car stalls randomly

[monzacoupe]

So remove it even though the canister is long gone?

Rick

[heinz057]

yes

[cjbiagi]

I thought the canister was connected to a vacuum port? Isn't that how it purges the fumes from the charcoal?

[marco_1978_spyder]

I thought the canister was connected to a vacuum port? Isn't that how it purges the fumes from the charcoal?

Thats true..

Now that's got me thinking , with the vent totally capped off.. imagine trying to fill a bottle or any closed space with a liquid, but without anywhere for the air to escape..

That could be the culprit right there...

[cjbiagi]

My point is that I believe that while the port on the carb is for a "vent connection", it's still actually a vacuum port. Running it unplugged could just cause a vacuum leak. Pretty much any port on a carb is vacuum, some ported and some full time. I am not real familiar with that carb but that just seems to make sense to me.

[marco_1978_spyder]

Clyde that port is just a vent..

To fill a chamber with a liquid there has to be a way for air to escape.

Positive vacuum for the canister was provided by the normal / familiar vacuum ports on the carb. via another hose.

With that capped off, fuel my not be able to enter the carb bowl...Or.. fuel might be being pushed out of the top vent tube (seen in the photo, and dumping into the engine stalling it out with too much gas..

[cjbiagi]

OK, thanks for clearing that up.

[monzacoupe]

First of all, thanks for the help so far. I had a chance to get a pressure guage onto the fuel line at the carb and it read Zero, nada, zip. I pulled the line from the exit point of my fuel pump and turned on the car. Pump was pumping nothing but air. I figure that the location of the fuel pump is the problem(outside and above the tank) and it's just a quick fix to put the damned pump where it belongs.

Rick

p.s. Now just shopping around for a good pump cheaper than $90

[hammerdown7]

You can probably adapt a 4 cylinder Fiero fuel pump and it should be much less expensive. Don't get the 6 cylinder one because it operates at a much higher pressure.

Dick

[cjbiagi]

No need to reinvent the wheel here. Dropping the tank is no big deal and you can just install a factory style pump.

[hammerdown7]

Here's a Delco pump for $45 shipped. There are cheaper ones out there but who knows where they were made. This is for an '85 Fiero. Physically similar to h-body, may have to adapt wiring. I know a number of Cosworth owners that have used the 6 cylinder model which is the higher fuel pressure model, too high for a carbureted application. I'll see if Chuck will post what he had to do here. http://www.ebay.com/itm/ACDELCO-EP386-E ... 1129wt_931

Dick

[monzacoupe]

rockauto has the f
least expensive OE part will be going through them I think.

Rick

[monzajer]

Don't wanna go against the grain here, but I have had an outside fuel pump, in the tank area, for quite some time without any problems. Albeit the car has been sitting for several years now, but when I did have it running I can assure you that I played hard, hammering the gas many a time and without any stalling what-so-ever.

I am not trying to say that is not the problem, it most certainly could be. All I am saying is, it may not be the ONLY problem. If you have a good fuel pump, even outside the tank, and within parameters fuel pressure there may something else that is the nasty little culprit.

A buddy of mine recently found out the fuel pickup in the tank of his 70 Chevelle was bent in a "V" shape. The mechanic called him and said "I'm surprised it got gas at all". It didn't run bad before, he was having a gas gauge problem, that they thought was due to the sending unit. They replaced the pickup/sending unit and, voila, the car runs great.

I reread the thread and didn't see where you said you have had the tank down, the pick-up/sending unit out and checked for obstructions or damage. Sometimes the "sock" disintegrates and that crap will clog the pickup. Or there is some other problem not allowing the fuel to flow. Or the sock has rotted and sediment(dirt and other debris-as Marco said) has found its way into the pickup tube. Maybe disconnect the tube somewhere near the tank and blow air through the line backwards toward the tank to see if anything is dislodged.

Has the car sat for a long while? Is there any reason to think there is any kind of old gas sludge build up in the line that may have became loose and lodge itself somewhere else?

Another thing, is the fuel line run anywhere near the exhaust or any other heat source? I know you have tested the fuel pressure without the car running---cold check---and got a ZERO reading, but be sure that once you "think" you have it solved it may show up and throw you off. Just trying to cover all bridges here.

I, for one, am very curious as to what you find.

Good luck. These types of things can drive one nuts tryin to find the gremlin.

cheers, jer

[cjbiagi]

Jer, there are a lot of different types and brands of pumps and some may indeed work well mounted outside the tank. However, there are a lot of variables involved here. Some pumps are self priming and others are not, they need some head pressure by having them mounted lower where fuel can naturally flow into it. I agree 100% that no matter what the tank should be dropped and inspected for any issues, that's where it all starts from so it just makes sense to look there and see what's going on.

[monzabug350]

You might want to pull the old pump and check the filter/sock on the pickup.Had a neighbor that owned a Vega years ago and had the same problem.Went through all the checks and finally found the filter/sock on the pickup would collapse and starve the carb.Replaced it and problem solved.Just a thought.