Can I remove my ODB1? (not a legal question)

[jiho]

All I can say about OBD1 is this...

if you take out the ECM, take out or disable ALL of it. You can't just do a partial. It's not hard, but previous posts explain the things needed to do it. Older carbs and vacuum distributor is in your future. If OG old school is what you want, don't install anything you need a computer for.

Bottom line.

On the potential of OBD1, I offer the following additional comments.

There's a fundamental catch-22 between efficient burn and NOx. That's what tripped VW up with their diesels, and why the EPA and California have different tailpipe standards. The lower the unburned and partly burned fuel -- HC and CO -- the higher the NOx, and vice versa. This is because higher combustion temperature burns more fuel but also creates more NOx, and lower combustion temperature reduces NOx but also burns less fuel. The EPA favors burn efficiency at the expense of higher NOx, California favors lower NOx at the expense of burn efficiency.

At the time OBD1 appeared, regular unleaded was the new normal and super unleaded was hard to find, so Detroit favored lower compression. Lower compression meant lower NOx, but also less efficient burn. Improving burn efficiency meant either hotter ignition or higher compression, either of which meant more NOx. While Detroit dragged its feet on fuel injection systems, California came up with an elaborate "NOx credits" quota system to allow some of the many cars that couldn't meet the California burn efficiency and NOx standards all at the same time into the state under the EPA standards.

As delivered off the assembly line, the 1983 Buick V6 was BARELY passing the California standard on all three points -- HC, CO and NOx. In my area only HC and CO are tested, but to get mine to show low numbers with California gas, I had to increase spark temperature to the point where the plugs started to melt. NOx must have been through the roof.

EGR is a form of "fake compression" that supposedly lowers HC and CO without raising NOx at off-idle, where you do most of your driving. My Buick also showed low numbers when EGR was disabled, but again NOx must have been through the roof, and anyway it flunked the visual.

Detroit did not start delivering cars that could perform well and meet all the standards until they bestirred themselfs to implement SFI. Initially these cars still used OBD1. Many still had distributors.

The OP doesn't care about any of this, of course. But hopefully it provides some background for what he and many others are looking at.

 

[Clone TIE Pilot]

Bottom line.

On the potential of OBD1, I offer the following additional comments.

There's a fundamental catch-22 between efficient burn and NOx. That's what tripped VW up with their diesels, and why the EPA and California have different tailpipe standards. The lower the unburned and partly burned fuel -- HC and CO -- the higher the NOx, and vice versa. This is because higher combustion temperature burns more fuel but also creates more NOx, and lower combustion temperature reduces NOx but also burns less fuel. The EPA favors burn efficiency at the expense of higher NOx, California favors lower NOx at the expense of burn efficiency.

At the time OBD1 appeared, regular unleaded was the new normal and super unleaded was hard to find, so Detroit favored lower compression. Lower compression meant lower NOx, but also less efficient burn. Improving burn efficiency meant either hotter ignition or higher compression, either of which meant more NOx. While Detroit dragged its feet on fuel injection systems, California came up with an elaborate "NOx credits" quota system to allow some of the many cars that couldn't meet the California burn efficiency and NOx standards all at the same time into the state under the EPA standards.

As delivered off the assembly line, the 1983 Buick V6 was BARELY passing the California standard on all three points -- HC, CO and NOx. In my area only HC and CO are tested, but to get mine to show low numbers with California gas, I had to increase spark temperature to the point where the plugs started to melt. NOx must have been through the roof.

EGR is a form of "fake compression" that supposedly lowers HC and CO without raising NOx at off-idle, where you do most of your driving. My Buick also showed low numbers when EGR was disabled, but again NOx must have been through the roof, and anyway it flunked the visual.

Detroit did not start delivering cars that could perform well and meet all the standards until they bestirred themselfs to implement SFI. Initially these cars still used OBD1. Many still had distributors.

The OP doesn't care about any of this, of course. But hopefully it provides some background for what he and many others are looking at.

Also the G body platform lasted longer than expected. GM originally planed to discontinue G bodies in the early 80s but due to delays with the development for W bodies, they were extended to the late 80s. So other than turbo Regals, GM was not interested in spending money on G body updates. Even the Buick V6 had a host of updates in the very first year W bodies replaced G bodies. The only reason GM made ZZ4 chips is because they were part of the 350 swap package for CCC F bodies.

