I removed the egr system and air pump, blocked everything off and now the car just keeps popping as if it's lean, does the car need a tune? It's a 93 z28 6 speed with headers exhaust, speed density. No lights on the dash though. Any help would be great. Thanks

 

I’m not sure if the ‘93 is different than later years of the fbody with its computer, but 94+ definitely have items to tune out. That said, the tune out should not impact how the car runs, just the SES light.

If you are getting popping and this is the only change, I’d be willing to bet you have an exhaust leak from one or more spots. I’d start with the check valve ports on both manifolds and the passenger side port that was connected to the egr port on the manifold.

 

I will take a better look tomorrow and make sure I didn't miss anything. Thank you for replying

 

Let us know what you find and good luck!

 

Maybe try the firebirdnation.com web site. There are some 93 F-body owners there.

 

So an update, I did figure out that I had switched ignition wire 1 and 3, lol rookie mistake, and cleaned up all exhaust leaks car runs great but shuts off from time to time even in mid throttle, i changed both battery cables because the positive one was corroded, and negative since I was there, when it shuts off I still power and can crank till the sun goes down. Then if I let it sit for a minute then Fire it up and gently get it home. Any ideas? And thank you for the help earlier I had quite a few leaks.

 

Did you check for codes? An overheating ICM can cause the engine to shut down. Wouldn’t restart until the ICM cooled down. Typical codes would be DTC 41 or DTC 42.

 

The 93 AIR and EGR systems work the same as later years. Just the plumbing is different. Both AIR and EGR flow through a single pipe system that runs from the AIR pump to the passenger side manifold. When AIR is operating, EGR is not used. When EGR is operating, the AIR pump is not running.

http://shbox.com/1/1993_air_egr.jpg

AIR only runs during startup to reduce the hydrocarbon emission during rich cold start, and help the cat heat up. Then it shuts off, not used again until next engine start. Nothing to change in the program. As long as there is a good fuse in the AIR pump relay, the PCM is happy.

EGR is a bit more complicated. But the system used to verify EGR flow when flow is commanded is not real reliable. The EGR valve opens and the ECM looks for a change in MAP. Many people with OBD-1 cars have deleted EGR without getting a code. There may be a minor change in engine fueling when EGR is active, because the EGR in effect reduces the amount of air that can be pulled into the cylinders. In an MAF setup, the change in air flow would be reflected by the MAF reading, and the normal fuel calculation would result in reduced fuel flow. I don’t know how the reduced air flow would show up in the 93 speed-density system. If the presence of a volume of exhaust gas in the cylinder changed MAP by increasing it, would think speed-density would pick it up. Wouldn’t need to be a change in the tune.

Note that by deleting EGR you are increasing the chance of detonation (knock) when lugging the engine at low RPM, in the wrong gear, trying to accelerate up a steep hill, etc. Just means the knock sensor will be more active, and NOx emissions will increase. EGR is there to control NOx.

The key is eliminating leaks in the system.

 

OK I will look into this thank you for your help.