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Sat Mar 07, 2015 10:42 am

I've acquired a bit of a fuel system problem. After sitting over night, my Roadster won't start without pouring fuel into the carb. My first thought is that I must have a small leak somewhere in the fuel line between the tank (up front) and my carb. Though I also noticed that the accelerator pump doesn't seem to be squirting fuel into the carb throat either. So apparently the bowl is leaking empty as well?
It has a new Carb, a new Fuel Pump, new Fuel lines to the steel tubing fuel line on both the tank and engine ends, I have also installed a new dial in Fuel Pressure Regulator between the pump and the carb.
Anyone had this same problem in the past? Any suggestions on what is causing it?

Sat Mar 07, 2015 2:14 pm

A6ULdv8 wrote: ..........It has a new Carb, a new Fuel Pump,.........
New Chinese?, I've seen one that had a bad drilling or casting flaw that leaked into the throat and could drain the bowl. Could be the fuel pump leaking into the case as well.
Start by clamping a line between the pump and carb overnight and see if it's still gone dry in the AM, or better yet remove it and see if it's dripping. Also have a good look at the upper gasket on the carb. many have warped lids and don't seal, it's possible it could evaporate overnight I guess.

Sat Mar 07, 2015 5:23 pm

The carb is a Decade so yes a New Chinese. Although when I installed it, it was practically "Plug and play" right out of the box. Very little tweaking to get it purring.

Sun Mar 08, 2015 5:21 am

I would suspect the fuel pump. There are small check valves in it that keep fuel from back flowing. They are nothing more than a thin flap of metal with a keeper holding them over a passage through the pump housing. Could be something in there not allowing them to seal.

Your probably gonna catch some flack by having that fuel filter situated on your distributor cap too... Although everything looks tidy, if that plastic filter ruptures/fails.....you will certainly lose more than your prime.

Sun Mar 08, 2015 6:21 am

The carb bowl should be full of gas and even if there was a check ball issue in the fuel pump, there should be enough gas to start the car with what is in the carb. There is no way that the fuel would get siphoned out of the bowl. SO that being said, I would look at the carb for the problem.

But if you are not getting any squirt, that will make it VERY difficult to start. What you need to do is pop the top off the carb to confirm there is gas. If there is, then I suspect you have a failure of the accel pump (clogged nozzle, bad diaphragm?). If that was the case it would not work at all meaning that once the car is started and you hit the gas pedal, it would bog really badly.

Sun Mar 08, 2015 6:26 am

My bet, carb
Even if you took the fuel lines off for a week, the carb should still be full and should start and run till it ran dry.

Sounds like choke and accel pump problem.

If you pull the top of the carb and it is empty.
Then I would say a casting flaw or syphoning problem into the intake.

Even if the fuel pump is bleeding off, it wont be able to drain the carb back to the tank

Sun Mar 08, 2015 8:02 am

remove the fuel pressure regulator and your problem will go away. Those cheap dial regulators are pure junk.

Sun Mar 08, 2015 9:31 am

Sorry, but that carb isn't worth the box it shipped in. That "Richporter" stuff has gotten some pretty low reviews too.

Sun Mar 08, 2015 7:23 pm

Why on this earth is a fuel pressure regulator needed for a stock carb? Isn't that what a stock mechanical fuel pump manages anyway?

Tue Mar 10, 2015 3:22 am

Thanks for the input anthracitedub I've pretty much ruled out the fuel pump though. And yes, I caught some flack about the placement of that fuel filter when I posted that picture before in a different thread. It was only there temporarily so I could see the fuel flow while I was adjusting and fine tuning the new components. It resides under the car now, down near where the fuel line comes out of the center channel, with a second filter located up front right near the tank.

Hey andk5591, I agree that the bowl should stay full, and that it should be enough gas to start the car. However that doesn't seem to be the case. Once I fill the bowl manually, it seems to work just fine. Doesn't bog down upon acceleration either.

