Cliff's Quadrajet Parts and Rebuild Kits
Quadrajet Problem Solving => Diagnose a Quadrajet carburetor problem => Topic started by: kenn on October 19, 2013, 01:36:47 PM
-
Hello I rebuilt my carb with cliffs hp kit and some help from him and his book but he is a busy man so I thought I would ask here.
The idle runs rich enough to smell it at the exhaust. (Not after idle) So I think the idle system needs to be looked at.
Idle tube .037
Air bleed's .070
Idle restriction .054
I was woundering if I should open up the upper air bleed or close the restriction?
I know the bleed would be easer but I think the restriction is a bit to open.
Thanks.
-
What's the combo? How's the timing?
-
The combo basically is a mild sbc for work on highway by an old guy that is trying his hand a complete rebuild. It's been going good with some problems but that's what it for takes me to learn sometimes. Like when the book states to start small and enlarge if you have to, I think that's my problem with a rich idle. The restrictions are to large allowing the mixture to be to rich.
I think it would work with .051 but I don't know how to make them smaller (.054 now) or if they are just replaced?
I also think I could enlarge the upper bleed but I'm not sure about that.
Thanks for your help.
-
I still think I need to make the idle down channel smaller. Can I pull them out and install a sized plug? Is the depth of the restriction important? Thank You Sorry about long post.
I have a 72 c 10 with a stock 350 trany, 3.08 rear end. Timed at 14BTDC
350 sm blk .30 over, flat top pistons. aluminum 2.02 int 64 chamb , performer intake.
Quad Recipe;
Idle tube: .037
Down chan: .054
Upper and lower air bleed at .070
Acc discharge holes:.030
Main air bleed .083
Main jet: .074
Main rod: 50M
Fuel inlet: .135
Float level: .250
secondary tube restriction: .033
Secondary hanger: M
Secondary rods: DA
Secondary spring: 1/2 Turn
Bypass air : .046
-
the idle down channel restrictions are replaceable. (95% sure) the bleed can be "peened" smaller and redrilled. What cam does this thing have??
-
Sorry I forgot the heart, Its a comp XE268H-110 224/231 LS 110
I think the bleed is size is ok. I'll call cliff to see if he has these.
Thanks Again. K.E.N.
-
We sell drive in or screw in airbleeds for that purpose. The casting can be tapped for the screw in bleeds, well worth the effort if you are in to custom tuning and want to make changes easy.....Cliff
-
Sorry this took so long but I have not even started back on the truck yet.
Thanks cliff ,after seeing your reply I remembered that I have a pair of the bleeds that I bought from you earlyer. I will not go to large to start with this time.
Thanks Again. K.E.N.
-
Hello, I removed the restrictions and installed the new ones but have not started the truck.
A note about the restriction passage, I found it to be tapered as it went down?
-
This was done so the factory down channel restrictions stopped and were tight in the casting just below the upper idle airbleeds....Cliff
-
Thanks Cliff
-
Hello I have been fighting this thing to the point of despair.
The carb seems to run fine now after I get the engine warmed up but I have to nurse it there.
After it sits over night there is no pump shot ?
Now I have checked and double checked the obvious things that I have learned from reading this sights posts and I am no dummy but this is the last hope before I break down and by a new carb which I don't want to do.
Float level is .25 , Cliffs ACC cup and the ball does not drain down after two days when the carb is apart.
-
i think you have a fuel delivery problem . easy way to check this. get an electric fuel pump . napa sells them for about 40.00. also get (if you dont have these parts )a fitting to screw into the carb. 5/16 0r 3/8 hose to 3/8 inverted flare thats the carb fuel line thread. put a couple of wires on the pump to reach the batt. get a bucket of fuel (quart ,gallon whatever you have and hook it right to the carb. turn it on for 30 seconds and try fire it up . this will help you fiqure out whats wrong. maybe a bad fuel pump something in the line . its anybodys guess .fwiw
-
Thanks for reply
I will check fuel delivery system.
-
one other thing you might try. they make a fuel filter that goes right in the carb that has a check valve.its exactly like the one in the carb except it has a check valve this would help determine if you have a bleed back problem.(ex no vent on the gas tank, restricted fuel line all kinds of stupid little things
-
Hello
The fuel filter was covered in rust it was not completely blocked but it must have allowed enough fuel thru to run but not enough to fill the bowl completely while I was working on it.
Looks like I have more problems to take care of.
Thanks for the help. K.E.N.
-
Hello