LG4 mods and questions
LG4 mods and questions
why are there millions of vacuum lines across the intake and around the engine of my LG4? can they be removed if i switch to a non computer controlled carb set up?
so far these are the parts i have gathered:
edelbrock performer 600
edelbrock aluminum intake
ac delco vacuum advance dist
stuff i want/ still have to get:
transmission wiring thingy
what parts am i missing to finish off the swap? this cc q-jet set up is breaking my ***** here. i would also like to get a msd ignition box, msd blaster, and msd dist in the future.
so far these are the parts i have gathered:
edelbrock performer 600
edelbrock aluminum intake
ac delco vacuum advance dist
stuff i want/ still have to get:
transmission wiring thingy
what parts am i missing to finish off the swap? this cc q-jet set up is breaking my ***** here. i would also like to get a msd ignition box, msd blaster, and msd dist in the future.
Senior Member
Joined: Nov 2006
Posts: 455
Likes: 0
Car: 1984 Trans Am
Engine: Built chevy 350
Transmission: TCI Built 700r4
Axle/Gears: 3.73 posi 10 bolt
Re: LG4 mods and questions
Some of them vacuum lines you will still need, there is one for your heater I think it controls the blend door or something and I am sure there is one for your transmission...those are two that I can think of right at the moment and there may be a few more you need.
Joined: Mar 2000
Posts: 43,187
Likes: 45
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
There isn't any vacuum line to a TH700R-4 transmission.
Keep the intake (assuming it's a Performer intake - you weren't specific), return the rest. Unless you enjoy expense and disappointment.
The CC q-jet is a much better choice for performance, economy, and flexibility. The Performer is based on 50-year-old technology, and although it "works", these pages are filled with the frustrations caused by them. Yes, people have "issues" with the CC q-jet as well, but it's typically because of something they're overlooking, or simple refusal to understand how the system works and what you need to provide it.
There aren't "millions of vacuum lines" running across the engine. The uses are simple and logical. Could it be cleaner? Yes. Moving the purge control valve over closer to the canister would be one way. But, it really isn't that bad, and the vacuum diagram under the hood explains it all. If you go with headers (a much better return on your performance $'s), you can eliminate the EFE and its associated tubing - that's a good start on the clean-up.
I simply do not understand why anyone would take off a perfectly good system and put on something that will cost money to install, defeat useful purposes that will cost more money to restore, perform no better and will perform worse if true upgrades are made, cause damage if certain provisions aren't made, and will cost more to operate.
It makes absolutely no sense at all.
Something that should always be included with this modification is a lobotomy.
Keep the intake (assuming it's a Performer intake - you weren't specific), return the rest. Unless you enjoy expense and disappointment.
The CC q-jet is a much better choice for performance, economy, and flexibility. The Performer is based on 50-year-old technology, and although it "works", these pages are filled with the frustrations caused by them. Yes, people have "issues" with the CC q-jet as well, but it's typically because of something they're overlooking, or simple refusal to understand how the system works and what you need to provide it.
There aren't "millions of vacuum lines" running across the engine. The uses are simple and logical. Could it be cleaner? Yes. Moving the purge control valve over closer to the canister would be one way. But, it really isn't that bad, and the vacuum diagram under the hood explains it all. If you go with headers (a much better return on your performance $'s), you can eliminate the EFE and its associated tubing - that's a good start on the clean-up.
I simply do not understand why anyone would take off a perfectly good system and put on something that will cost money to install, defeat useful purposes that will cost more money to restore, perform no better and will perform worse if true upgrades are made, cause damage if certain provisions aren't made, and will cost more to operate.
It makes absolutely no sense at all.
Something that should always be included with this modification is a lobotomy.
Joined: Aug 1999
Posts: 19,282
Likes: 103
From: Lawrence, KS
Car: Met. Silver 85 IROC/Sold
Engine: 350 HO Deluxe (350ci/330hp)
Transmission: T-5 (Non-WC)
Axle/Gears: Limited Slip 3.23's
Member
Joined: Nov 2001
Posts: 315
Likes: 0
From: Huber Heights (DAYTON), Ohio U.S.
Car: 83 T/A WS-6
Engine: LG4 305
Transmission: T-5 Manual Clutch
Axle/Gears: 3.73 Positraction
Re: LG4 mods and questions
I removed almost all my vacuum lines and still run the CCC Q-Jet and the car runs flawless. I made a plate to eliminate the EGR valve and a couple more things. I still get about 26 mpg and the carb performs great. Love to hear that 4 barrel howl.
Senior Member
iTrader: (5)
Joined: Mar 2007
Posts: 898
Likes: 0
From: Texas
Car: 1987 Camaro
Engine: 5.7
Transmission: 700R4
Re: LG4 mods and questions
26 mpg? how are you doing that?
Member
Joined: Nov 2001
Posts: 315
Likes: 0
From: Huber Heights (DAYTON), Ohio U.S.
