Chevyman84

Can some one help me out i broke my old carbs choke and i bout a new one.


the guy a carquest told me no adjustments needed.
i bolted it on and the choke has some problems which im not really worried about... im more worried about the idle and stumble...

when the car is idling it idles and kinda bobles around kinda jumping between 5 and ten rpms......

when i put it into drive it takes off fine but during acceleration it kinda stumbles and hesitates......


The mixture screws were set at 1 turn out......
and i changed them to 5 turns out.... does anyone know what i can do to try and fix this......

Sonix

iTrader: (1)

Alright, one problem at a time here. Choke, or acceleration stumble.

Does the choke work perfectly? Don't settle for less than perfect, showroom floor condition. One tap of the throttle to set the choke on, then crank it over without touching the throttle, it should fire up and idle at 1500RPM cold, rising steadily, then you tap the throttle and it'll kick down, until its at a 750RPM warm idle, that sorta range.

When you take off, and it stumbles, is the choke completely off? Choke flap vertical?

You have access to your mixture screws? Is this a computer controlled q-jet ? I understood those are usually capped, and even when the caps are removed the adjustment you get out of those screws are a drop in the bucket compared to what you get from the mixture solenoid.

Why don't you put some car info in your sidebar eh?

ZONES89RS

iTrader: (2)

Well, my friend and I had that problem on his 85TA, we ended up with a Edelbrock, a simplified Q jet basically, we also opted for a vacuum advance HEI, just a last resort/idea.

Chevyman84

oK well it is a computer controlled carb and i do have acces the the seloniod and the mixture and idle screws......


i can set the choke fine...... the problem is that when i start it up it will stay on high idle for way to long i will continue to tapp on the pedle way after the fan has came on so i know my car is warmed up....... well i just fixed my high idle problem...... the problem was that my choke flange thigy never got completly vertical so when i was tapping it it thought it wasnt completly warm im guessin.... i just adjusted the choke thermostate slightly and it worked....... but my high idle is way to high it at 3000 rpms


How do i adjust my high idle down to 1500???????????????????????????

five7kid

iTrader: (14)

The high idle adjustment is on the passenger side of the carb, on the bottom, and you get to it from the rear.

Sonix

iTrader: (1)

yea, passenger side, but i'm pretty sure you get to it from the front.

Phillips head drive, with a hex as well. It's below, not the one on the vacuum break, below that.

I know I have a good picture with an arrow pointing to it, on my webspace. I'm at a different computer so I don't have the link to it now, i'm sure you can find it, I posted that picture here a few times.

Chevyman84

Right on you guys.................
ill get back to you about that hesitaTION PROBLEM I GOT

five7kid

iTrader: (14)

Good luck getting to it from the front. . .

xgtharo86x

iTrader: (1)

ya i got the same combo but mine non cc and it hesitates soooo much got no power

Chevyman84

Ok sooo what should i do about this hesitation problem i have my mixture idle screws like 1 turn out and it seems to work better........

what i mean is is only hesitates every once in a while its weird its like it hesitates when it wants but by me messing with the screws it did help it alot........

Sonix

iTrader: (1)

I think you're band-aiding the main problem.
You should only use the mixture screws, and mixture solenoid to work with idle issues.
I am not versed in setting up the mixture solenoid, so i'll let someone else help you with that. Normally i'd say to set the mixture screws for best vacuum, keeping the idle speed at 750RPM say. Once you have MAX vacuum with your mixture screws, idle is set at the right RPM, and timing is in the ballpark, then your throttle blades will be positioned to not have a bog/hesitation.

This hesitation is on takeoff with mid throttle, or full throttle? Full - i'd look into secondaries (or hesitation after you're moving), but if it's a hesitation from a dead stop with lowish throttle, then I think you're on the right track already. Hopefully someone here can tell you how to setup your mixture solenoid.

Five7 - we must be on different pages here or something, do you know if a non-cc and cc qjet have the same fast idle setup? I coulda sworn they did, but I only tinkered with a cc setup once, a while ago. Here's my non-cc carb a while back, and this is how i'd hold my screwdriver, except just above the fuel line there. I can't imagine adjusting this screw except from the front...?

edlisaj

yes you do adjust it from the front and on the passenger side

five7kid

iTrader: (14)

I stand corrected. Had an older configuration in my head.

