I am planning an upgrade to the intake side of my '86 Elky. It has the usual 305 w/ 4 bbl carb. Engine is currently completely stock. It's equipped with auto trans, AC and cruise. The upgrades I am planning are an Edelbrock performer intake and an Edelbrock 650 CFM spread bore carb. I will also pull the heads and have a shop perform a basic valve job and replace any worn parts at that time. I will keep the stock distributor and freshen it up with new cap, rotor, and plug wires. Later, I plan to get some shorty headers, but that won't be part of this particular project. My question is about the smog pump and the electronic controls. How much of these items can I remove (pump, O2 sensors, various electronic carb hook ups)?There is no emissions testing in my area, and I believe the Elky is old enough to get by anyway. This Elky is the newest Chevy I have ever planned to wrench on, and I am a bit in the dark on the emissions and the electronic controls. I want to clean up my engine bay, and cut down on power loss that I'm sure the pump is giving me. Also, I'm very much in the dark on the electronic components of my stock carb, so any help would be much appreciated.

You can remove pretty much all sensors except the ones that send iformation to your gauges. You'll also have to change the ditributor if you plan on ditching the computer setup.

So I take it the distributor is connected to the ECU?
If thats the case, then I can either switch to a older GM HEI unit, or a new aftermarket one. I have a GM HEI with a new cap and rotor from a '77 Elky, so that may work, although not as good as a high power aftermarket unit. Any recommendations?
Also, from searching old threads, I have read that the ECU controls the torque converter lock up as well. Any ideas on that?

You can wire that lockup to a switch on the inside of the truck or Bowtie overdrive and I think TCI sells a kit for retro-ing a 700R4 and 200R4s into older cars and trucks. I think Painless Wiring also sells the kit. So the lockup can be done without the ECU.

I'd go with MSD, I did on the 76 El Camino and never looked back. On my 80 ss I got a New Billet HEI Distributor with something called a Flame Thrower Ignition module and Coil. Looks like a regular GM HEI, my MSD doesn't at all. I can't say much about my 80's performance because its just not finished and running yet. It will be nice, I doubt that the ignition will give me grief.

The MSD is the one with the most pieces to it. I guess if you take into consideration what all its doing then its alright. Mine uses the external Blaster II Coil and MSD 6A Controller box. I essentially gutted my stock GM setup and installed a wire bundle in it for the MSD. Well, two wires that connect directly to the HEI magnetic pickup and by passing any internal EM in the cap.

Fires great works great. I suspect most after market ignitions are pretty good and much improved over any stock GM HEI Application its almost always worth the change. With the MSD you gain not only better firing but the plugs last longer, some improvement in economy and better cold weather starting and at the high end your only pretty close to limited by your engine's ability to spin. Ignition at Higher RPMs over 5000, where GM's brake down is flawless up to 9000 I think the MSD limit is for mine anyway.

Its something to think about.

The engine timing on your 86 is controlled by the on board computer. You call it the ECU. Actually, you can disconnect the O2 sensor, remove the AIR tubes, the AIR pump, the heat riser valve, the EGR valve and all the hoses connecting these devices to the vacuum system and the engine will run just fine. However, the "service Engine" light will be illuminated all the time. If you want to use the same distributor, do not disconnect the ECU and it will work just fine. I know. I did it once upon a time. However, you will not pass emissions testing when it comes to your area, and it will. If the Fed does not force testing, the local politicians will in an effort to raise money. If you decide to remove the emissions controls, be careful not to damage them during removal and store them in a safe place. Make a drawing and detailed notes about where each component came from so when you reinstall them, it will be easy to do. I believe you will be forced to reinstall them because emissions testing IS COMING TO YOUR AREA sooner or later. If you save the components, you will save a lot of money if you have to reinstall them later.

So, if you want to keep the same distributor, be sure to keep the ECU connected.

The following info may be of interest to you: The ECU receives input from the Oxygen Sensor and uses this input to adjust the Mixture Control Solenoid (m/c solenoid) in the e-carb (E4ME). This solenoid controls the rich/lean fuel mixture to keep emissions at a minimum. It also helps gas mileage by avoiding a fully rich mixture 100% of the time. The e-carb also has a Throttle Position Sensor (TPS) that controls the lock up torque converter.

You can keep the ECU, the HEI distributor, the e-carb, the O2 sensor and the EGR valve while removing the other stuff and the engine will will run very well indeed. You must seal off all the unused vacuum ports. If you have a functioning catalytic converter, I suspect the engine would pass the emission sniffer test, but not the visual inspection. I cannot verify it would pass the sniffer test, but don't see why not.

Just be sure to think ahead about what you will need to do if and when emissions testing comes your way.

