Carb/Fuel Filter/Cleaning Tips

[OaklandSpider]

Hello Everyone...
Here goes:
Coming home the other day, off a freeway off-ramp, car died as if it had no gas. Just coasted to a stop, dead. Had about 1/4 (little less?) of a tank left. No start, nothing. After letting it sit, checking to see if all hoses, condensors, fuses and everything else was proper, it started up and limped/sputtered home. Getting some gas and filling her up, now idles fine, but sputters and shudders horribly under load, as if it's starved for fuel.
This weekend, I plan on:
1) Cleaning the Carb (never done this before, any and all suggestions are welcome)
2) Checking the Fuel Filter
3) Checking the Fuel Tank Sending Unit Filter
4) Checking the overall rustiness of the tank/seeing what comes out of the aforementioned pieces
I've seen similar posts here about scale/rust/various chunks getting into the Fuel System, and read all the comments/replies...but I'm sure my problem is unique (image one of those little smiley face things).
Any and all suggestions welcome!
Peter

[kilrwail]

Peter - I suggest you check the small lead from the coil to the distributor (high tension lead) to ensure the connectiosn are sound and the wire's not broke somewhere. You could also check the fuel pump to ensure it's pumping clean fuel at a good volume - is it mechanical or electric? Also, check the accelerator pump (on carb) rubber diaphram to ensure it's not split.

[OaklandSpider]

Peter-
Thanks for the tips!
1)I believe the lead wire from the coil to distributor is good, but I'll re-check.
2) Rubber Diaphram-haven't checked yet...are these readily available or hard to find? Where on the Carb is it located?
Thanks in advance,
Peter

[kilrwail]

E-mail sent re: accelerator pump. Remove the outlet tube from the fuel pump and crank the engine over, to inspect the volume and cleanliness of the fuel - better done with a friend and a jar.

[boogiedude]

You also might want to check the float bowl. I learned the hard way that if the needle seat is not tightened properly it can become loose and not allow the bowl to fill properly

[dartme]

If you have not replaced your fuel lines from the tank that might be a good idea if they are old,even if they look ok. Thats what I did and it fixed the problem is easy and cheap to do.

[majicwrench]

I would sure like to see people take a methodical approach to troubleshooting. Basicly figure out what is wrong before just guessing and changing a bunch of parts.

It idles OK, is that correct??

Can you make it run poorly sitting still or just under power??


If it will run poorly while you are looking under hood, try gently closing choke plate, or slowly covering carb barrels with your hand. If it improves, means engine is running to lean. Now you need to see if enough fuel is reaching carb. Pull line, get a pop bottle, stick hose in it, disable ignition so sparks aren't flying around, crank engine 5 seconds. Got your safety glasses on right? Should be a good 1/2 " of fuel in pop bottle. Should produce a nice squirt of fuel out of line if you can watch it. If plenty of fuel gettting to carb, you may have issues inside carb. If not enough fuel, you need to look the other direction, pump, lines etc. Let us know.
Keith

I have a 72 and just coated inside of tank. WHile I was there I replace the lines. The original, fabric coated lines,when cut open, looked just fine.

[OaklandSpider]

wrench-
thanks for the systematic approach suggestion...I try to do things that way myself, after tackling some issues piece by piece, and never really finding out what the problem/root cause was...probably not the best way to REALLY fix things.
1) yes, car idles OK
2) yes, I can make it run poorly while still, not just under load
3) I'll try those suggestions tomorrow...and let you know the results.
Thanks for your time,
Peter

[ga.spyder]

That is a good logical approach.I had a very similar problem recently.SoCalMark suggested that it sounded like debris in the float bowl.Sure enough.it looked like a gravel pit in there.Did a good cleaning and it has been fine since.
Craig

[OaklandSpider]

If it will run poorly while you are looking under hood, try gently closing choke plate, or slowly covering carb barrels with your hand. If it improves, means engine is running to lean.

