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I have attached a few pictures, my question is does this intake manifold look original and does the carb look original and does it look like it has any issues? Also is there anything that you notice that is not right? The Air pump and emission related items have been removed as well. Thanks for any help you guys can offer. I don't know much about carbs but I am learning as much as I can.
The electrical connections to the carburetor sure point to it being original as such was only used in 1980 (California only) and 1981 (all). The CCC (computer command control) system that operates the carb and distributor had a poor reputation for reliability. I don't know how much of the emissions control system can be removed without causing starting/running/performance to decline.
I'm not sure about the intake manifold but suspect it too is original. The stainless steel exhaust manifolds are certainly original.
The intake and carb look correct; not good enough photo to say about the distributor (1-year only unit which connected electrically via wiring harness to carb, ecu, and sensors).
Do you know (via check engine light) if the ECU is operational or not?
If the system is intact and operational, it is a significant improvement over the non-electronic carb & dist. And you can upgrade the engine internals for more power and still use that engine control system.
Thanks for all the responses. The car actually runs quite well. Just curious to see if the stuff I have is in fact the original stuff. It seems to be a little sluggish...but it also only has 190 hp. As far as I am aware, everything is working properly and functioning as it should. I am in the process of deciding to build a new motor for the car. Thanks again. If anyone sees something else please let me know.
Thanks for all the responses. The car actually runs quite well. Just curious to see if the stuff I have is in fact the original stuff. It seems to be a little sluggish...but it also only has 190 hp. As far as I am aware, everything is working properly and functioning as it should. I am in the process of deciding to build a new motor for the car. Thanks again. If anyone sees something else please let me know.
280 ft/lbs of torque at only 1600 RPM means it should be very quick from a stop.
See this for simple instructions on how to pull the engine codes (you jump two wires and count "Check Engine" light flashes) as well as the meaning of the codes and some good information about your carburetor.
If your "Check Engine" light isn't already on and it works when you use it to retrieve codes then someone knew what they were doing when removing the emission systems. If the "Check Engine" light won't work when you retrieve codes I'll bet the lamp was removed
Some of those vacuum lines are starting to look a little old, so may be starting to leak a little. I would put a proper cap on the one that just has a screw in it. Not sure why you have an empty port at the top of the carb (at the rear) maybe something to do with the auto trans?? I'd have to look at my manual for that one. What's the carb number? (8 digits, drivers side towards th rear) That's the easiest way to tell if it's original. Intake manifold is original.
The ECU on these is a basic unit, it won't notice that any of the smog stuff is gone. So as long as the check engine light works, but doesn't come on when the engine is running then it's fine. You can advance base timing a bit on these to wake them up a little. Most guys go to 10-12*btdc and switch to premium gas.
Mike, thanks for that page, a lot of good info there. Which brings me to my next question, I just jumped the diagnostic ports and I get a 23 code, the MCS. What I also noticed is that the last time I jumped the ports, I heard clicking from under the hood, this time I did not. Any ideas?
Mike, thanks for that page, a lot of good info there. Which brings me to my next question, I just jumped the diagnostic ports and I get a 23 code, the MCS. What I also noticed is that the last time I jumped the ports, I heard clicking from under the hood, this time I did not. Any ideas?
When you say you heard a "clicking", was it a one time click, like a switch being engaged, or a constant, faint clicking sound, sort of like a mis-adjusted lifter? Under normal operation, since you have an electronic feedback Q-Jet, you should hear a faint clicking sound, as the mixture solenoid is "pulsing" the metering rods. If you don't hear that all the time, but did when you "jumpered" the ports, then you have an electronics issue, I would say....
When you say you heard a "clicking", was it a one time click, like a switch being engaged, or a constant, faint clicking sound, sort of like a mis-adjusted lifter? Under normal operation, since you have an electronic feedback Q-Jet, you should hear a faint clicking sound, as the mixture solenoid is "pulsing" the metering rods. If you don't hear that all the time, but did when you "jumpered" the ports, then you have an electronics issue, I would say....
When I jumped the ports last time, I heard a faint, fast clicking sound, apparently normal while jumping the ports. This time I did not hear anything.
When I jumped the ports last time, I heard a faint, fast clicking sound, apparently normal while jumping the ports. This time I did not hear anything.
If you can start the car, and it will idle, listen around the front of the carb. You should hear the faint clicking, at all times, while the engine is running.
In the front of the carb, there's the spot where the wires attach to it. This is an electrical solenoid, whose job it is, to control the "pulse" of the main metering rods, while they constantly adjust the fuel mixture, based on feedback from the O2 sensor.
Just for reference, next to this solenoid, in the middle of the air horn, there's a small "tower", with a round plug driven into it. Underneath this plug, is a screw that's used to adjust the travel of the main jets. That adjustment is made using a dwell meter, with the engine running. However, to access this adjusting screw, the plug has to be removed, which usually requires the removal of the air horn, so you can tap it out from the underside.
But this also requires that the feedback electrics are working properly. If you don't hear the constant pulsing of this solenoid, with the engine running, you have a deeper problem. The last time that I worked on one of these "electronic feedback" carbs, was around 1992-94, on a 1985 Firebird that I had back then, as well as a 1982 Buick, that was my "winter driver", also in that timeframe, so I'm going by memory of what I did to keep those cars running properly.
If you can start the car, and it will idle, listen around the front of the carb. You should hear the faint clicking, at all times, while the engine is running.
In the front of the carb, there's the spot where the wires attach to it. This is an electrical solenoid, whose job it is, to control the "pulse" of the main metering rods, while they constantly adjust the fuel mixture, based on feedback from the O2 sensor.
Just for reference, next to this solenoid, in the middle of the air horn, there's a small "tower", with a round plug driven into it. Underneath this plug, is a screw that's used to adjust the travel of the main jets. That adjustment is made using a dwell meter, with the engine running. However, to access this adjusting screw, the plug has to be removed, which usually requires the removal of the air horn, so you can tap it out from the underside.
But this also requires that the feedback electrics are working properly. If you don't hear the constant pulsing of this solenoid, with the engine running, you have a deeper problem. The last time that I worked on one of these "electronic feedback" carbs, was around 1992-94, on a 1985 Firebird that I had back then, as well as a 1982 Buick, that was my "winter driver", also in that timeframe, so I'm going by memory of what I did to keep those cars running properly.
Thanks Leadfoot, II have the battery disconnected right now to reset the computer. The car runs pretty well considering its 36 years old and prob never had a carb rebuild and everything is original. Im going to connect it back up in a few minutes and ill start her up and see if I can hear the MCS while running. I do however still have that "23" code when I jump the terminals.
I still have one of the older Sun/Acton plug in code readers (I'm a packrat, never discard anything!), and according to the book that comes with it, Code 23 is a "Manifold Air Temperature (MAT) Sensor" error, signal voltage is low. Also/or, if the car has a throttle position sensor (TPS), that could be faulty, which could also be a Code 23. However, I don't see a TPS in your pictures.
The book also defines the MAT as a thermistor whose resistance varies by temperature (I assume coolant temperature), and feeds back to the ECM, to determine fuel delivery calculations. (possibly the plug with the yellow and black leads, in the front RH of the engine, in your picture)
Code 23 is the mix control solenoid.
check it for continuity, (plug is top of carb front left, should be around 10ohm from memory) if ok, check for power on the pink wire, with ignition on.
09-22-2017, 04:27 PM
Intake/carb question on 81...