Thanks for the input guys. That's a lot of help. I sure didn't want to indescriminately yank parts off the Elky without knowing the impact. Looks like I'll for sure remove the pump. I'm currently running cat free since I have duals with 40 series Flowmasters. Spoon, you may be right about the emissions testing. It's only a county away right now. I'm just hoping that by the time it reaches here, older vehicles will be exempt. Still, I will save all parts, as I never throw any cars parts away unless it's trashed.

If you suspect emmissions testing is coming your way soon, why not just cut the belt on the air pump and leave it in place. One less thing to replace when the time comes.

As far as age to avoid testing, here's what I know: In North Carolina it's 1978 and earlier. In Tennessee, it's 1975 and earlier. I do not know of anyplace in the country that will exempt an 86.

Well, I'd really like to clean it up under the hood and get rid of a lot of the extra hoses, lines, etc. I mean, I can't even see the passenger side valve cover for all the smog junk. Plus, all that stuff has to weigh a few lbs. too. Yes, I will keep the parts, but I don't think I'll have to worry about emissions testing in this rural county for a few more years.

You can pull all those little vacuum hoses that run to and from the Cannister Control Valve, seal off the vacuum ports on the carb, and the vehicle will run fine. You will no longer be bothered with the AIR tubes and all those little vacuum hoses. Removing those little vacuum hoses is where careful, detailed notes and a very well drawn hose schematic should be done. The hardest part to restoring the emissions system is determining where each of those little suckers plug in. There's two Thermal Vacuum Switchs (TVS) in the intake manifold immediately beside the thermostatthat that operates the Heat Riser Valve and the Cannister Control Valve. The heat riser valve is located in the exhaust pipe beside #8 cylinder. The Cannister Control Valve is that plastic thing directly over the thermostat with all those vacuum hoses connected to it. Leave each TVS in place, but cap them off so no debris gets inside them. Be sure to carefully label each port on the Cannister Control Valve when you remove it. Do all these things plus any I have overlooked, and reinstalling will be a snap if and when your are forced to do it.

Thanks for the info. I'll probaly take lots of digital pics and store them in my "elky file" along with all my other car documents as well. A few good pics can make all the difference in the world should I have to reassemble the emissions system. Meanwhile, I'm looking forward to a much cleaner and uncluttered engine bay. 8)

I honestly do not think you will see a performance improvement.
However, there MAY be an improvement in fuel mileage, but I am not certain. The best result will be the improved ease of changing the spark plugs, especially #8. IF both the heat riser vacuum actuator and AIR tubes are out of the way, working in that area gets a little easier. The heat riser vacuum actuator is bolted onto the body of the heat riser with one 7/16 x 1/2 inch bolt. Spray it with penetrating oil for 3 or 4 days and use a pair of heavy gloves to loosen the bolt. The gloves will save you a skinned knuckle when the bolt finally decides to turn.

I wouldn't bother saving any emissions crap especially air pumps. Who wants a component that was designed to cause backfire! The older ones like what was on my 74 were absolute garbage.

Anyway if I lived in an area without emissions nazis I'd probably have as much fun with my Elky as I could and save my pennies.

Then when the emissions nazi's came around I'd yank out the 80's vintage motor and go get a nice LT1 or LS1 with all the emissions crap in place already. Then I'd drop it in and thumb my nose at the emissions nazis.

I hate emissions testing...The pick on the wrong people...especially when I got cop cars running around my neighborhood belching black smoke....

...damned emissions nazis.....


...damn them all to hell!!...

8O :)

I wasn't really expecting much performance gain from removing the smog stuff. I mainly just want a cleaner engine bay. I took the belt off the air pump and drove around for awhile Saturday just to gauge the effect. When slowing down from highway speed, at approx 10 Mph, the engine "dieseled" and clattered some. I thought it might stall, but it quickly straightened up. I assume it was the electronic controls on the carb causing this. Once I remove all that, I'm hoping that will not be a problem.

I never heard anyone say an engine would "diesel" while it was actually running. I thought "dieseling" was an engine trying to keep running after the ignition key was turned to the "off" position. The AIR pump would have no affect on the performance of the engine. It's sole purpose in life is to pump air into the both exhaust manifolds and the catalytic converter to lower the undesirable emissions gasses.

Performance issues you mentioned sounds like a vacuum leak to me. I see no reason to think the M/C solenoid in the carb would cause it to run like you describe. It's job is to control the lean/rich mixture by moving the metering rods inside the carb.

You are correct in your definition of dieseling as an engines attempt at running after shutting it off. However, since this is exactly what it sounded like, that was the best way I could describe it. I did change all of my drive belts Saturday, so it is possible I may have accidentally disconnected a vac line. It didn't make logical sense to me either that disconnecting the air pump would cause any issues with the engine running smoothly. I was hoping that the computer was not trying to compensate with the lean/rich mixture on the carb. Apparently, then, disconnecting the air pump does not cause the computer to change the mixture, so that's a good thing. I'll check those vac lines soon. I'll bet something got pinched or knocked loose when I was servicing the car.