Guys,

I gave a hand helping therx7guy666 rebuild his carb on his '80 LS this weekend. I'm not much of a carb guy, but I have done this before on my SA many years ago. Anyway, we have a bit of a problem. We put everything back together and fuel just drips out the main discarge nozzle on all 4 barrels (although the primary on rear rotor seems to be the worst). I tried tapping on the banjo bolts on the top of the carb with the handle of a screwdriver because I remember the sometimes that helps the needle valves seat properly. This didn't seem to help. Floats were adjusted to spec (16mm up and 51mm down). I thought that maybe the float/needle valve assembly was not sealing correctly, so we removed the airhorn, turned it upside-down and tuned the fuel pump back up. Sealed without a problem. Lifting the float let the fuel to flow out as it should.

The fuel pump is aftermarket of unknown brand. There are no markings of any kind on the pump. It is cylindrical silver pump. It is quiet and looks similar to an SE pump, but it isn't. The car ran before with this pump, so I don't think it is really an EFI pump or something like that (didn't have a tester to check pressure).

I know there are some weights/checkballs in the carb. We did not remove them as far as I know. We just removed the jets/air bleeds one-by-one and cleaned with carb cleaner.

The strange thing is that the fuel dripping out does not always happen. Sometimes, we would turn the key on (engine not running) and they would not drip. We would then try to start and afterward they might start dripping like mad. I have already checked that the vent solenoid it plugged in and getting power (I think that it causes flooding problems if not connected if I remember correctly). Power valve solenoid was not removed and is plugged in. Richer solenoid has a broken wire. We tried to strip the wire, shove back in the hole, and tape it in place.

Any ideas? BTW: can any one tell me what the yellow plastic thing under the carb is? It appears to connect to the center iron. It has a large vac line connected to it that runs to the carb base. Anyway, the plastic nipple on that yellow piece was found to be broken and someone had put in a drinking straw to try to fix it.

Thanks.

Kent

 

I have yet to have the floats come out excactly to spec. I always double check them with the sight glass marks. The fuel pressure needs to be 2.5 psi. If it's a AutoZoo special fuel pump, then you will probably need a regulator on it. The line under the carb going to the center iron is probably the purge valve for the crankcase vent. Good luck!

 

Thanks, Sam. It was nice to meet you and the other guys this weekend. I'll come back down another time to take a spin in the turbo FB . When we took off the floats, they were at approx. 20mm up, 51mm down, so I reset them to spec. The sight glass should be check with the engine running, correct? We could get it to start, but it was running super crappy.

I figured that a regulator may be required. I couldn't believe that the pump has 0 info on it. Not even 12v, # psi, or brand. Nothing at all!

 

Is the fuel level in the center of the site glass when it drips?

PCV valve.

 

Honestly, we had a hard time telling. It was probably full... To me it seems like floats/needle valves, but I'm not sure. I don't live close by, so it is hard for me to troubleshoot it. If there are some simple things he can try, that would be great. He doesn't have internet at his house, so he is not able to post/check on here frequently. I can relay any info to/from him, though.

 

I spoke with him last night. He pulled the floats and found one was tweaked a bit. He corrected it, but it is still dripping, but only on one side now. He is going to try to reset the floats to their original positions (20mm up, 51mm down) and see if that cures the problem.

Edit: Also he said that he found some milky stuff on his dipstick (not what you are thinking, Wacky ). Probably due to his messed up PCV system. He said it was clear when he bought the car, but perhaps the seller changed the oil to hide the problem... Also the car has been basically sitting for about 6 months since he bought it and was sitting quite a bit before he bought it too.

 

I would use a small mirror and a bright flash lite to check both float bowl sites ...fuel level should be in the center,tweek floats to attain this(check this at idle).Also check needles and seats for good seal when you are tweeking float level .good luck.

 

That milky stuff indicates poor crankcase ventilation(PCV).One way to solve this is to run a vacuum hose from crankcase to the airfilter housing with a one way check valve in between;also drill a 1/8" hole in the center of the oil filler cap.this eliminated the moisture buildup in my engines

 

Sure sounds like a float/seat issue, considering that the car ran before. Otherwise, I would say it needs a FPR on it.

There are a lot of different opinions on the solution to the lung mustard. I have found that the simplest solution worked for me. All I did was run a vacuum line from the nipple on the oil filler tube to the base of the carb. Close to two years now with no issues, and no lung mustard....

 

Thanks, guys. That is what I was thinking too. We'll see what he comes up with and I'll let you know. Maybe we'll do the rats nest removal the next time I am down. We already simplified the carb (he has a manual choke, no A/C). We removed the sub-zero bottle and the hot-start assist. Have any of you guys removed the rats nest on an SA before? I'll look at the FSM about the ACV, but want to make sure we don't overheat/collapse the thermal reactor.

