LG4 problems.
#1
Junior Member
Thread Starter
Join Date: Mar 2012
Location: Las Vegas
Posts: 98
Likes: 0
Received 0 Likes
on
0 Posts
Car: 87 Camaro Lt
Engine: 350
Transmission: 700R4
Axle/Gears: 4th gen 3:42, posi, disc
LG4 problems.
I Just picked up my very first Camaro! It's an 87 lt with a bone stock LG4 and carb. I was told that the Motor and carb was rebuilt just over 15k miles ago(no papers to prove this). Now since I have never owned a Carbureted car and know nothing about carburetors I'm looking to you guys for help. For the most part the car runs and drives with no problems as long as im easy on the gas. 1) When I start my car after the motor is warmed up to about 205* it starts to bog down, and if I don't push and hold the gas pedal for about 3 seconds it stalls and then takes a second to start. After that three seconds it runs and idles fine. 2) My second problem also occurs when the car is warmed up. If I gun it from a dead stop it runs hard till about half way through second gear and then starts to bog and hesitate so I have to left off the gas and just let it idle for a few seconds before it stops.
So is this a carburetor problem? Is my problem fuel or air? Thank you for your time.
So is this a carburetor problem? Is my problem fuel or air? Thank you for your time.
#2
Moderator
Join Date: Jan 2000
Location: Mercedes Norte, Heredia, Costa Rica
Posts: 20,981
Likes: 0
Received 9 Likes
on
8 Posts
Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
Re: LG4 problems.
For problem #1, you mean the car runs badly for about 3 seconds after a hot start?
Problem #2 is a fuel delivery issue.
Problem #2 is a fuel delivery issue.
#3
Junior Member
Join Date: Mar 2010
Location: Titusville, Fl
Posts: 70
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1984 Trans Am
Engine: 350
Transmission: JW Performance 700R4
Axle/Gears: Borg Warner 9-bolt, 3.08 gears
Re: LG4 problems.
Sounds like the carb needs to be properly tuned. The stalling out when starting is probably due to the fast idle, idle mixture and choke not being set right. As for the second problem, usually this is because too much fuel being delivered when you get on it. This can be due to the idle mixture screws being turned too far out and/or the mixture control solenoid not properly set at height. I've had all these issues before to some degree when installing a rebuilt carb. It's a matter of fine tuning the carb and also making sure the timing is properly set.
#4
Junior Member
Thread Starter
Join Date: Mar 2012
Location: Las Vegas
Posts: 98
Likes: 0
Received 0 Likes
on
0 Posts
Car: 87 Camaro Lt
Engine: 350
Transmission: 700R4
Axle/Gears: 4th gen 3:42, posi, disc
Re: LG4 problems.
So is this something I should let a shop do for me? Like I said, I know NOTHING about carbs. If Its not that complicated, I'm more than willing to learn and do it myself.
"For problem #1, you mean the car runs badly for about 3 seconds after a hot start?" - Yes, thats exactly what I mean. It also smokes black right after this and then everything goes back to normal.
"For problem #1, you mean the car runs badly for about 3 seconds after a hot start?" - Yes, thats exactly what I mean. It also smokes black right after this and then everything goes back to normal.
#5
Moderator
iTrader: (14)
Join Date: Mar 2000
Location: Littleton, CO USA
Posts: 43,169
Likes: 0
Received 35 Likes
on
34 Posts
Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
An '87 will have an in-tank electric fuel pump along with the mechanical pump on the engine. Most people, including mechanics, assume since the car has a mechanical pump, that's all there is. But, obviously, in this case, that's not all there is. When the electric pump fails (and that's pretty much 100% by 20 years), the mechanical pump can still supply the carb most of the time, but under high demand conditions, it won't be able to keep up unless the in-tank electric is also working.
For your problem 1), I'd check the choke pull-off. If that operates as it should, then you probably have "classic q-jet well plug leakage syndrome".
For your problem 1), I'd check the choke pull-off. If that operates as it should, then you probably have "classic q-jet well plug leakage syndrome".
Thread
Thread Starter
Forum
Replies
Last Post
tyeo098
Tech / General Engine
38
11-30-2015 06:27 PM