SDZ28

Hey guys, I tried doing some searches and didn't see any other topics on this issue.. it's kind of a complicated problem so I wasn't sure which forum to post this in. I'm having a problem with the carb flooding the engine, and I'm not sure if it's an electrical or vacuum issue or what, but I have a feeling its involved with the AIR system. I switched my stock manifolds out earlier this summer and replaced them with some hooker headers, and I wasn't sure what to do with all the AIR pipes that used to go into the manifolds, so I removed them and plugged the vacuum hoses that led to them. The car worked fine afterwords, I even took it on a 1000 mile trip with no issues. Around the end of the summer, I decided to take out the rest of the AIR system because it didnt seem to be leading to anything and was just cluttering up the engine bay. I took off the air pump and the hoses coming out of it, as well as the thing right above it that mounted on the front passenger corner of the engine. I attached a picture of it. Soon after doing this, the car started acting really goofy - when the engine is cold, it runs excellent, but after about 10-15 minutes of driving its hardly drivable. It acts like its flooding or theres a vacuum leak or something, I have looked and don't see any unplugged vacuum lines. I'm wondering if there's some kind of sensor in the thing I removed or if a vacuum that comes off it is supposed to give some kind of reading to the computer. I'll have a chance to work on it this weekend, I'm just wondering if I need to put the air pump and all that crap back on or if theres an easier way to solve this. Does everyone that puts headers in leave the AIR system intact? I know you're not supposed to mess with the AIR system, but I wasn't sure how to modify it to work with headers. This is an 82 carbed Z28. Thanks

Atilla the Fun

The correct approach before you did all this was to choose headers with AIR fittings, from Edelbrock, MAC, Hooker, Hedman and others. Even now, either Hooker or Hedman makes a kit to add AIR fittings to any SBC headers. But you can get your car to drive nicely without reinstalling the AIR. It would be federally illegal, but it is possible.

Rolling Thunder

I dont believe this is where your problem lies. Many people dissconnect there air systems and they run ok. There are 2 points the air system pumps air in the cat and the manifolds. When its pumped into the cat is has no effect on anything but emissions. However when the air pump is pumping air into the exhaust manifold this makes the O2 sensor read lean because again theres extra fresh air being pumped into the exhaust by the air pump. To account for this the the ECM knows and expects that the O2 sensor will be reading a little leaner that it actually is when the air diverted valve is set so that its pumping air into the exhaust manifold. What this means is because the EMC tries to keep a certant AF ratio (by monitoring the voltage at the O2 sensor) i knows when the air system is pumping air into the manifolds the reading will read a little lean and that if the air system is not working no fresh air is being pumped into the manifolds and the O2 sensor is reading normally when the ECM is expecting a slightly leaner reading. The ECM will see this as the cars running rich and then compensate for this by leaning the mixture out to make the O2 sensor read what its expecting for a value considering it thinks the air system is working (which its not). This means that the car will run lean when the ECM is calling for air to be pumped into the manifolds. So if anything the lack of an air system will make you run lean not rich. I think your problem lays else where.

SDZ28

Thanks for the info, I didn't realize some headers had the AIR fittings, I just looked for headers that said they were compatible with an 82 camaro, and when I saw they didn't have fittings I assumed the AIR system must not be important to the engine functioning. And Rolling Thunder, your point makes a lot of sense.. my problem must be from somewhere else because it is definitely flooding. I re-installed the AIR system anyway (just in case) all the way until it is supposed to go into the manifolds, and found a vacuum diagram on the forums here and made sure my hoses were all hooked up right, as I was doing this a bunch of gas poured out of the vacuum lines. I made a couple of short trips after this (10 miles or so) and the car ran fine, but on the third time I took it out it started doing its flooding thing again. The check engine light comes on about every time while I'm driving it, but when checking error codes nothing ever shows up, it just gives me the 'all-clear' code. When idling, the idle speed will jump from 700ish to 2500ish sometimes for no apparent reason.. sometimes it stays low, sometimes it stays high but its very random about it. Could there maybe be something wrong with my computer?

DemonYusuke

Im assuming the car was originally fuel injected, and it was switched to a carb?

SDZ28

It's been a carb since I've had it, I guess it could have been converted earlier but the VIN indicates that it came with an LG4 and I think those were all carb from the factory.

Zwrench

Does it still have the Quadrajet carb? If so, I think your problem may be a sticking float. As far as your intermittent high idle, check your throttle plates for sticking, particularly the secondaries. It might just be time for a carburetor overhaul.

Since the AIR system has no effect on fuel mixture, it's probably just a coincidence that you're flooding now.

Rolling Thunder

Gas should never be pouring out of the vacuum lines the should be dry except for maybe the PVC line and even that should be like oil if anything not gas. It sounds like your carb needs alittle attention probably a good time for a rebuild.