ZR-1 Net Registry Forums - View Single Post

bdw18_123 · 09-30-2011

Ok, please don't take this the wrong way guys, as I don't have any bad intent here, but judging by some the suggestions you are making, clearly my posts are not being read carefully enough.

First of all, 4 cats? Um, no, there are only 3 intact ones. The passenger side cat on my original passenger side exhaust manifold has NO substrate! It is just an empty can, totally empty, which is the whole reason why I put Cliff's cats on in the first place. So that manifold is useless. The driver side cat on my original driver side exhaust manifold is still totally intact, but has 140K miles on it. Using it instead of the one with only 50K doesn't make any sense.

Now the cats in the 50K exhaust manifolds from Cliff are both totally intact, I visually inspected them on both sides (thru the O2 sensor hole and thru the exhaust pipe where it connects to the rest of the exhaust system). I'm fairly sure the cats are not the issue here. Yes, I could have a bad O2 sensor, but I think that is not a very high possibility considering the type of failure and how it occurs.

Now on the fuel injectors, like I have already stated several times, they are not original. They are rebuilt Bosch II's that I got from Jon at FIC. Read my previous posts for the story on those.

As for the fuel pumps, still no one has answered this question: How can a bad fuel pump so consistently cause only the left side of the engine to be lean? It feeds both sides! It just doesn't make sense to me in this case that it would be the pumps.

Back to the original problem, I agree that it is most likely a fuel issue. We can forget about exhaust issues, I have Cliff's 50K manifolds on there, those aren't the issue.

I have a cable I made and a program that I can try to do live datalogging with on my laptop (I used it on the '93 LT1 Corvette I used to have), but I don't really know how to interpret the O2 readings, BLMs of the injectors, ect. I'll post it here when I get around to trying it, maybe one of you guys will know how to interpret it. If that doesn't work, I may need to borrow that Tech 1A of yours, Mike100. I'll have to see.

I think I may take a break from trying to figure out this problem and mess with it later. It is discouraging and I kind of don't want to deal with it right now...

09-30-2011	#17
bdw18_123 Join Date: Apr 2009 Location: Prather, CA Posts: 804	Re: 1990 exhaust manifold issue... Ok, please don't take this the wrong way guys, as I don't have any bad intent here, but judging by some the suggestions you are making, clearly my posts are not being read carefully enough. First of all, 4 cats? Um, no, there are only 3 intact ones. The passenger side cat on my original passenger side exhaust manifold has NO substrate! It is just an empty can, totally empty, which is the whole reason why I put Cliff's cats on in the first place. So that manifold is useless. The driver side cat on my original driver side exhaust manifold is still totally intact, but has 140K miles on it. Using it instead of the one with only 50K doesn't make any sense. Now the cats in the 50K exhaust manifolds from Cliff are both totally intact, I visually inspected them on both sides (thru the O2 sensor hole and thru the exhaust pipe where it connects to the rest of the exhaust system). I'm fairly sure the cats are not the issue here. Yes, I could have a bad O2 sensor, but I think that is not a very high possibility considering the type of failure and how it occurs. Now on the fuel injectors, like I have already stated several times, they are not original. They are rebuilt Bosch II's that I got from Jon at FIC. Read my previous posts for the story on those. As for the fuel pumps, still no one has answered this question: How can a bad fuel pump so consistently cause only the left side of the engine to be lean? It feeds both sides! It just doesn't make sense to me in this case that it would be the pumps. Back to the original problem, I agree that it is most likely a fuel issue. We can forget about exhaust issues, I have Cliff's 50K manifolds on there, those aren't the issue. I have a cable I made and a program that I can try to do live datalogging with on my laptop (I used it on the '93 LT1 Corvette I used to have), but I don't really know how to interpret the O2 readings, BLMs of the injectors, ect. I'll post it here when I get around to trying it, maybe one of you guys will know how to interpret it. If that doesn't work, I may need to borrow that Tech 1A of yours, Mike100. I'll have to see. I think I may take a break from trying to figure out this problem and mess with it later. It is discouraging and I kind of don't want to deal with it right now... Last edited by bdw18_123; 09-30-2011 at 09:01 PM.