mikewoodkozar

I am pretty sure that it is not boiling, i may have said that to give you an idea of what it appears to be doing, but it is the fuel pressure that is constantly flowing into the carb making it appear to be boiling. Temps are normal

mikewoodkozar

Okay, so its cold and rainy here in Michigan so i took the car up to my local mechanic (whom is a friend of mine) and he took a look at in his shop.

This is what he told me, "the fuel pump continues to cycle after the car is shut off trying to keep pressure in the line."

WHAT?! I though that the fuel pump turns off after you turn off the ignition, am i correct?

Why would it continue to keep and put pressure in the line for up to 35-40 minutes? I mean, seriously, we are not talking about the small fuel that is left in the lines, we are talking about a constant stream of fuel, enough to flow over the top of the carb, onto the block and finally on to the ground.

If that is the case, and in theory, if i wired up a switch to cut off power to the fuel pump wouldnt that stopp the whole issue?

Bigmotoxer

yes it would.
that's what alot of peeps on here have(a switch for the fuel pump)including myself. I like to be able to turn it on or off easily...put a fuseable link in so if ever shorted it will blow fuse and not burn something up though, and as many have said "it's a good anti-theft switch" if you put switch in a good location. I wonder if you have the stock fuel pump? and how many psi it is delivering when it is running? Add a fuel pressure regulator up close to the carb...set it for 2-3 lbs.
This is info I've just learned in recent months myself, goodluck.

tunafish

It would appear you have ignored my post regarding the Coasting Valve
I seriously doubt your fuel pump is running after the ignition is off.
I believe in the end you will find a vacuum leak on the carb that is allowing fuel to flood once the ignition is off. Check your vacuum lines and caps on lines you may be using

Bigmotoxer

I don't think anyone ignored you brother and I was just thinking that if it was a vacuum why would it affect carb after car was shut off...when there is no vacuum? And from my recent experience w/overflowing carb I seen that it would just simply over flow/flood until problem was corrected(whether it's floats, needle, gasket, ect)but it wouldn't bubble or gargle. So I was thinking "Trochoid may be right about having some freakish overheating , boiling, vapor locking, ect" then I thought but what if it's simpler than that, "hey the fuel pump could cause a gargle since it's a pump and whatnot". knowwaIsayin?
Anyway if his mechanic says his fuel pump isn't shutting off them maybe that IS it. Unless the mechanic was just guessing and didn't actually check it out.

innertwist

iTrader: (3)

Now, you definately want your fuel pump to shut off when the car is completely off. At the very least it'll drain your battery. But that isn't the main reason your car flooding.

I drive an SA, so the fuel pump turns on when the key is in the on position, engine running or not. Now I could leave the key in the on posistion for over an hour and it's not going to let a single drop of fuel into the engine. That is unless my needle valves are stuck open, and I've had that before too. When they're stuck open, once the float bowls completely fill up the easiest escape for all that fuel pressure is the jets, leading to the type of flooding you're getting.

The most common reason for the needle valves getting stuck open is some sediment made it into the carb, and is now sitting between the needle valve and it's seat. At the very least, without going in to a complete carburator rebuild, you should take off your bowl cover and clean out all the plumbing. That is, remove the top portion of the carburator. Holding it on are about eight or nine screws, the center bolt that also holds the air box, the choke return spring (which is held on by two screws), the fast idler arm, the choke linkage, a hose and wire for the vent solenoid, and maybe something I'm forgetting. After removing everything be careful when lifting the bowl cover off the carburator. If you tip it sideways the pins holding the floats could pop out. Assuming you're doing this with the carb still the car, this can be hell because the needle valves will also fall out. If you brake the gasket you'll have to order a whole set, at which point you might as well do a complete rebuild of the carb. Might not be such a bad idea to do anyway.

Anyway, dissassemble the bowl cover and clean it out throughly with carb cleaner. Spray into every passage. Don't forget about the screens under the banjo bolts. Alot of crud buildup on the screens and primary fuel passages is a sign of a faulty filter/dirty gas tank. You can check your float levels while you have the cover off too, but I recommend against adjusting them unless you accidently bent them in this process. Once it's all cleaned up and reassembled, hold it upside down so the floats will put some pressure on the needle valves. Cover the one fuel line and try to blow into the other. If you can't blow in at all, good! You've fixed it! If you hear a tiny hiss from one of the valves, and it's been competely cleaned, that valve will need to be replaced.

Having done all this you don't want it to happen again. Replace your fuel filter. If there was a considerable amount of crud, place another fuel filter between the carb and the sending hose. If that's the case, clean out the float bowls too. You don't want to put it all back together just to have one of the jets clog down the line.

innertwist

iTrader: (3)

hmm, just re-read the post. I jumped the gun. If your can idle without flooding then the needles aren't stuck. SORRY! By any chance are you running higher than stock fuel pressure? Enough pressure could forcefully open the valves.

trochoid

iTrader: (6)

If the fuel pump is still runing after the ignition is shut off, then someone has rewired it wrong. However, if that's the case, it would not shut off until either the battery ran down or the pump overheated. Something is definitely not right. Even if the carb is overflowing, for whatever reason, the fuel should not be percolating and have bubbles in it.

You have an odd problem that I've not seen before.

Bigmotoxer

the guy that posted this thread hasn't posted responded on this issue for a week now, I wonder if he found the problem and just didn't respond back? I would like to know what the bubbling fuel was all about.
Where are you dude?!

mikewoodkozar

I am still here and i still have no idea, i started to source parts to put together a weber setup, holley fuel pump and fpr. Figured i would (hopefully) nail all the issues with that setup

DLxAminer

I have the exact same issue that has occurred 2x in the last month. I don't hear my fuel pump running. My 83 is set up identical with the RB header and no smog. My last trip out I flipped the efan on as I came back into the city limits (10blks@25mph) and ran it until I got home for about 2 minutes after I shut down. I didn't flood or overflow this time. I just bought this project and am new to the group but so far your information has been priceless to me. I'm lurking around this thread and will post anything further in my attempts to track down the issue.

trochoid

iTrader: (6)

Welcome to the forum and the Darkside. Lurking is good, you often learn more that way. In my sig line is a link to the online FSMs, carb manual and other rotary related reading. Download whatever you need and study.
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innertwist

iTrader: (3)

Before you spend all the money, check to see that you don't already have an aftermarket fuel pump. Maybe a previous owner installed one and now the fpr is malfunctioning. It would further explain why the pump continues running when the car is off.