I go about the plug that is on the driver side of the transmission? I want to say its the TCC you speak of which is attached to the ecm harness. Thanks for the help fella!


Sent from my SAMSUNG-SM-G891A using Tapatalk
 

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