Car: 83 T/A WS-6
Engine: LG4 305
Transmission: T-5 Manual Clutch
Axle/Gears: 3.73 Positraction
Re: LG4 mods and questions
It runs just fine with no codes. I have checked the computer and it is running with no problems.
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Joined: Mar 2000
Posts: 43,187
Likes: 45
From: Littleton, CO USA
Car: 82 Berlinetta/57 Bel Air
Engine: L92/LQ4 (both w/4" stroke)
Transmission: 4L80E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Joined: Dec 2004
Posts: 1,132
Likes: 24
From: Midwest
Car: '82 Recaro T/A, '71 Trans Am
Engine: 305CFI/455HO
Transmission: TH700R4/M22
Axle/Gears: 3.23/3.42
Re: LG4 mods and questions
I'm getting 23 MPG with my '84 T/A LG4 with a 3.23 ratio rear end and the original O2 sensor. The car still smells a little rich so I think it could do a little better with a new sensor.
I bet a LG4 in a base model car with an OD trans and 2-series ratio rear end could get pretty close to 30MPG on the highway.
I bet a LG4 in a base model car with an OD trans and 2-series ratio rear end could get pretty close to 30MPG on the highway.
Senior Member
iTrader: (4)
Joined: Feb 2003
Posts: 872
Likes: 1
From: Weedsport, NY
Car: 1986 Camaro SC
Engine: Bolt-on/cam 305
Transmission: 700R4 w/ 2500stall
Axle/Gears: 3.73 10bolt Posi
Re: LG4 mods and questions
I'm getting 23 MPG with my '84 T/A LG4 with a 3.23 ratio rear end and the original O2 sensor. The car still smells a little rich so I think it could do a little better with a new sensor.
I bet a LG4 in a base model car with an OD trans and 2-series ratio rear end could get pretty close to 30MPG on the highway.
I bet a LG4 in a base model car with an OD trans and 2-series ratio rear end could get pretty close to 30MPG on the highway.
Senior Member
iTrader: (5)
Joined: Mar 2007
Posts: 898
Likes: 0
From: Texas
Car: 1987 Camaro
Engine: 5.7
Transmission: 700R4
Re: LG4 mods and questions
maybe I need to get rid of this bosch sensor and try a factory one, because I have the auto and 2.73's and I dont get that
Last edited by KYLE87; Jan 23, 2008 at 04:16 PM.
Member
Joined: Nov 2001
Posts: 315
Likes: 0
From: Huber Heights (DAYTON), Ohio U.S.
Car: 83 T/A WS-6
Engine: LG4 305
Transmission: T-5 Manual Clutch
Axle/Gears: 3.73 Positraction
Re: LG4 mods and questions
I do have a 5-speed. The car doesn't have headers but it don't have catalytic converter and does have a 2 1/2" flowmaster muffler. I can cruise forever in that car on a tank of gas. I don't have any power robbing belts except the power steering and water pump belts.
On these older 3rd gens spark plug, wires and a basic tuneup with fuel filter, pcv valve make a difference on these cars. I change my spark plugs every 6,000 miles whether it needs them or not. I haven't put more than 16,000 miles on the car and I have changed plugs 3 times and plug wires a couple times, a couple distributor caps and rotor buttons. All that stuff makes a big difference on the carbed cars. I never change any of that stuff on my newer cars.
On these older 3rd gens spark plug, wires and a basic tuneup with fuel filter, pcv valve make a difference on these cars. I change my spark plugs every 6,000 miles whether it needs them or not. I haven't put more than 16,000 miles on the car and I have changed plugs 3 times and plug wires a couple times, a couple distributor caps and rotor buttons. All that stuff makes a big difference on the carbed cars. I never change any of that stuff on my newer cars.
Senior Member
iTrader: (5)
Joined: Mar 2007
Posts: 898
Likes: 0
From: Texas
Car: 1987 Camaro
Engine: 5.7
Transmission: 700R4
Re: LG4 mods and questions
Yeah I am an automatic so that probally doesnt help much, but I have headers to 3in straight to flowmaster dual outlet muffler, no cat here either...i could probally could use a tune up, Im on a new ccc q-jet and fresh tune on it. Im gonna try and have the plug wires and spark plugs changed. What kind do you use?? Also what should I use for the cap and rotor, these havent been changed in a while and do a stock oxygen sensor instead of this bosch one.
Im also trying to get ahold of a l69 chip
Im also trying to get ahold of a l69 chip
Junior Member
Joined: Aug 2007
Posts: 53
Likes: 0
From: Gulfport, Florida
Car: Toyota Slowica
Engine: 2.2 liters of raw muscle
Transmission: 5 speed stick
Re: LG4 mods and questions
your lucky, my 1990 celica runs around 4000rpms at 75mph... I am lucky to get 20 MPG if I travel above 70MPH...
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