I have an 89 lo3 powered 305 tbi rs, with the 700 r4. getting code 32, so im going to the junk yard to pull a whole system. I need to know the fitment (what other years, motors, cars, trucks will have the right egr set up)? forgot its an e code car. I just started driving this car every day. how much is it hurting it to keep driving it? Motor was just rebuilt.

 

It doesn't hurt the engine to drive it with no EGR. It hurts gas mileage a little, and it won't pass an emissions test, but that's it. The LO3 was used in '88-'92 Camaro, Firebird, Formula, Caprice, and Roadmaster cars. The pickup truck version is slightly different, but may serve.

 

OK that makes me feel better. I read the tech article on here. It said that when timing advances, & the egr valve gets the call to open in order to send the motor cooler air, that without, can cause detonation. Said the only way its keeping my motor from blowing up, is that the knock sensor retards the timing. Thought that was good info, so it freaked me out. That's why I didn't know if it was bad to drive it that way. Thanks.

 

If the computer gets a signal from the knock sensor, it pulls a few degrees, and you can feel it. It'll also trip the check engine light. Unless it's already on for the EGR. As you intend to fix the EGR, if the pulling timing gets too annoying, switch to 91+ octane until the EGR is working again. Pulling timing is how it saves the engine from damage.

 

k Thanks again. Wish the tank was empty. Just filled it. should have it fixed before it runs out.

 

Before you spend all the money on new parts, go over the existing setup first. Its possible you didnt hook up a wire or a vacuum line correctly with the new engine install, and that is what is setting the code.

 

Good idea. The guy before me had it rebuilt in a shop, but today that don't mean its right.

 

Ok guys I need more help on this. I bought a parts car. Same year with everything the same, except the parts car has t tops. When I looked at the vacuum lines coming off the EGR controllers they where not the same. Their are only two lines. One goes to the front of the TB, while the other goes to the EGR valve. On the parts car the hose closest to the TB was going to the TB. On my car it was going to the EGR. So I swaped them. No time to drive it 10 miles or more now. Was the parts car right, or was mine? Someone take a look on their car for me, please.

 

The EGR only has a solenoid that switches vacuum on/off when commanded by the ECM, there's isn't a separate controller. Look at the EGR valve part number on your motor, it should start with a P, or N for positive, or negative back pressure.
The EGR uses ported vacuum supplied by the TB. From the Solenoid One line goes to the EGR valve the other to the TB. The hood should have an emissions routing sticker on it. A search will get you a picture of it either here, or on the web.

 

What rgarcia said. There is an EGR soleniod in between the vacuum line from the TB and the vacuum line to the EGR valve that is run by the ECM (it has a 2-wire electrical connection that the ECM uses to cycle it). Gotta have that if you want it to run right. It functions exactly like rgarcia describes.

 

Ya that's what I was talking about. The lines where backwards on one of the cars. Must have been mine, cause I swapped them, & so far, so good.

 

What EGR type is for the LO3 TBI 305, negative or positive?

I have a positive on mine, but was looking up the ACDelco part number 17113496 here, and it looks like that one is a negative. I have a slight stumble at idle.