removing electronic crap

Has any one removed the command control computer for the 80's caprices and had any luck? I would really like to drop in a zz4 crate engine and switch to a holley. I just recently moved to a township that doesn't require smog testing so I'm really excited about that. Does anyone have any tips to remove this system? (i.e. computer location, removal of the smog pump, ETC.) any help would be great.

Do some homework. Many people have retrofitted ZZ* engines into vehciles with CCC systems and retained the system, actually doing better than a standard carburetor and mechanical/vacuum distributor. This binary file is a good start to ZZ3/4 programming:

ZZ4-CCC-ESC.bin (http://www.moates.net/files/1)%20Stock%20Binaries/ZZ4_CCC_ESC_24502456.BIN)

People who have tried to replace the QuadraJet with an "equal" Holley or Carter have learned the hard way that they never quite get them tuned right for both street manners, mileage, and track power.

Then there is the futile attempt to try to curve a distributor better than the spark tables in the program. A mechanical/vacuum distributor is nearly impossible to set up to bring on heavy advance at low RPM/light load, maintain it at low RPM/heavy load, then back it off at middle RPM/heavy load, and bring it all back on at higher RPM, all while raising it even higher (like 50°) at moderate RPM/light load cruise. There just isn't a vacuum advance unit that can remove centrifugal advance degrees at moderate vacuum and middle RPMs. Since that is appropriate for most SBCs, the spark tables can easily be programmed that way. You'll spend the rest of your life trying to emulate that with a mechanical/vacuum distributor.

Then there's the fuel map. Good luck with that and a Holley. You'll spend as much in jets, power valves, bleed tubes, and taller/shorter venturi pods as you did on the carburetor and intake, and still never match it.

Search before you buy.

Holley makes a model 4175 spreadbore carb. I bought it for my Camaro a few years ago and it was a great carb. No complaints at all. Direct replacement for quadrajets. Summit Racing sells them.

Cheers

Has any one removed the command control computer for the 80's caprices and had any luck? I would really like to drop in a zz4 crate engine and switch to a holley. I just recently moved to a township that doesn't require smog testing so I'm really excited about that. Does anyone have any tips to remove this system? (i.e. computer location, removal of the smog pump, ETC.) any help would be great.

More power to you and good luck with it.
But even thow you have got out of the smog check zone.
The EPA laws and the clean air act of 1990 still covers alot of stuff on them from 1980 up.

Here is a little info and reading on it. MT

http://www.epa.gov/air/caa/caa203.txt

Run a search under federal emissions laws or the Federal clean air act

http://www.novak-adapt.com/knowledge/emissions.htm

Emissions Laws
The Federal Clean Air Act as amended in 1990 has extended the prohibition against removal or rendering inoperative vehicle emissions control devices by the consumer. Changing an engine or even a transmission in a vehicle may change its pollution status and render it illegal for street or even off-road use on lands that are covered by emissions laws. This usually applies to later model vehicles and this, along with other pertinent laws vary from state to state. Generally engines and associated emissions controls from vehicles that are the same year or newer vintage as the vehicle to which they are being converted are legal swaps. However, it is the owner's responsibility to investigate the smog laws and determine that any changes you make to your vehicle will not cause it to be in violation of any state and federal regulations.

Many often ask about the difficulty of installing late model engines, especially those which are OBDII compliant - which includes all engines after 1996. There are some sticky issues involved, but as interest in swaps remains so strong, many resources are available to help decipher it all. We will continue to work in this area so we may be of assistance and offer helpful products to assist with these technologically advanced conversions.

Back to the original post, I've recently removed all the emissions componets, and everything computer controlled in ym '84 Caprice, and it successfully passed inspection (they didn't even bother to pop the hood). Anyway, all that really needs to be done is replace the carb, replace the distibutor with an HEI one equipped with a vacuum advance, and put the TCC on a switch on the dash if you want the torque converter to still lock up. And thats all thats needed to convert the car from a computer controlled vehicle to a non computer contolled one. Of course the later the model Caprice, the more electronic components theres gonna be.

its very simple to do, and the wiring harness to the ECM is separate form all the rest of the wiring of the car, it is over on the far pass side going over to the wheel house and down into the cowl/firewall/fender pocket area

remove the entire thing and the ECM behind the pass side kick panel and after you have installed a non CC HEI and carb then thats it

thousands of ppl do it, very common

in some locations you can get in trouble and others you will be fine

a non CC engine can pass emissions if it is in good shape and has the right parts on it





good luck

When you make your engine non-cc, just tune it ta run a little lean when getting it inspected, then if yah want change it back after you pass :-P

It's a black art to get it to the proper mixture. Too lean and your HC and CO will go through the roof, as will NOx.

Those of you who swear computers are bad will always be behind those of us who embrace them, in speed, drivability and economy. Last night my stock nearly 100K shortblock car went 12.5 107mph NA repeatably about 4250lbs with me and is a daily driver, would not be as pleasant to drive or as fast without the computer. Hell there were S-10s with stroker smallblocks TRAILERED there running slower than I was, every time the weather changes they are screwing with jets and all, where I just get to ra ce and enjoy the show.

