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CarburetorsCarb discussion and questions. Upgrading your Third Gen's carburetor, swapping TBI to carburetor, or TPI to carburetor? Need LG4 or H.O. info? Post it here.
Long time lurker, first time poster. I recently purchased the 1986 Z28 that my father bought brand new. The car is in really nice condition considering it has 300k on the clock! The motor is all original LG4 with T5 transmission. My brother has owned it for the past 20+ years and did a pretty good job of maintaining the car but he was not a mechanic so any work needed was sent out. I'm in the process of attempting to put the car back to original and getting it to run better. Currently the carb is my most pressing issue. He bought a reman Qjet for it in 2016 but it has never run right since installation. It's only had about 3k put on it since about 2009, just sitting in the garage. The serial number on the carb is 17085313. From what I can find on the web, it seems this may be for an automatic transmission if that matters. Presently I have a code 23 and the EGR valve has been removed and a block off plate has been installed. I don't hear the M/C solenoid clicking when I turn on the ignition and havent started tracing that down yet.
My question is, is this the right carb and will I need to get the EGR back functioning to get the car to run right. It is extremely rich and will not respond well if i try to go WOT.
Post a good clear close-up photo of the carb, and tell us the number stamped on the left side, kind of along a flange with a long screw going all the way down through it, just above the secondary throttle shaft. The number should look something like 17086201.
Post a good clear close-up photo of the carb, and tell us the number stamped on the left side, kind of along a flange with a long screw going all the way down through it, just above the secondary throttle shaft. The number should look something like 17086201.
OK den, that's for a 85 auto car. Probably missing a bit or 2, maybe even with acoupla extra little bits. Butt hay, we can work on that.
Get a photo somewhat somewhere more nearly like about this.
Maybe a shade farther away so we can see the rest of the wiring and sensors and whatnot all around the scene of the crime. But close enough to see all of the connectors to the carb and what's plugged into them, and its vacuum lines, and stuff like that. Let's see what we're working with.
OK den, that's for a 85 auto car. Probably missing a bit or 2, maybe even with acoupla extra little bits. Butt hay, we can work on that.
Get a photo somewhat somewhere more nearly like about this.
Maybe a shade farther away so we can see the rest of the wiring and sensors and whatnot all around the scene of the crime. But close enough to see all of the connectors to the carb and what's plugged into them, and its vacuum lines, and stuff like that. Let's see what we're working with.
IAB is center of the little tower, about 1inch wide, directly in front of the choke plate. will have a slot for a flat blade
screw it down first counting turns, expect it to be about 4 turns out
.
remove it and inspect the little plunger on the end, it should go in and out with a spring that provides enough pressure to keep it out
then you can insert a small rod into the opening and try to bounce the MCS up and down. if it's stuck you won't feel anything move.
Update:
I've determined that the M/C is not functioning and ordered a NOS. I'm also going to order a rebuild kit. I know the carb is not correct per the part number so should I order a rebuild kit for the correct part number or go with the number on the carb?
Update Update: after complete rebuild the vast runs 💯 better. The M/C was stuck and non operational causing the rich mixture. Now on to fine tuning. Thanks for the help.
09-28-2023, 09:03 PM