Well MacLeod Willy , there is no choke. Even though the carb came with an automatic attached, I disabled it and wired the choke wide open. Living in Florida it only take a minute to be warmed up.

But vwracerdave, my problems were much worse before I put in the fuel pressure regulator. The pressure was about 3 times what the specs call for, and kept flooding out the engine on deceleration.

Actually Q-Dog, both components worked fabulously right out of the box. I have read both good and bad reviews about most everything. Unless something has become notorious for malfunctioning in a certain way, I tend not to write it off as worthless in general. The carb and distributor has worked well and worked well together for about a year now. This losing the prime situation is something new. The only downside I have found with the RichPorter Distributor/Coil system is when you want to replace the cap and rotor. None of the parts stores that sell the RPT even have a listing for replacement cap. It's much larger in diameter than a Bosch 009 cap. I was finally able to get one through Spectra Premium who has just completed the acquisition of RichPorter Technology. They had a cap and rotor at my door from Canada to Florida in a few days with no cost to me at all.

I don't know why hitest. The pump was putting out somewhere near 7 lbs of pressure and kept flooding out the engine. I installed the regulator, dialing it down to 3 lbs and it ran great after that.

Actually it is still running great once it is running. I've just had to prime it to get it started the last week or so.

Thanks Everyone who replied to my question. At this point, I am letting it set a couple of days and then going to pull the top off the Carb to see if the bowl is completely empty or what. I'll have to take it from there. I'll let you all know what I find when I open her up.

Tue Mar 10, 2015 6:26 am

A6ULdv8 wrote: Well MacLeod Willy , there is no choke. Even though the carb came with an automatic attached, I disabled it and wired the choke wide open. Living in Florida it only take a minute to be warmed up.
.

From what I hear up here is Florida gets winter down there now too. I believe you need to adjust the choke properly. It is there for initial starts even if it is 60F. It will not rob your gas consumption, in fact may even improve it under some conditions.

Take the thing out for a hard run, then shut it down, remove the air filter. After 20/30 seconds look down the venturi with a flashlight. You should see faint white smoke if it is dribbling into the intake hitting the hot intake

Tue Mar 10, 2015 11:12 am

I've had crap in the fuel line between the pump and carb that would clog the inlet, then the line would clear and engine would run, for a while till it clogged again.

Took off the fuel line and heard something hit the ground with a little 'tic', problem went away.

Wed Mar 11, 2015 11:20 am

[quote="MacLeod Willy"] A6ULdv8 wrote: Well MacLeod Willy , From what I hear up here is Florida gets winter down there now too.
Yes we do...Like right now it is 89.1 °F outside. Pretty much been that way all winter too.

Wed Mar 11, 2015 11:23 am

jwold wrote: I've had crap in the fuel line between the pump and carb that would clog the inlet, then the line would clear and engine would run, for a while till it clogged again.

Thing is though, is that it runs great, just losing it's prime. It has to be getting air from somewhere to allow the fuel in the line to bleed back out of the line.

Wed Mar 11, 2015 12:44 pm

[quote="A6ULdv8"] MacLeod Willy wrote: A6ULdv8 wrote: Well MacLeod Willy , From what I hear up here is Florida gets winter down there now too.
Yes we do...Like right now it is 89.1 °F outside. Pretty much been that way all winter too.

That's it..... I'm moving :lol:

Wed Mar 11, 2015 2:07 pm

OK - Stop and think about this....The fuel inlet is at the top of the carb. Gas comes in the needle valve at the top. There is about 3/4" of air between the fuel inlet and the fuel in the bowl. It CAN'T siphon back out.

Wed Mar 11, 2015 2:35 pm

Correct, and even if there was an issue with the lines and they all went dry there's still enough fuel in the float bowl to start it and usually run long enough for the fuel pump to fill everything back up. Now if that hokey regulator is restricting it so badly that the bowl is almost empty all the time and the remains evaporate or escape through a flaw in the carb it could seem almost dry in the AM.

Take the top off the bowl when you shut it down and see how much fuel is in there, then look again in the AM.