Those of you who swear computers are bad will always be behind those of us who embrace them, in speed, drivability and economy. Last night my stock nearly 100K shortblock car went 12.5 107mph NA repeatably about 4250lbs with me and is a daily driver, would not be as pleasant to drive or as fast without the computer. Hell there were S-10s with stroker smallblocks TRAILERED there running slower than I was, every time the weather changes they are screwing with jets and all, where I just get to ra ce and enjoy the show.

That's not to mention that an ECM, even the first generation ones on cars with feedback carburetors such as mine, will still be able to do things to the distributor's advance curve that would be impossible to do with springs and weights. One of these days some of those anti-ECM/PCM people will realize what they're missing by stripping out the ECM.

My old 1975 Grand Am with a Chevy 350 in it, had a 650cfm Carter AFB
on it, and I always had to play with the static advance on the ignition (retard it) and play with the screws and the idle speed on the carb to get it through emissions - usually on the 3rd or 4th attempt. Now, that same engine that was in the Pontiac is now in my Caprice and with the ECM (keep in mind this is with the same Crane PowerMax cam, a large quench area chamber design and all that other emission killing stuff) flies through with no effort on the first attempt. It makes more power, too.

Good run, Dwayne.

"4250 lbs?" Perhaps it's time to do something about that spare tire, and maybe the one in the trunk, too. ;) With a little under ¼ tank of fuel and "junk outta the trunk" I scale in at 4,180. I'm currently slower, too, (lost some ET, trans issue I think) so don't go by what I'm doing.

A few years back I bought a 1985 Caprice classic (5.0L, carb) with the "crap" partially removed....

1. Check Engine light was taken out. Instant disqualification under PA standards.
2. Solenoid in carb was disconnected. Oddly enough the previous owned didn't bother to bust out the "caps" and re-adjust the mixture.
3. Hose for thermostat "snorkle" was blocked.
4. Hose to EGR was blocked off.

He left the Det sensor (which probably retarded the poor thing to heck and back) intact.

Result - Car ran like absolute crap. Catalytic converter was damaged.

I undid all of the preceding and put nice new vacuum hose to replace the GM plastic crap. Rebuilt the carb to spec. Put in a new converter.

The engine had other damage to the valve train. Had to replace the engine. Still not quite right but it's not too bad.

If I were you I'd migrate to a Throttle Body Ignition setup. The TBI ECM for the later years will probably work fine. You'd need an electric fuel pump and new intake manifold too. I would like to do this with my Caprice, since I don't really like those electronic carb things - too slow on the uptake for changes in mixture.


However if you've made up your mind that the technology must go...

Rip out the catalytic converter - you're gonna have to do it sooner or later anyhow. Prepare yourself for pain if you're ever caught without it.

Rip out the smog pump.

Remove the det sensor controlled Distributor and replace it with a mid 1970s vintage HEI. Get one from before the "Transmission Spark Control" era. Set the timing so you don't detonate but get decent performance.

Might as well rip out the bulk of the vacuum hose. Less is more when it comes to potential sources of leaks.

IF you have a "clutch converter" transmission (probably the 250C series) you'll probably need to buy one of those little computer gizmos to control clutch engadgement. Alternately, put in a THD 350.

I really wish you'd reconsider removing the ECM. When you set them up right they are wonderful and best of all you're bulletproof legal.

Gene

I did the same thing to my old '86 K10 with the 350 and 700r4. Junked the factory dist and carb, put a carb from an older chevy on it, hei dist with vacume advance, also got rid of the wiring for all of the crap as well. Keep in mind that I will trip the check engine light.

It's a black art to get it to the proper mixture. Too lean and your HC and CO will go through the roof, as will NOx.

As I recall the "Lean Drop" procedure is as follows (I owned a 1977 Chevy Caprice, a 1975 and 1973 Nova)....

0. Check and eliminate all vacuum leaks. Don't even start until you've done this part. I include this step because I was the guy who often DIDN'T check for leaks - and paid dearly for it.

1. Open primary mixture screws/caps/what have you. Yes, you may need to remove the carb to do this with a hacksaw and/or chisel.

2. Engine must be "warm" - up to operating temperature. Choke wide open.

3. Adjust curb idle to "spec" as seen on the VECL. I used to use 800 rpm with the tranny in park (book says keep the blasted thing blocked at 600rpm in drive... but I don't fancy being run down).

Did I mention you need an RPM gadget? Shoulda...

4. Alternately adjust primary idle mixtures until engine RPM starts to drop, by about 100rpm. Adjust a half turn "rich". My Chiltons says a quarter turn rich at the 20rpm drop point for the carbs I was using. I had a problem with "lump" and couldn't get their proc to work right.

