JM1981Civic

Hello All,

I own an 81 Civic hatchback w/1.5L motor. My mechanic advised me about 1 month ago that the carburetor was bad. I ordered a rebuilt 3bbl from National Carburetors. It came was bench-tested prior to shipping and then the engine was getting flooded and would run properly. Was told by a 2nd mechanic that the rebuilt carb was bad. Contacted National and told them the story and they offered to rebuild my original carburetor if I'd send it to them, which I did.

After receiving the 2nd rebuild, it was installed and ran good for about 45 minutes. After parking it overnight, it wouldn't turn over the next day. Seems the engine is flooding again. Spark plugs are soaked with Gas.

It's hard for me to believe that both rebuilt carburetors are bad. Can anyone offer some advice as to what else my be the root of the flooding problem if truly not the carbs?

Thanks in advance for sharing your expertise with me.

John

ezone

1) Have you ever owned and driven any automobile with a carb before this?
2) Most carbs need to be tweaked and adjusted once they are attached to a running engine.
3) Does the choke work? Does the pull-off work? Does it open as the engine warms up?
4) Your mechanics: Are they over the age of 50?

Carbs have not been used on any new car in the USA since 1995.
Very few younguns have ANY clue about them primitive carburetor thingamajigs.

JM1981Civic

Yes to all questions received. If possible, looking for advice on possible causes excluding the carburetor. Anyone have any other advice to offer? Would be much appreciated.

ezone

Would that be a CVCC car?



The carb meters all fuel that enters the combustion chambers.
If the carb is truly not at fault, then it should be a matter of any little engine problem that interferes with or doesn't allow the fuel to be burned properly.....

...or operator error.

What makes you think it is not a carb problem?


Carb rebuilding is a lost art.
A) Few people really did it well back when everyone did it, and there aren't many of those people left.
B) Most just took the carb apart and cleaned it and reassembled it however it came apart without being able to correct any problems.
C) Many were hacks. Plenty of the carbs on the road were never again "right" once a hack got their grubby mitts on it. You had to take it to 'A' if you ever had any hope of it being right again.

Really, the biggest problem I see with (younger) people trying to drive (old) carbureted cars these days is the vast majority simply have not been taught/do not know/don't WANT to know anything about basic engine operating needs under various conditions, how to work it, set the choke, don't pump the pedal without knowing what happens, or what to do when things don't go as planned--use the pedal, dechoke and clear-flood modes.

IMO, Fuel Injection has removed the need for basic knowledge of engine operation. People expect to twist the key and have everything magically work. Panic when it doesn't.

/rant


Ok...
Causes of appearing flooded other than the carb itself? Off the top of my head:
vacuum hoses connected wrong?
problems with external carb controls? (IDK what is on it)
breather preheat tube wrong/missing/inoperative T.A.C.
Loss of spark/weak/insufficient
Low compression (valve adjustment, rings, Incorrect cam timing, etc.)
Incorrect ignition timing
Short trips
plug fouling
How about coolant on the plugs?
Something other than fresh gasoline in the tank

Probably more.

iim1rmg

When you say:

After parking it overnight, it wouldn't turn over the next day.

Did you really mean it would not turn over (won't crank) or that it wouldn't fire.

If it would not turn, it takes a lot of gasoline to cause it to hydraulic-lock, then gas is running straight from the carb into the intake manifold while the engine is setting. That is not a good thing.

There are a bunch of vacuum lines and sensors that are used by the carb.

There should be a vacuum schematic attached under the hood. The first thing I would do, assuming that you meant it won't fire, is verify that you have spark. Assuming that you do, the next thing is take a digital picture of the vacuum schematic, blow it up and print it on an 8 x 10 where it is usable, then check every vacuum line and make sure they are all connected to the right place, and check them off on your print out.

Some of them go through metal manifolds, so sometimes these are easiest to check by disconnecting the lines at both ends, attaching a piece of long vacuum line or a surgical tube to one end and blowing in it while feeling to see if the air is coming out the other end. If you verify that much, and have a vacuum pump, you can plug one end, put vacuum on the other, and make sure there are no leaks in the metal manifold (sometimes they will vibrate against something and wear or fret through in a spot hard to see.)

I had a couple of vacuum lines switched where they connect to a manifold on an '87 1.5 and everything ran great until I turned on the air conditioner and then the engine would die.

Like Ezone said, not many folks can really rebuild a carb any more. Some don't even know when a core is not rebuildable, so I would not rule out a bad carb.

On the other hand, two "rebuilt" carbs did not fix the problem, so... make sure it isn't something else. Vacuum leaks play havoc. They are hard to find and sometimes yield intermittant (or so it seems) problems. After changing the carb, the first thing I would check is every vacuum line you disconnected, and next, every vacuum line that is close to one you disconnected.

Did you get the wiring harnesses (all of them) reconnected? On an 87 there ate three electrical connections - one single wire and two plugs if I remember correctly (maybe that's the 88 Nova/corolla).

If all the vacuum and electrical connections check out, check your manual for setting the choke.

How are you starting it?

The procedure for these is:

When cold, push the accelerator once all the way to the floor and let up- that sets the choke for the current ambient temperature. Then leave the accelerator pedal alone, and turn the engine over. It should fire right up, run sort of fast for a couple of minutes, then kick down to a normal idle.

If you just get in and crank it, like an injected engine, the choke may be too far closed and the engine will just flood.