carb cleaner - phsycological or not

[ski4evr]

I've been battling with stumbling from idle for awhile. It's never been consistent so it's been difficult to pinpoint the source. Today I completely backed out the idle mixture screw and squirted in some carb cleaner. Let it sit for a few minutes - then reinserted the idle mix screw back to it's previous setting. Stumbling gone. Hot or cold.

If this is truely the "cure" for my stumbling, I'm thinking about doing this every oil change (or something like that). Hopefully, not more often. Again, if this really worked, that would imply that the vac drag lines (channels) in the carb are getting clogged and I probably should look into the fuel lines and tank for debris/fouling.

ski

 

[66Sprinter]

I think its safe to say that any PM you did to your carb, if done right, would have a positive affect and wouldn't be pyscho!!

In backing out the screw...and cleaning it and the chamber..yes thats good. You may have also had a small piece of grit that is now gone. There could be endless possibilities to this scenario. The most common element of carb failure has prolly been from varnish from the gas or from debris.

How about fuel filters....fuel pressure...and the normal stuff?

 

[CobraSix]

Carb cleaner is good.

I never realized how important until I rebuilt my first 2 carbs and looked at just how small all those holes are in the carb. It doesn't take much to make them dirty and any plugging of them will hurt performance.

So every 5k miles or so, I spray down the carb lightly. Plus, it cleans it up and makes it pretty.

On a seperate note, be sure to do with on your EFI cars to on the throttle body. I do that every other oil change. It keeps the sensor clean, the butterfly clean, and generally helps with performance as well.

Slade

 

[ski4evr]

How do you check for debris in the fuel delivery system?

Thought process:

1) Drain gas tank (there is a drain plug at the bottom)
2) Clean/Inspect the gas tank. What's a good way to do this?
3) Disconnect fuel line at both ends (pump and tank)
4) Blow compressed air down the fuel line
5) Pull out the sending unit and clean/inspect
Is there a screen/filter in the tank at the sending unit/fuel line connection? - If there is a screen, can this be discarded?
6) Blow out the line between the pump and carb
7) Install an inline filter - should this be between the tank and pump or pump and carb? both?
Also, all of the fuel lines are hard, except a 10" section just prior to the pump coming from the tank. This looks like an easy inline filter install spot.
8.) Fuel pump - mine does not have a filter on top, nor on bottom. The two lines come into/out of the top. How do I check the pump out (pressure/volume). The procedure in the shop manual calls for a pressure gage inline with the carb line and a stopcock to allow for dumping to a graduated container for volume. I don't have that stuff. Honestly, I think it would be cheaper to buy a new one than to test the old one. So, what "symptoms" would point to fuel pump problems?

9) Is this all overkill? I think about this every now and then - especially since the car is over 40 years old and has only 95,000 original miles on it (lots of time with the same gas sitting in it).

ski

 

[ski4evr]

To join in with what Slade said...

One of the times that I rebuilt the carb (autolite 1100), I did nothing but replace software and clean it - nothing was wrong with the ball checks, float, needle valve... And the difference in performance was amazing.

ski

 

[CobraSix]

ski,

I love the pre 66 fuel pumps with the filter on the pump. Much better filter then the inline ones for later years. But even with that another fuel filter may be needed. I've never run an inline with the old style pump, but with a new style I ran for a few months, I had one carb get clogged up, even with an inline filter.

Slade

 

[ski4evr]

Are the pumps with the filters on top easy to find? Just ask the parts store for a '65 fuel pump? If I get one, are the filters readily available?

Ski

 

[LaGrasta]

I keep telling myself carb cleaner is not needed as every fuel company is bragging about it's "added fuel cleaner". If I'm getting it in "every tank", do I really need to add more?

 

[Anonymous]

hewy, I still add lead every now and again...

better safe than sorry

see, I am not sure if I have hardened seats....

 

[ski4evr]

I'm not too concerned with the"micro" stuff that the fuel companies can claim their fuels/additives will clean up. I'm working on the "MACRO" scale.

ski

 

[66Sprinter]

You can go to any auto parts store (even the zoo!) and buy a see through filter. A good one to get is the replaceable cartridge kind.

Put this on before the fuel pump and you can monitor the debris coming from you gas tank. Saves alot of effort and is more safe considering playing with the gas tank.

I thought my tank was bad...but I did the see-thru filter and I spent my time and effort on the carb instead. Saved alot of time and hassle not going thru the tank and all.

 

[ski4evr]

Thanks Jammer

ski

 

[Anonymous]

and also, keep the filter on the carb....two is better than one