GM used to claim that you can duplicate or exceed this "procedure" by adjusting idle so that Carbon Monoxide is "minimized" by smog test. If you can this do so.

I got my 1977 through emissions checks doing the above "procedure". Before PA exempted everything made before 1980 the checks for these oldsters was a five minute "idle" test. I used to ace the Carbon Monoxide but did really bad on the hydrocarbons.

My Landlord has a trick for adjustment which works really well. Alas, it's by "ear", he claims he can tell "when it drops very slightly". Maybe someday I can get him to show me.

Gene

As I recall the "Lean Drop" procedure is as follows (I owned a 1977 Chevy Caprice, a 1975 and 1973 Nova)....

0. Check and eliminate all vacuum leaks. Don't even start until you've done this part. I include this step because I was the guy who often DIDN'T check for leaks - and paid dearly for it.

1. Open primary mixture screws/caps/what have you. Yes, you may need to remove the carb to do this with a hacksaw and/or chisel.

2. Engine must be "warm" - up to operating temperature. Choke wide open.

3. Adjust curb idle to "spec" as seen on the VECL. I used to use 800 rpm with the tranny in park (book says keep the blasted thing blocked at 600rpm in drive... but I don't fancy being run down).

Did I mention you need an RPM gadget? Shoulda...

4. Alternately adjust primary idle mixtures until engine RPM starts to drop, by about 100rpm. Adjust a half turn "rich". My Chiltons says a quarter turn rich at the 20rpm drop point for the carbs I was using. I had a problem with "lump" and couldn't get their proc to work right.

GM used to claim that you can duplicate or exceed this "procedure" by adjusting idle so that Carbon Monoxide is "minimized" by smog test. If you can this do so.

I got my 1977 through emissions checks doing the above "procedure". Before PA exempted everything made before 1980 the checks for these oldsters was a five minute "idle" test. I used to ace the Carbon Monoxide but did really bad on the hydrocarbons.

My Landlord has a trick for adjustment which works really well. Alas, it's by "ear", he claims he can tell "when it drops very slightly". Maybe someday I can get him to show me.

Gene

Nice. I understand the 'lean drop' method of adjusting the thing. The problem is, with an engine with 'illegal' parts in it (not the cam, but the pistons and other things) the lean-drop method gets it running really good, but HC and CO aren't where they need to be. I don't want you to think that I'm some sort of newbie at this - I started rebuilding engines in some capacity back in '79 so I've been around a while at this :)

The standard for emission testing in Arizona is 1975 and newer - a trip on the chassis dyno and it must pass at idle and a specific RPM under load and no load (the cruise test). 1981 and newer cars get the IM147 test.


Also, keep in mind that the lean drop method adjusts the engine for idle characteristics - it doesn't do a thing for the mixture when the idle circuit is out - this is handled by the jetting.

Nice. I understand the 'lean drop' method of adjusting the thing. The problem is, with an engine with 'illegal' parts in it (not the cam, but the pistons and other things) the lean-drop method gets it running really good, but HC and CO aren't where they need to be.

I lack sufficient experience to comment on this point. However it makes sense, there are many variables in engines.

I don't want you to think that I'm some sort of newbie at this - I started rebuilding engines in some capacity back in '79 so I've been around a while at this :)

Cool.

The standard for emission testing in Arizona is 1975 and newer - a trip on the chassis dyno and it must pass at idle and a specific RPM under load and no load (the cruise test). 1981 and newer cars get the IM147 test.

That's a lot tougher than PA. We're only doing Dyno runs (which I'm told measures NOx) in very limited urban areas.

OBDII cars are interrogated by computer. It's pretty neat unless the machine has an upset, then you either have to drive it clear or get the dealer to clear it. Either way you're out some money.

Also, keep in mind that the lean drop method adjusts the engine for idle characteristics - it doesn't do a thing for the mixture when the idle circuit is out - this is handled by the jetting.

Which would explain why my 1977 used to pass emissions checks, since in PA they were only checking the idle emissions. As of last year there are no emissions checks done on pre-1980 cars.

Gene

Good run, Dwayne.

"4250 lbs?" Perhaps it's time to do something about that spare tire, and maybe the one in the trunk, too. ;) With a little under ¼ tank of fuel and "junk outta the trunk" I scale in at 4,180. I'm currently slower, too, (lost some ET, trans issue I think) so don't go by what I'm doing.


I can't run it that low the pickup goes dry. The only weight I am currently looking to drop is getting some drag wheels for the back the current 2wd Suburban rims are HEAVY want to say 27-29lbs, I can find other steelies at 18lbs not to even get into how little something like a Weld would weigh. Easy tenth there maybe more. AFR is a tad rich yet too and it is pulling 2+inches at the topend, definetely more in her:evillol: .

You obviously know me what other name might I know you by.

Oh and as far as the spare tire I could stand to lose about 20lbs myself, what the activity of working on the car burns off the greasy track food puts back on though:banghead: .