Seriously Lean after Intake Swap (LT1)
Thread Starter
Member
Joined: Apr 2007
Posts: 113
Likes: 0
From: BC, Canada
Car: C4 Vette
Engine: Gas Guzzler
Transmission: ZF-6 Manual
Axle/Gears: 3.75
Seriously Lean after Intake Swap (LT1)
I've just done an LT1 Intake converison on a 85 Corvette and now i'm seeing a seriously lean BLM when logging. The car stumbles on load and mid-heavy throttle.
I've had an ignition problem which seemes to have been cured by replaceing the module in the camaro distributor. At least its not come back yet....
I'm seeing BLM's of 150-160 when loaded up, 128 on idle tickover. Fuel pressure has been adjusted up to nearly 50psi with very little change. I'm also showing 4-6deg of Knock on load.
I'm now stuck at the point at that I don't know if its an ignition problem causing the lean readings, or being so lean that its not stubbling.
Tomorrow I will try and get my Wideband installed to get a better idea of whats going on. I think i'll also burn a chip with LOTS more fuel to see if that makes a difference?
I've never read that people have had to do this much mapping just to get the car running right.
Any advice greatly appreciated!
Heres some history on the car, its a 1985...
Main:
1984 Block with Forged Pistons
1987 128 Alloy Heads
1994 LT1 Intake manifold converted for SBC Gen1 Heads
204/214 @.50 - Summit Cam
Ignition:
1987 Camaro Distributor and Coil Pack
1992 7730 Speed Density ECM
New Rotor
New Leads
Fuel:
1985 Fuel Pump
LT1 Fuel Rails
1992 TPI Fuel Injectors
Adjustable Fuel Pressure Regulator
I've had an ignition problem which seemes to have been cured by replaceing the module in the camaro distributor. At least its not come back yet....
I'm seeing BLM's of 150-160 when loaded up, 128 on idle tickover. Fuel pressure has been adjusted up to nearly 50psi with very little change. I'm also showing 4-6deg of Knock on load.
I'm now stuck at the point at that I don't know if its an ignition problem causing the lean readings, or being so lean that its not stubbling.
Tomorrow I will try and get my Wideband installed to get a better idea of whats going on. I think i'll also burn a chip with LOTS more fuel to see if that makes a difference?
I've never read that people have had to do this much mapping just to get the car running right.
Any advice greatly appreciated!
Heres some history on the car, its a 1985...
Main:
1984 Block with Forged Pistons
1987 128 Alloy Heads
1994 LT1 Intake manifold converted for SBC Gen1 Heads
204/214 @.50 - Summit Cam
Ignition:
1987 Camaro Distributor and Coil Pack
1992 7730 Speed Density ECM
New Rotor
New Leads
Fuel:
1985 Fuel Pump
LT1 Fuel Rails
1992 TPI Fuel Injectors
Adjustable Fuel Pressure Regulator
Joined: Sep 2005
Posts: 27,996
Likes: 2,485
Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: Seriously Lean after Intake Swap (LT1)
1992 TPI Fuel Injectors
Start there. Throw those Multecs in the trash. I'd suggest starting out with 24# injectors from the newer Frod cars & trucks, the little thin-body light blue ones (make sure they have the right connector); you can buy them all day long on eBay. These are the 4-hole Bosch units. This type here http://cgi.ebay.com/ebaymotors/24-LB...em180211930699
They are SO CHEEP if bought used, and so popular, that you've got nothing to lose even if they don't work right for you.
Last edited by sofakingdom; Feb 2, 2008 at 09:24 AM.
Joined: Jul 1999
Posts: 12,100
Likes: 127
From: SALEM, NH
Car: '88 Formula
Engine: LC9
Transmission: 4L60E
Axle/Gears: 3.89 9"
Re: Seriously Lean after Intake Swap (LT1)
It appears it was the map sensor from this post:
http://forums.corvetteforum.com/show....php?t=1929792
-- Joe
http://forums.corvetteforum.com/show....php?t=1929792
-- Joe
Thread
Thread Starter
Forum
Replies
Last Post
1992 Trans Am
Engine/Drivetrain/Suspension Parts for Sale
1
Aug 8, 2015 08:16 PM
