I just replaced my motor in my car and in the process i took off all the smog. including capping off the vacuum hoses also. i have a 1995 lt1. the car seems to be pulling timing, and not idleing well at all. i have checked everything i can think of but i am wondering when you pull that whole unit off. does the computer like it? i thought it only ran in open loop. I know alot of people have taken this off without a problem but am i missing something. the major problem i am seeing is that it is running really lean when my MAF is hooked up and really rich when the MAF is not hooked up. Not to mention it running like crap the whole time. in closed loop when u first start the car it runs great. Thought it might have something to do with my problem. please help

 

Your computer is going to throw codes when you remove smog equipment. A lot of the smog equipment doesn't hurt your performance at all and is best left in place. You need to scan your car's computer and determine what codes are being logged and fix them. What smog equipment did you pull off?

 

You might need to be specific on what you did and what year your car is.

The engine is in open loop when first started and then goes into closed loop later when it is warmed up. Don't know how you are telling about pulled timing and rich and lean without some scan data.

 

did u check your EGR valve. Surprising enough I had my buddies 96 Z. and she just stalled out on me when cruising and wouldnt idle for the life of her. Managed to get it home and i checked the EGR and the damn just fell off causing a massive vacum leak. Jus bolted back on and things were good.


later,
-john

 

Ok well i do have a scan tool. actually my friends computer program, tunercats or something. but that is how i know it is running rich. i assme it is pulling the timing due to the way it is running and how it starts. I took off the air pump, and all the hosing. capped off the manifolds. also took all the vacuum off. There have been some codes pull up but they were ignition module codes and i replaced that and it didnt help my problem.

OH checked EGR. Its all good. Never thought of that though thanks for the idea.

 

I have Datamaster that we have been logging data with. The airpump hasn't thrown any codes and we did everything correctly to eliminate it.

The car is a 95 and it runs pretty rough in both open and closed loop, worse in closed though naturally since the BLM's seem to be locked at 128 in open loop.

 

all i know is that i blocked the egr valve off... removed all the air pump parts blocked off the manifold pipes gutted the cat and had no codes, and still ran good, actually better got rid of my stumbling and hesitation..

jason