: Carburetor Questions



GeneLaw1
04-07-13, 11:44 AM
Good people,

I have recently installed a reman carb on my 89 Bro with the 307. The car runs well but when I kick the choke off it a putters and dies. Any ideas? I've been working with adjusting what I believe to be the choke plate, a black circular thing in the side....also what I believed to be an idle speed screw in the front. Either way, I just need some assistance. I was able to drive last night with no problem really other than the engine light flickering in the interstate.....this morning, I started let it run, and tap the gas and it sputtered off. Haven't been able to get it started again, haven't tried too much though.

Appreciate any advice....thanks!

jayoldschool
04-07-13, 12:30 PM
Check out this video, and the other vids by this guy. They will probably help you understand what the adjustments do.

http://www.youtube.com/watch?v=yX_hCujFQ_I

GeneLaw1
04-08-13, 08:54 PM
Check out this video, and the other vids by this guy. They will probably help you understand what the adjustments do.

http://www.youtube.com/watch?v=yX_hCujFQ_I

So Jay after watching a couple of these, I wanted your opinion. Is it usual to have to adjust the mixture screws and idle speed screws after putting on a new carb?

jayoldschool
04-08-13, 10:35 PM
Yes, the carb is going to need to be set up when putting it on. A tach and a vacuum gauge are essential. The benefits will include smooth operation, more power, and better fuel consumption.

GeneLaw1
04-09-13, 12:48 AM
Yes, the carb is going to need to be set up when putting it on. A tach and a vacuum gauge are essential. The benefits will include smooth operation, more power, and better fuel consumption.

O boy, I have none of that stuff, nor do I really know how to use them...guess it may be time to find a shop, I at least want to get it to where I can drive it to one. At hot idle sometimes it barely even runs. smh

1980coupe
04-09-13, 04:21 AM
When I got my new carb, all I did was slap it on and reconnected everything and it ran fine. I made no adjustments
whatsoever and ran fine. Still runs good, even though I had the caddy sitting since October of last year..
Good luck with your adjustments.
Good to hear from you and that you're doing fine after what happen...

jayoldschool
04-09-13, 12:12 PM
Gene, do you have a Harbor Freight near you?

GeneLaw1
04-09-13, 11:49 PM
When I got my new carb, all I did was slap it on and reconnected everything and it ran fine. I made no adjustments
whatsoever and ran fine. Still runs good, even though I had the caddy sitting since October of last year..
Good luck with your adjustments.
Good to hear from you and that you're doing fine after what happen...

O yea man, Didnt miss a beat. But I had to get that Caddy out of there, it was running pretty bad on the old one...but it was running better than it is with the new one...ugh!

----------


Gene, do you have a Harbor Freight near you?

Harbor Freight Tools? If so, then yes there are a number of those around Atlanta.

----------


Gene, do you have a Harbor Freight near you?

Harbor Freight Tools? If so, then yes there are a number of those around Atlanta.

silverfox103
04-10-13, 01:04 AM
I've replaced a number of carburators with rebuilt units in my 64 years. I have never had to adjust them; there ready to go out of the box.

Tom C.

jayoldschool
04-10-13, 01:07 AM
You never bothered to set idle speed, nor mixture? A carb will run (usually) out of the box, but it will be better if it is at least checked.

silverfox103
04-10-13, 10:03 AM
You never bothered to set idle speed, nor mixture? A carb will run (usually) out of the box, but it will be better if it is at least checked.

I have not, if I remember correctly, there was always a note with the instructions, that no adjustments were necessary as they are factory set from the rebuilder. Now with everything FI, I can't remember the last time I bought one. It may be 25 years ago.

Tom

GeneLaw1
04-10-13, 01:59 PM
Maybe something happened during the installation of mine....vacuum leak perhaps?

cadillac_al
04-10-13, 08:58 PM
Did you play with the adjustments showed in the video? If that one didn't do the trick I'll bet there are a lot of other videos explaining it around the net. It sounds like a choke adjustment is all it needs.

GeneLaw1
04-11-13, 02:57 PM
Did you play with the adjustments showed in the video? If that one didn't do the trick I'll bet there are a lot of other videos explaining it around the net. It sounds like a choke adjustment is all it needs.

The idle screws I did play around with. I was attempting to play with the mixture screws but I didn't seem to have the proper tool to turn them.

csbuckn
04-11-13, 03:10 PM
Can you see the fuel coming out the jets in a good streem?

The Ape Man
04-12-13, 07:49 PM
In a 1989 car the carbonator should be already adjusted out of the box.