 

It could be a little bit of rust or something from the tank that got jambed between the needle and seat. I have had this happen before.

 

Bump?

 

I worked on the car yesterday only one jet is leaking, the bottom left if you are on drivers side, i got her to run and idle at 1000, she reved ok to about 4000 kinda chokey....but she died and after that, wouldn't even attempt to start back. got the air pump back on no exhaust smoke other than minor smoke from running rich or lean or which ever it is. Thanks for the advice and comments thus far.

 

Do you have fuel going to the carb?

 

The problem is too much fuel if anything. One of the main nozzles is just dripping fuel like crazy. When I was there last, it was rotor #2 primary that was the worst offender, but all were dripping at that time. It sounds like rotor #1 primary is being the culprit now. I am just not sure what would cause this. I could see 2 barrels or all 4 overfilling (floats/needles valves not working allowing overfilling of bowls).

Hopefully we can get it figured. Otherwise, we may need to slap on a good used carb. We do need to take the carb back off to fix that PCV valve that is broken anyway.

 

Did you remove what the FSM refers to as the "restrictor" from the return line, by chance? That's actually a check valve, and if it gets turned around, you're effectively dead-heading your carb. If your pump is a piston design (like stock) then it's just going to keep trying to build pressure. I tore one apart and didn't see a bypass in it, but that was years ago.

 

The white crap is condensation emulsified with oil vapor. The engine needs to run fully warmed up for a decent amount of time to get thaty all sucked in via vacuum port (large mouthed vac. port, if possible to prevent blockage).

 

No. We didn't remove the restrictor on the return line. I also remember looking at it and the arrow was pointing the correct way (I think). Doesn't the arrow say "to car" or something like that? Arrow pointing away from engine? Anyway, I'll have him double check to make sure. I don't think that his pump is the piston type. You do not hear it clicking when running and it looks like a cylinder with the inlet/outlet on each end. It looks more like the GSL-SE fuel pump Anyway, I did try blowing through the return line because I was also thinking that the return may have been blocked. I could blow through it, but there is some resistance... probably due to the restrictor.

We wanted to test fuel pressure, but we didn't want to buy a tester and couldn't find one to borrow. I asked the guy at Autozone about the tester they had (for range, etc.). He said that he didn't know how to use one of anything about them... He said "Oh, do you plug that in to your radiator or something? ". I was like ..

 

Kent, I can get a inline adapter and gauge from a local speed shop for around $20 bucks. All you would need for a regulator (if needed) is one of the Mr Gasket ones they sell at Advance. I am using one of those on the SA. Does fine with the Holley or the Nikki. With the Nikki on there, I just turned the regulator down to 2.5 psi, and it runs fine. The next time you go up there, give me a heads up before you go, and I'll see if I can go with you.

 

Sounds good, Sam. I'll let you know. I don't know when it will be as I have a lot of stuff going on myself. The testers that we saw were also like $20, but he doesn't want to pay for something that will just be used that 1 time. I have a tester myself, but it is for EFI. I suppose we could have goofed something up in the rebuild. We were pretty carefull, though. There was a lot of crap in the carb (especially behind the AP diaphram). We cleaned all that stuff out, but I suppose that some of it could have made it in somewhere causing this problem.

 

If there's crap in your emulsion tubes, the fuel will have a tendency to siphon at any appreciable RPM.

 

well yesterday i got it running, it idled at 800-ish a little shaky but no leaks at all i drove it for a while i only had a gallon of gas in it. it ran out of gas so i got another 2 gallons, it refused to start back...today it started and choked after about 10 secs and then the carb started flooding again....the floats are worn out from being adjusted too much (my bad)... i removed the two screens that sit in the chamber where the valve seats go...( i think thats right)....they would not stay in place and were getting in the way and one of the float jets was missing an o-ring....i think if i can get another set of floats and valve seats (if that is what they are called then the problem should be fixed.

also when the car was running it smoked alot mostly from that smaller pipe next to the exhaust but it did it mostly 3/4 back not at the very end but the smoke cleared up, she purred and drove very well until it leaked again.. it seems to me they sit it place right but then get knocked out of place...im not sure but i honestly belive that the floats are my main concern and maybe the fuel pump.

 

I have a couple new seats if you need them. If you guys put a kit in the carb, did it not come with new needles and seats? If you are running too much fuel pressure, it will overpower the floats and cuase fuel seapage in the carb also.

 

We did put in new seats (well he put the seats in later as we couldn't get the old ones off at the time) and needles. That is why this is so confusing to me. We even tried taking the airhorn off, turn upside-down, and turn the fuel pump on. No leaks at all.