On my CC q-jet, it's a Torx/hex screw. It is a little difficult to get to with the stuff that is in front of it (like the fuel line).

Chevyman84

What exactly should my timing be set at any way i have it at ten right now and also how do i know when i have most vacumm..................??????

and the hesitation occurs during takoff and half way into the pedal!!!!!!!

five7kid

iTrader: (14)

Just to be clear, this is a computer controlled carb, right? That's what I gather from the previous posts.

The base timing should be set somewhere in the 6 degrees BTDC area. "Base" timing means with the flat 4-wire connector disconnected. If you've got 10 degrees at idle with the connector connected, you're way, way too retarded.

Vacuum should not be the determining factor in setting the idle mixture. Set the idle mixture screws at about 4-5 turns out (my rebuild kit said 4-1/2, which worked very well for me). Then, with the timing set correctly and the engine warmed up, set the idle air bleed to get about 30 degrees MCS dwell with the dwell meter set on the 6 cyl setting.

Chevyman84

should i set the mixture screws at 4 1/2 with the car running or off?????

How do i determine dwell??????


and does anyone else have any input????????

five7kid

iTrader: (14)

You can set the mixture screws with the car running or not. I set them on the bench while rebuilding the carb before it was installed again. They're still set at the same place now as they were that day.

You need a "dwell meter" to set the MCS dwell. It's an instrument left over from the points ignition days. There's probably another way to do it, but I've got a dwell meter, so I haven't had to figure out any other method. There is a green electrical connector over by the AC housing that doesn't connect to anything - you connect the dwell meter positive lead to that, and the negative lead to ground.

Chevyman84

i cant find the green coonecter is it by the ac condenser or the ac pump........


i found a green connecter but it does connect to something!!!!!!!

Chevyman84

hello

Chevyman84

when i hold open the choke flange and give it gas i shouldnt see the gas stop shooting out right????because after one or two shots it stop coming out.......i think im not getting enough fuel!!!!

five7kid

iTrader: (14)

If that is with the engine not running, correct, there should be enough fuel in the bowl for several shots. Your float may not be set properly.

jacob_stevens09

I just go rid of my quadra"junk"..is was always givin me trouble so i got a sweet holley avenger

Chevyman84

how do i set float

Sonix

iTrader: (1)

Buy a rebuild kit, it'll have instructions on how to do it, along with some small parts that you may want to use as well. It'll also have nice pictures of how to do it, which make a lot more sense than anything I could type here.

Chevyman84

If Im not mistakin the cold fast idle screw is the one that can be reached from the front and beneath the choke housing.......

well i have tried numerous times change the fast cold idle from 35000 to a lower rpm but everytime i turn the fast idle screw out it has a opposite affect on my warm idle speed .....


so basically i am turning down my fast idle speed but exchanging it for a to fast curb idle speed.....


does anyone know what im doing wrong and has anyone else had this problem.....??????????????????????????

Sonix

iTrader: (1)

your fast (cold) idle speed screw should have absolutely zero effect on your hot idle speed.

Get the car nice and warm, grab the fast idle cam (the triangular head thing that's right behind the vacuum break in my picture), and make sure it's down, like in my picture. That means you are on your hot idle. Then adjust the idle speed via the screw on the drivers side. Once you get it to the desired spec, it shouldn't change.

The cold idle will be based on that fast idle screw that I pointed to earlier. The length of time it sits on the choke, and how cold it has to be to engage the choke, is set by how far you've got the choke thermostat turned, in my picture the electrical connector on the choke thermostat is parallel to the ground, that's a really good baseline to start with. There's another way to set that, but make sure its in the ballpark first.


I'm very quickly losing interest in helping you, and I think Five7 is feeling the same way. Nobody is going to help you with anything if you don't try the advice. Did you set your dwell like Five7 said? Did you put your car info in your sidebar? Did you set your float level?
We're not just talking to hear our own voices (err, see our own text), so why don't you go ahead and try these suggestions eh?

Chevyman84

well i tried to ask you what green connecter i use to set the dwell and i also dont see the picture you were talkiig about???????

five7kid

iTrader: (14)

It's that one.

Sonix

iTrader: (1)

Scroll up man, there's only one picture in this thread so far, my post, #11 in this thread. I've attached a picture, click on it to make it full size. That'll clarify anything i've mentioned.

Do some searching, you should be able to find that connector Five7 is talking about.