I just did a tune up on my 91 tbi firebird and also removed a bunch of crap under the hood. I started the car and it idled very rough and had a loud hissing from under the hood. Before I can get up there to check it out it stalls.

I'm assuming this is an egr problem. I just unhooked the vaccum hoses from it and capped the pressure source on the manifold. What side effects would I see with the egr disabled without rechipping the computer? Since I'm sure the egr valve is my vaccum leak right now I was just going to make a block off plate to put there. What problems would I have?


Also, sort of unrelated to the egr I also removed my air system for the most part. The lines coming out of the exhaust manifolds are still there because I didn't have the proper flare wrench to unbolt those so I just left those on until that plastic fitting or whatever you want to call it on both sides. I'm assuming there's an exhaust leak out of those or is there a check valve inside there?

 

I would like to know if there is a check valve in there as well. What I did to block those off was I took a small wooden cap, like you would use to cover a screw hole on a wood project, and I put a little silicone sealant around it and stuck it on and painted ti black, they have been on for years and havent fallen off.

 

It sounds like you have exhaust and vacuum leaks. You need to remove the EGR valve and use a block off plate. Cap the vacuum port on the TBI unit as well. However, that is merely a band air removal of the EGR. You need to change its operating parameters in the chip to truly delete it. Any reason why you deleted it? EGR is actually a good thing.

As for the exhaust there is no check valve in the f-body manifolds. You are venting exhaust out of the main AIR line. You can just cap that instead of each individual port.

 

I have my egr programmed out on my chip

 

Thanks for the info guys! I will make a block off plate tomorrow and delete the rest of the air lines and plug the manifolds. It turns out my dumbass forgot the vaccum line going to the map sensor and that's why it ran so rough. Once I plugged that back in it got a lot better but there is still a vaccum leak at the egr I'm assuming. Perhaps its partially open, but the block off plate will take care of that. Thanks for the quick responses.

Also, in regards to deleting the egr from the computer altogether, can't I just put a resistor of some sort inline with the 2 wires going to the plug for it to make the computer think it should keep it closed? If so what size resistor would I need? This seems like the cheapest / quickest way to "properly" delete it imo. Thoughts?