carb cleaning

[mik]

Put in new plugs, car idles rough at lower rpms and dies when I push choke all the way in. I have been reading about the use of carb cleaners, some give direction that with the car running, you can spray into the carburetor to help clean it out. Others say do NOT spray down the throat of the carburetor. I would like to give this a try before I bring it to someone to tear it down and clean it. Can I use the carb cleaner directly into the carb. Please bear with me, total novice, thanks.

[majicwrench]

Yes, you can spray into carb. Realisticly sprraying carb cleaner is not going to fix anything. Typically the idle/slow speed circuit is plugged, or the mixture may just need to be adjusted.
Keith

[azruss]

carb cleaner is a complete waste of time. carb will need to be disassembled and cleaned. Not a difficult job other than keeping track of all the parts. Understand that many part look identical with the exception of a number printed on them. that number is the size and needs to go back in the same spot. After you do it a couple of times, you learn where the dirt builds up and will only take a few minutes to remove and clean those jets.

[mik]

does anyone out there have an old carburetor that they know is bad I could practice on, I would like to be able to practice on one and know what I am getting into, before taking mine apart. my car is a '69 124 spider and has stock everything. give me an idea of what it would cost, I would appreciated the help, thanks.

[majicwrench]

I would not recommend taking apart entire carb. If adjusting the idle mix doesn't take care of it, and it has no serious vacuum leaks, runs good other than the idle issue, I would clean the idle circuit.
Have you tried adjusting the idle speed/mixture??

[mik]

no, is there a best way to set the mixture screw and idle mixture screws, based on needing throttle pulled out to keep it running? when you refer to idle circuit, your are referring to linkages, return springs, levers etc. outside carb?

[bradartigue]

Does it have an idle stop solenoid? This would be a barrel like thing screwed into the side of the carb with a 12v wire hooked to it. If it isn't working then you don't get fuel at idle. Check that, then give the car a basic tune-up (which includes setting the carb mixture and idle position). I have a complete section on that here:

http://www.artigue.com/fiat/books/Artig ... 124_MM.pdf

Carb cleaner is good if the throttle plates are black and nasty. You can also remove the jets and blow carb cleaner through the orifices with the carb installed on the car (make sure you get a can with the little plastic straw). I would suggest that if a basic tune up and blasting through the carb with cleaner don't heal your wounds then start thinking about taking it off to clean and adjust.

[manoa matt]

How was the car running before you changed the plugs? If it was running fine, then the problem is with the plugs or wires and not the carb. You could have a bad plug or when you pulled off the wires, broke the connection in one plug wire. You may be running on 3 cylinders. If you have an inductive timing light or a spark plug checking screwdriver with the light in it, check all the wires to make sure none are dead before moving on to the carb.

[mik]

I don't see an idle stop solenoid? Will take a closer look. The car ran similar before I changed plugs. I will test the wires, but think it is more a problem of being gummed up inside or needs idle adjustment. Thanks for the ideas. Really would like to be able to take care of this myself, planning on bringing it in to have the car stripped and repainted at the end of the month.

[majicwrench]

That 69 does not have an idle soleniod. Wires not likely issue. Need to set and or clean idle mixture.
Idle/slow speed system inside carb supplies fuel and idle and slow speed (duh) and has a tiny little jet that plugs easily. Find a diagram of carb and you will see idle/slow speed jet behind screw up near top of carb. There is one on each side of carb, one for each barrel.
Mix adj screw is on base of carb facing out towards LF fender. On my 72 takes a pretty short stubby screwdriver, and it has a nut with a 8mm hex lockingit. A short piece of vacuum hose 1" glued onto slotted end of mix screw makes it much easier to adjust. Loosed locknut and turn screw, out will make it run richer.
Keith

[mik]

looking at a diagram, are you referring to what they call the primary and secondary idling jet? just want to make sure I am looking at the right thing. thanks

[majicwrench]

Yes, those are the ones.
Try turning idle mix out before taking out jets to see if it improves issue. If it does not........
Here's what I have done on many of these carbs, and have to do on my 72 every now and then.
Remove idle mix screw from carb base.
Remove both idle jets. Something they come out with the "idler jet carrier" -the screw- and sometimes you have to use a pick to get em out.
Remove jets from carriers (screw) they just pull out.
Jets have TINY hole in em. Carb clean it, compressed air, maybe even a strand of copper wire.
Now before putting it back together, carb cleaner inside were jets go. Compressed air. Got your safety glasses on RIGHT?
Working on a spotless clean surface so you can find anything you drop RIGHT?
Now put it all back together. Turn idle mix screw in till it just seats. Turn back out 3 turns, that should get it close.
Get back with us.
Keith

[DUCeditor]

This thread has moved past the use of a carb cleaner but before I'd do anything else I'd run a tank of Chevron Techron through if she's running at all. This stuff is amazing. It's purpose is primarily as a carbon remover and as such it is so effective that Yamaha repackages it as "Ring Free." But several mechanics I know swear by it as a general carb/FI cleaner and add it to the tank of every car that comes in with fuel delivery issues. (One mechanic tells me that half the credit he receives as a problem solver should really go to the Techron)

Yamaha's packaging says that the oil and filter should be changed after a treatment - it is that effective at cleaning out the gunk. I use it regularly in all my vehicles. Sometimes the improvement is night and day.

If you purchase some make sure it is the concentrate. Chevron also sells a diluted version for general carb/FI cleaning. That is not the stuff.

-don

[mik]

thanks to everyone for the suggestions. I appreciate the detailed responses. based on your detailed direction, I feel pretty confident I will be able to follow through. Also, I will be able to do this on a regular basis to avoid the same issue in the future. Sometimes it is assumed everyone is very familiar with their cars, and I am trying to get to that point. Thanks again.

[bradartigue]

thanks to everyone for the suggestions. I appreciate the detailed responses. based on your detailed direction, I feel pretty confident I will be able to follow through. Also, I will be able to do this on a regular basis to avoid the same issue in the future. Sometimes it is assumed everyone is very familiar with their cars, and I am trying to get to that point. Thanks again.

Ah, I missed in the thread where you said it was a 69. If you aren't too familiar with cars or FIAT Spiders in general then take a sec and make sure it is all stock on the intake side, that the carb is a DHSA (it says on the carb base) and not a DFH (which was stock on the cars in Europe). That info will be important if the cleaning doesn't get it going.