I have been gradually working on my car over the last couple of months. I bought it not running and had been sitting for around 3 years. The first thing i did was change all the fluids, and put plugs and wires on it. I then replaced the temperature sensors because they were giving false readings. The cat was stopped up, which was causing it to not run for over 15 minutes, so I had that replaced. The thing was running extremely rich so I changed my oxygen sensors, which didn't do anything. I noticed a slight exhaust leak so I pulled the manifolds and installed a set of headers, turns out the gaskets were blown. After this it ran better but I noticed that it still had a whistling under the hood. The air intake elbow was cut at the bottom so now I have an air intake coming in this week. My problem now is that the car is still running rough. Just curious if the air intake would cause the car to run extremely rich?(I would think it would but I don't know a lot about it) Also thought I'd check the injectors, what is a common resistance on stock injectors? I have already checked the fuel pressure and it is around 44lbs if I recall correctly. If anyone has any other ideas they would be greatly appreciated.

 

The intake being cut will definitely cause it to run rich. Your fuel pressure is a little off.You need to pull the vacuum line off the regulator and plug it to test the pressure. I cant recall the #s off hand right now. Do a search and you will find it. Someone else may chime in. Its should be about 47?

 

The intake being cut, AFTER the MAF sensor causes it to run lean. The PCM fuels the engine based on the lesser flow through the MAF. The O2 sensors "see" the excess air, and the PCM adds extra fuel using the long term fuel corrections, to bring it back to spec.

The problem is the slit in the intake is going to be a "variable" opening, opening and closing as the engine moves on the mounts, or as intake flow changes. That makes it hard for the PCM to make the corrections.

The spec for the fuel pressure, at idle, with the vacuum line disconnected is 43.5psi, with GM specs accepting anything in the range of 41-47psi. When the vacuum line is reattached, the pressure should drop proportional to intake manifold vacuum, or about a 6 to 8psi drop with a stock cam.

Have you have the injectors cleaned, after it sat dormant for 3 years?

 

Just what I said I have done was it. I ran fuel injector cleaner through 2 tanks of gas but that has been all.