I run pretty rich.
Thread Starter
TECH Apprentice
Joined: Oct 2004
Posts: 329
Likes: 1
From: Tomball, TX (home) Kaneohe Bay, HI (work)
I run pretty rich. Unique problem. This will probably just end up being that the computer needs tuned or something like that but this is my first fuel injected vehicle, so bear with me. 
In my Z, the original owner had a 396 in it. Everything was tuned to run the 396 on the strip and I think he said it ran 10s or 11s, or something. Anyway, before selling it they put in an LT1. Currently it only has 14K miles on. The problem is when I am sitting at idle, the fuel mixture is so rich, that I can smell un burned fuel inside and outside the car. I am thinking that the computer is still tuned for that 396 and perhaps they left that out while putting in the LT1.
I am just trying to figure out the best way to fix this. When I am on the highway and want to pass someone, if I give it gas, it just sputters and doesn't accelerate very well. Perhaps the injectors are too fat for the smaller motor...? Anyway, any help is appreciated. I couldn't really search because I didn't think there were many folks here who downsized from a 396 to an LT1.
By the way, 1994 Z28. 6-speed...in case that stuff matters.
In my Z, the original owner had a 396 in it. Everything was tuned to run the 396 on the strip and I think he said it ran 10s or 11s, or something. Anyway, before selling it they put in an LT1. Currently it only has 14K miles on. The problem is when I am sitting at idle, the fuel mixture is so rich, that I can smell un burned fuel inside and outside the car. I am thinking that the computer is still tuned for that 396 and perhaps they left that out while putting in the LT1.
I am just trying to figure out the best way to fix this. When I am on the highway and want to pass someone, if I give it gas, it just sputters and doesn't accelerate very well. Perhaps the injectors are too fat for the smaller motor...? Anyway, any help is appreciated. I couldn't really search because I didn't think there were many folks here who downsized from a 396 to an LT1.
By the way, 1994 Z28. 6-speed...in case that stuff matters.
On The Tree
Joined: Jan 2003
Posts: 159
Likes: 0
From: Lafayette , Indiana
Originally Posted by djfuzzy
Unique problem. This will probably just end up being that the computer needs tuned or something like that but this is my first fuel injected vehicle, so bear with me.
In my Z, the original owner had a 396 in it. Everything was tuned to run the 396 on the strip and I think he said it ran 10s or 11s, or something. Anyway, before selling it they put in an LT1. Currently it only has 14K miles on. The problem is when I am sitting at idle, the fuel mixture is so rich, that I can smell un burned fuel inside and outside the car. I am thinking that the computer is still tuned for that 396 and perhaps they left that out while putting in the LT1.
I am just trying to figure out the best way to fix this. When I am on the highway and want to pass someone, if I give it gas, it just sputters and doesn't accelerate very well. Perhaps the injectors are too fat for the smaller motor...? Anyway, any help is appreciated. I couldn't really search because I didn't think there were many folks here who downsized from a 396 to an LT1.
By the way, 1994 Z28. 6-speed...in case that stuff matters.
In my Z, the original owner had a 396 in it. Everything was tuned to run the 396 on the strip and I think he said it ran 10s or 11s, or something. Anyway, before selling it they put in an LT1. Currently it only has 14K miles on. The problem is when I am sitting at idle, the fuel mixture is so rich, that I can smell un burned fuel inside and outside the car. I am thinking that the computer is still tuned for that 396 and perhaps they left that out while putting in the LT1.
I am just trying to figure out the best way to fix this. When I am on the highway and want to pass someone, if I give it gas, it just sputters and doesn't accelerate very well. Perhaps the injectors are too fat for the smaller motor...? Anyway, any help is appreciated. I couldn't really search because I didn't think there were many folks here who downsized from a 396 to an LT1.
By the way, 1994 Z28. 6-speed...in case that stuff matters.
TECH Senior Member
Joined: Apr 2004
Posts: 6,157
Likes: 1
From: Texas
I would find someones stock tune and load that on there if it was mine. Do you have cats on there? If you dont you cannot smell if the car is running rich or lean. Both conditions smell the same with no cats.
Thread Starter
TECH Apprentice
Joined: Oct 2004
Posts: 329
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From: Tomball, TX (home) Kaneohe Bay, HI (work)
I think it is running rich because when I gun it at highway speeds to accelerate it bogs down a little bit. Like it is getting too much gas in there.
TECH Senior Member
Joined: Apr 2004
Posts: 6,157
Likes: 1
From: Texas
Well that could be alot of things. One way to tell is get it going on the highway and then let off the gas. Does it pop? Poping is the buring off of unburnt fuel in the exaust. You can also take your plugs out and look at them. Of course wideband will be the best and only really accurate way to tell A/F ratio. 
