need help with stock carb fast
Thread Starter
Member
Joined: Oct 2001
Posts: 421
Likes: 0
From: coconut creek, fl, usa
need help with stock carb fast
hey guys,
I have an 87 trans am, all stock with the 305 and a computer controlled carb (I think its called a quadrajet), any ways, some times it idles perfectly, but now most of the time it idles around 16-1700 rpm in neutral and 1100rpm in drive. I used an entire can of carb cleaner on it with no luck, I'm not familiar with carbs so I need major help in detail and pictures if possible, I don't know what to do. also if I rev the engine it comes down very slowly. tai.
------------------
neko
'87 trans am
car in the making
I have an 87 trans am, all stock with the 305 and a computer controlled carb (I think its called a quadrajet), any ways, some times it idles perfectly, but now most of the time it idles around 16-1700 rpm in neutral and 1100rpm in drive. I used an entire can of carb cleaner on it with no luck, I'm not familiar with carbs so I need major help in detail and pictures if possible, I don't know what to do. also if I rev the engine it comes down very slowly. tai.
------------------
neko
'87 trans am
car in the making
Supreme Member
Joined: Sep 2001
Posts: 6,111
Likes: 53
From: Ontario, Canada
Car: 1988 Firebird S/E
Engine: 406Ci Vortec SBC
Transmission: TH-350/3500stall
Axle/Gears: 7.5" Auburn 4.10 Posi-Traction
There are two vacuum diaphrams on the pass.
side og your carb They control the choke and secondary air door. If they either one is not working the choke and fast idle linkage will stick. Test them by removing the vacuum
line and cover the hole onthe tube. depress the plunger and then release while blocking the small hole. If the plunger returns, the diaphram is bad. You can get them any autoparts store.
side og your carb They control the choke and secondary air door. If they either one is not working the choke and fast idle linkage will stick. Test them by removing the vacuum
line and cover the hole onthe tube. depress the plunger and then release while blocking the small hole. If the plunger returns, the diaphram is bad. You can get them any autoparts store.
Supreme Member
Joined: Sep 2001
Posts: 6,111
Likes: 53
From: Ontario, Canada
Car: 1988 Firebird S/E
Engine: 406Ci Vortec SBC
Transmission: TH-350/3500stall
Axle/Gears: 7.5" Auburn 4.10 Posi-Traction
<font face="Verdana, Arial" size="2">Originally posted by silentneko:
the engine has to be running right
</font>
the engine has to be running right
</font>
Thread Starter
Member
Joined: Oct 2001
Posts: 421
Likes: 0
From: coconut creek, fl, usa
ok my carb only has the one diaphram, and I tested it just like you said and it is still working, what else can it be. it does this about half the time, thank you
------------------
neko
'87 trans am
car in the making
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neko
'87 trans am
car in the making
Junior Member
Joined: Jul 1999
Posts: 88
Likes: 0
From: Cookeville, TN
my guess is your electric choke is going bad - mine crapped out on me, and i didn't realize it - eventually it got to the point of the rpms being so high, it kept the motor running after turning the switch off - not a pretty sound at all
i'm not sure how to check the choke, but if you'd like to change over to a manual choke, autozone sells a kit for 5 bucks to do it - kinda neat, but a pain in cold weather situations to get just right - otherwise, i finally replaced mine - with the actual electric choke - costs about 45 bucks from parts dealer
rather easy install if you have a drill to punch out the old studs and a tool to put the new ones in
i'm not sure how to check the choke, but if you'd like to change over to a manual choke, autozone sells a kit for 5 bucks to do it - kinda neat, but a pain in cold weather situations to get just right - otherwise, i finally replaced mine - with the actual electric choke - costs about 45 bucks from parts dealer
rather easy install if you have a drill to punch out the old studs and a tool to put the new ones in
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