I second looking for a vacuum leak, mis-routed vacuum line or a clogged vacuum line to the MAP sensor.

jayoldschool
04-12-13, 10:08 PM
I completely agree, it SHOULD be adjusted out of the box, but it is always beneficial to check the settings. Everybody has a bad day at work every now and then... even carb rebuilders ;)

The Ape Man
04-13-13, 10:49 AM
I completely agree, it SHOULD be adjusted out of the box, but it is always beneficial to check the settings. Everybody has a bad day at work every now and then... even carb rebuilders ;)

The choke thermostat has a detent and no adjustment. Curb idle means little or nothing because of the idle speed motor. Idle mixture would need to be set very carefully because it overlaps the operation of the mixture control solenoid.

Primary choke pull-off adjustment still works like old non-feedback Rottenchesters but his symptom does not match a mis-adjustment problem here.

There's a good chance adjusting this thing will screw it up.

If it runs poorly there's most likely another problem somewhere which was missed : (

cadillac_al
04-14-13, 09:19 AM
I still say it just needs a choke adjustment.

The Ape Man
04-14-13, 04:23 PM
I'd get rid of whatever is making the check engine lamp lighting, fall back 10 and punt.

GeneLaw1
04-17-13, 07:18 PM
OK update, I took it to a shop here in Atlanta that works on old Cadillacs, they informed me the carb is bad. Its not getting gas to the engine when the choke is closed....

jayoldschool
04-17-13, 07:52 PM
Glad it got figured out.


Everybody has a bad day at work every now and then... even carb rebuilders ;)

The Ape Man
04-17-13, 08:02 PM
Sounds like they figured out how to pick the guy's pocket.

GeneLaw1
04-21-13, 09:43 AM
Glad it got figured out.



Indeed, because ur was stumping me....when I have time to get it back off....back to the store I go smh

caddywarewood
04-21-13, 09:43 PM
I have an question i have an 84 deville and im thinking about switching the ht4100 for an 425 or 350 which will be better or easier fit without many mods

cadillac kevin
04-21-13, 10:53 PM
I have an question i have an 84 deville and im thinking about switching the ht4100 for an 425 or 350 which will be better or easier fit without many mods

You should start your own thread for this. Simple answer is either will be a direct bolt in (but you will need to get the correct mounts and transmission)

csbuckn
04-22-13, 10:06 AM
The 425/th400 combo will bolt in without moving the motor/tranny mounts but will need a new driveshaft and your rear gears are not the best for gas mileage. The 350/th700 combo may require you to move the mounts but may not require a new driveshaft and the rear gears are ideal.

Mark 78 Coupe
04-27-13, 11:36 PM
I have a general carb question. My 78 Coupe has 45,000 original miles. It obviously sat unused many years (at my parents house), and then many more at mine. Last year, I changed the leaking rad, put in all new hoses and belts, oil change and coolant. It starts almost instantly, does the fast idle thing, then slows down after a minute or two to a very smooth idle. However, when I go to drive it, it stalls, or almost does. I have done nothing to the carb, mostly out of fear of doing more harm than good. I have not yet checked all the vacuum lines. Could the choke be bad, or stuck? Even when it is warm, it stumbles when I press the gas pedal. Any thoughts? Thanks.

jayoldschool
04-28-13, 12:15 AM
Accelerator pump is bad. Diaphragm is likely torn. Easy fix.

csbuckn
04-28-13, 01:40 AM
Thinking acc pump also. Cant you check the pump by pulling the throttle back and seeing if any gas comes out?

caddywarewood
04-28-13, 02:41 AM
what do u guys perfer manual or electric choke with an 77 deville
is there any kits i need or can i slap this on from an manual to electric out the box other than the wiring

deVille33
04-28-13, 09:07 AM
The electric choked 425 was very reliable. A lot of people don't like the Rochestors, but if rebuilt and adjusted properly, will perform admirably for a long time. Concider the fact that there are several out there still working well after forty years.

Mark 78 Coupe
04-28-13, 08:01 PM
Accelerator pump is bad. Diaphragm is likely torn. Easy fix.Thanks. Is that a common part I can get at NAPA or the dealer? I don't know what make carb it has, but it is the original. Is the pump the part that moves up and down, on the driver side of the carb, ( I think) when the gas pedal is pressed down? It just comes out?

cadillac_al
04-28-13, 08:38 PM
You should read some articles on rebuilding Qjets. It's not hard but there are a few little tricks to it. Since you are taking the top off, it doesn't take much longer to refurbish the whole carb. It can be intimidating though so a good book or some good articles will make it easier and less intimidating.