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TECH Senior Member
Joined: Apr 2004
Posts: 6,157
Likes: 1
From: Texas
Originally Posted by WhiteSSP
Yeah my car is running rich as hell too, even after a MadZ28 tune 
I get 12mpg mixed, and 17mpg highway, all with a tiny cam (218/224, ~.500 lift, 112LSA).
I get 12mpg mixed, and 17mpg highway, all with a tiny cam (218/224, ~.500 lift, 112LSA).That is pretty bad, I get 15 in town with back to back red lights and traffic in my stalled trex
Launching!
Joined: Sep 2004
Posts: 265
Likes: 1
From: Norfolk, VA
Originally Posted by 2MuchRiceMakesMeSick
That is pretty bad, I get 15 in town with back to back red lights and traffic in my stalled trex
Thread Starter
TECH Apprentice
Joined: Oct 2004
Posts: 329
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From: Tomball, TX (home) Kaneohe Bay, HI (work)
2MuchRiceMakesMeSick, it does pop when I let off the gas at highway speed. I called Chuck from HPE down here in Houston and he said the computer tune will do the trick and get it to run better than with the 396 tune. All that is left to do is get the 400 bucks for the tune and I will be running great!
And WhiteSSP, mine is the same way. When I let my car run in the morning before I head off so it is at a good temp, it wreaks of fuel in there. Makes my eyes water. Good thing my windows work!
And WhiteSSP, mine is the same way. When I let my car run in the morning before I head off so it is at a good temp, it wreaks of fuel in there. Makes my eyes water. Good thing my windows work!
TECH Senior Member
Joined: Apr 2004
Posts: 6,157
Likes: 1
From: Texas
Originally Posted by djfuzzy
2MuchRiceMakesMeSick, it does pop when I let off the gas at highway speed. I called Chuck from HPE down here in Houston and he said the computer tune will do the trick and get it to run better than with the 396 tune. All that is left to do is get the 400 bucks for the tune and I will be running great!
And WhiteSSP, mine is the same way. When I let my car run in the morning before I head off so it is at a good temp, it wreaks of fuel in there. Makes my eyes water. Good thing my windows work!
And WhiteSSP, mine is the same way. When I let my car run in the morning before I head off so it is at a good temp, it wreaks of fuel in there. Makes my eyes water. Good thing my windows work!
Thread Starter
TECH Apprentice
Joined: Oct 2004
Posts: 329
Likes: 1
From: Tomball, TX (home) Kaneohe Bay, HI (work)
I emailed Ion to ask him about his stuff and have not recieved a reply yet...is MadZ28 a good way to go? Are there other places I can get a stock tune program loaded up?
PCM Tuning
Originally Posted by djfuzzy
Unique problem. This will probably just end up being that the computer needs tuned or something like that but this is my first fuel injected vehicle, so bear with me.
In my Z, the original owner had a 396 in it. Everything was tuned to run the 396 on the strip and I think he said it ran 10s or 11s, or something. Anyway, before selling it they put in an LT1. Currently it only has 14K miles on. The problem is when I am sitting at idle, the fuel mixture is so rich, that I can smell un burned fuel inside and outside the car. I am thinking that the computer is still tuned for that 396 and perhaps they left that out while putting in the LT1.
I am just trying to figure out the best way to fix this. When I am on the highway and want to pass someone, if I give it gas, it just sputters and doesn't accelerate very well. Perhaps the injectors are too fat for the smaller motor...? Anyway, any help is appreciated. I couldn't really search because I didn't think there were many folks here who downsized from a 396 to an LT1.
By the way, 1994 Z28. 6-speed...in case that stuff matters.
In my Z, the original owner had a 396 in it. Everything was tuned to run the 396 on the strip and I think he said it ran 10s or 11s, or something. Anyway, before selling it they put in an LT1. Currently it only has 14K miles on. The problem is when I am sitting at idle, the fuel mixture is so rich, that I can smell un burned fuel inside and outside the car. I am thinking that the computer is still tuned for that 396 and perhaps they left that out while putting in the LT1.
I am just trying to figure out the best way to fix this. When I am on the highway and want to pass someone, if I give it gas, it just sputters and doesn't accelerate very well. Perhaps the injectors are too fat for the smaller motor...? Anyway, any help is appreciated. I couldn't really search because I didn't think there were many folks here who downsized from a 396 to an LT1.
By the way, 1994 Z28. 6-speed...in case that stuff matters.