The CCC system has 4 modes, cold start mode called open loop, warmed up mode called closed loop, lean burn mode at cruising speed, and power enrichment mode at high throttle openings for passing power. This means at WOT the carb goes into full rich, fully mechanical mode. In simple terms, just crusing the computer controls the fuel mixture for best gas mileage, when you punch the computer defaults to full rich for a temporary power boost.

The CCC ECMs can be tuned but its not easy. Crane Cams used to make aftermarket ECMs in the early 90s for CCC cars that had trimpots and dials to adjust thd tune. However, most hotrodders back then were not knowledgeable or interested in computer tuning, so the adjustable ECMs are rare.

A second way is to burn your own custom PROM chips with free tuning software like Turnerpro. Problem is the CCC ECMs use a unusually type of PROM chip that was kind of like Betamax. Its hard to find blank ones now. However, there are a few people who burn CCC PROM chips for sale such as Bitflipper's hybrid ZZ4 chip he sells over on Montecarloss. Even those require using a 87 or 88 ECM and only works for SBC CCC cars. I have his chip and it is an excellent upgrade.

 

[jiho]

The CCC ECMs can be tuned but its not easy. Crane Cams used to make aftermarket ECMs in the early 90s for CCC cars that had trimpots and dials to adjust thd tune. However, most hotrodders back then were not knowledgeable or interested in computer tuning, so the adjustable ECMs are rare.

A second way is to burn your own custom PROM chips with free tuning software like Turnerpro. Problem is the CCC ECMs use a unusually type of PROM chip that was kind of like Betamax. Its hard to find blank ones now. However, there are a few people who burn CCC PROM chips for sale such as Bitflipper's hybrid ZZ4 chip he sells over on Montecarloss. Even those require using a 87 or 88 ECM and only works for SBC CCC cars. I have his chip and it is an excellent upgrade.

When I was looking into laptop-based scantool software, I found an ALDL definition file somewhere that claimed the '83 Buick V6 (NA, anyway) used an 80 baud bit rate on the data line, instead of the 160 baud bit rate used by all the other early ECMs. Do you know anything about that? Not sure I want to.

 

[Clone TIE Pilot]

When I was looking into laptop-based scantool software, I found an ALDL definition file somewhere that claimed the '83 Buick V6 (NA, anyway) used an 80 baud bit rate on the data line, instead of the 160 baud bit rate used by all the other early ECMs. Do you know anything about that? Not sure I want to.

As far as I know all the early GM ECMs were 160 baud. The 80/81 systems were cruder than the later years. In 87 they upped the voltage but the baud rate remained at 160.

I am not surprised about Buick V6s barely passing tests. When I swapped my old Buick V6 for the HO 305, I was surprised the HO 305 had a much shorter cat converter than the V6. Guess the 305 burns cleaner and requires less converter despite making 70 to 80 more HP. Buick V6s really are dogs, no wonder it took intercooled turbocharging to get decent power lol.

 

[abbey castro]

I run a ZZ4 (came with HEI) Running an Edelbrock Q-Jet. Took out the complete CCC setup, the harness entry into the pax floor is pugged by sheet metal cut to fit the opening, held in place with screws. All the other electronic pieces that make the system came off. Cruise Control will not function, but my foot is calibrated. The ZZ4 uses only some connectors that are the basic wiring to make it run.

 

[jiho]

Guess the 305 burns cleaner

Higher compression.

 

[Clone TIE Pilot]

Higher compression.

Also better flowing heads.

 

[MrSony]

DO NOT RIP OUT THE AC BOX.
I swear if I see another post about that...
People always do it then complain when they cant see. Keep it.

 

[69hurstolds]

Good point about losing cruise on 84-88 cars with K34. I forgot about that. I hadn't studied 81-83 cruise stuff, though. The ECM controls the vacuum/vent ports for the servo and uses the inputs from the VSS buffer (green thing behind the speedo) to know how fast the car is going as well as knowing what the stalk switches are doing. If you really wanted cruise, I guess you could adapt a pre-CCC cruise unit to the car. Or you could disable wires that only go to the other junk. I've never had the need to remove the CCC system, and I'd rather not on any of my cars.

If I were modifying for big HP though, I'd rip that thing out by the roots.

 

[cloudhome]

There's a check engine "driver" that will illuminate the check engine lamp when you remove the computer. The driver is a small (maybe 1" x 2.5") PCB that plugs into the wiring harness on the passenger side of the dashboard. Easy to locate and remove if you pull the glove box door and look to the right. Just pull the PCB out.
Of course the computer controls the carb and spark advance, so you'll need to have those controlled by another method. I used an Edelbrock carb and a new Accel distributor with vacuum/counterweight advance.