wrench-
tried covering the carb with my hand, and the idles drops to the point of it stalling. At first, the suction into the carb was VERY strong, after running for a bit with the AIR filter off, the suction has dropped. Does this suggest it IS getting enough fuel, or NOT getting enough fuel?
When this problem first occurred, I couldn't get it to rev past 3000...now it is revving up to 4000 (although I can't get it past that, even while floored)
What could this mean?
Suggestions?
Thanks,
Peter

[OaklandSpider]

If it will run poorly while you are looking under hood, try gently closing choke plate, or slowly covering carb barrels with your hand. If it improves, means engine is running to lean.

After taking the carb off, thoroughly cleaning it, replacing the front fuel filter and some other hoses, putting the carb back on and starting it up...it idled just fine.
Although this time, when I covered the carb with my hand the idling revved higher...
Was about to begin checking from the carb back to the fuel tank when a radior hose blew, spewing coolant all over creation...
Guess what I'm doing next weekend?
Anyways, feel as though the carb is not the culprit here...I'll begin tracing lines back to the fuel pump to see what's what...
Peter

[OaklandSpider]

Hey All...
spent all day replacing fuel lines, lines to Vapor Canister, and a couple of other hoses. After a bit of a sputter, she fired up. Let her idle/warm for a bit (4-5 cycles of the fan coming on). She idles nice...but sputters/coughs when I hit the gas. Took her for a short drive around the neighborhood, and she wouldn't get above 25 mph...really weak. I'm starting to think/hope she is starved for fuel. So...
1. where is the fuel pump?
2. where is the fuel filter?
I spent quite a bit of time under the car and can find neither...
Also, where on the carb is the float bowl?
I'm hoping these are the culprits...again, she was running fine, until I got low on gas, and she just died...
So, I thought it was just a matter of junk getting into the filter/pump.
Again, any info would be helpful
Thanks,
Peter

[maytag]

scanning your post and reviewing the symptoms, I'm unconvinced it's fuel / carb related.

Going back to MagicWrench's suggestion of the methodical approach (which I appreciate him pointing-out) did you pull the fuel-line and physically check the fuel flow?

There are not very many things that can go wrong in the carb which would produce the sudden, drastic change in the way the motor runs, the way you've described. Blockage in the fuel line is one of them, so this is paramount in your search, and a very, very easy check.

Assuming you ARE getting good fuel flow to the carb, then we need to talk about other places to look. I have a hunch / suggestion, but I don't want to start you looking at these other things until we've ruled-out the places you're already looking. (I would like to know more about the radiator hose blowing. Are you running hotter than before?)

[majicwrench]

Peter,
Didn't you already replace the fuel filter??
I wouldn't worry about where the fuel pump is till you have a reason to look at it. See my above post about pop bottle, safety glasses etc.
Float bowl is part of carb.
You ran it till the fans cycled 4-5 times?? On my 72 that would be about an hour of idling. How often do your fans come on??
(not that that would make it run poor, but...)

Not likely that a fuel line would plug, unless it colapsed. Again, test with pop bottle, safety glasses, kill ignition....

You say it idles fine, so I assume that means smooth and around 700rpm??
While under the hood with the engine running, if you open throttle will engine rev up to speed??
Keith

[OaklandSpider]

wrench-
1) I replaced the fuel filter in the engine bay...not the one in the back...which I am suspecting is blocked.
2) Where on the carb is the float bowl?
3) Yes, it was idling for close to an hour...maybe more??? Just wanted to see if any junk would dislodge itself in the running process. Didn't seem to...
4) It's idling around 1000rpm.
I'll try the bottle/safety glasses method and report back.
Peter
PS- changed a condensor that I noticed was bad...made some improvements. Ran it around the neighborhood again this AM...same issues, sputtering like it's starved for fuel. Some good torque in the lower RPMs (2-3k)...very weak in the higher RPMs (3.5-4k)...also, when going DOWNHILL, for some reason, it began backfiring.