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Discussion Starter #1
Just wondering about possible solutions to my hard start. The car is a 74 GTV 2000 which was converted from Spica to Weber before I bought it. The test drive happened on a pre-warmed car whihc made me suspicious but it restarted very well then ! No choke, and no clue because I inherited it like that. Are conversions notorious hard starters ?

Once it starts, the car runs and idles *perfectly* right away - rock solid - maybe a little rich but that's not a huge problem for now. Restarting the same day is no problem at all, it is immediate. However, if the car hasn't run for 48 hours, it *feels* like the carbs are bone dry...and I suspect they are. Is that a common issue ?

I have an old Porsche that will evaporate modern ethanol fuel pretty quickly also, but I can generally have it started in 20 seconds, 2 or 3 attempts worst case while pumping the gas pedal furiously. The Alfa however sounds like it has an electric fuel pump (tic tick tick, so no foot pumping) and will absolutely positively *not* start for 7-8 attempts, over a 60-90 seconds or possibly more depending how nice I feel like being to the starter motor, when it has not been used that day.... I've let the fuel pump tick away for what seems like an eternity (I need to time it, but probably one whole minute) and it won't stop running - I'm not entirely sure it will stop when the carbs are filled so I hesitate to leave it longer....

As I said it seems the bowls are dry... if I crank immediately it doesn't even pretend to start. After 30 seconds of fuel pump, it coughs once and dies. After 60 sec: coughs more, runs one second and dies... Then eventually (couple more attempts) it goes and is immediately *perfect*, as if pretending nothing happened. Curious if this is par for the course with conversions, or if I am missing something...
 

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Many BBers with carbs will tell you "you don't need a choke, just pump the throttle a few times before you turn the key".

Having an electric fuel pump probably doesn't change that...try a few pumps, the worst you can do is flood the motor and have to either clear it thru having the throttle wide open as you hit the starter and hold it open for several seconds...or wait until the excess fuel evaporates.

Others may chime in, but I also must assume that the fact that the pump runs all the time is how it is meant to be with your conversion. Once the float bowls are full and closed off by the needle valve, excess fuel would be returned to the tank via a separate line. Euro-spec cars have mechanical fuel pumps, so don't have a return line.
 

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My car has a Weber conversion. Starting consists of ignition on, electric fuel pump starts, choke pulled out (all the way when it has not been started in more then 5 hours), pump gas twice, start it. Usually starts on first attempt. If it has not been driven for a week, it may take 2 attempts. I need a choke and a pump (or two).
 

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Richard Jemison
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Fuel

A ticking from the pump indicates a magnetic pulse low pressure pump that will run constantly with the ignition on.
Let it run for a minute to fill the carbs and with a pump of the accelerator it should start.

If it is dry "overnight" check the gaskets on the square cover under the two carbs. Maybe screws are loose even. There is no other way fuel can escape other than evaporation.
 

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You need to use a FACET low pressure, high volume electric pump in place of the mechanical. Mount it in back FUSED and close to the tank. Use a pressure regulator, either FISPA FRB 11 or Filter King. Both pump and regulator are available from Centerline. Set fuel pressure at 3# engine idling, or 3.5 # pressure engine off. More pressure will give you problems.
In use, allow the electric pump to FULL THE WEBERS before trying to start. You can tell by listening for a change in pump noise.
 

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Mine need 4 pumps of the gas pedal when I start in the morning, so did my previous Webers.
 

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The car is a 74 GTV 2000 which was converted from Spica to Weber before I bought it.
This is not a common symptom, so it should be fixable.

A few things you didn't tell us:

- You may have vacuum leaks that result in too lean a mixture to allow the cold engine to fire. It would be useful to know whether the conversion done using an Alfa carburetor manifold, or by retaining the Spica manifold and using adapter plates, as that will suggest where to look for the leak.

- Are the enrichening devices (AKA "chokes") hooked up? These are the levers on the intake manifold side of the carbs, typically hidden under the water passage. Again, if these aren't actuated while cold starting, the mixture may be too lean to allow the cold engine to fire.

- How are the carbs jetted? If the slow-running circuit has jets that are too small, the mixture may be too lean to..(well, you get the idea).
 

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As Gordon said, check fuel pressure at the carbs to make sure it's in spec. If it's wrong with the electric pump then the carbs may not fill fully or they'll flood.

Then check that your accelerator pumps are working. Look down the throat with a mirror for a squirt of fuel as the pedal is firmly pumped.

If that's all good it should start with three or four pumps of the pedal then cranking with a little throttle within 2-3 tries.

If it's still hard to start, manually move the cold start levers halfway and see if they help. You shouldn't absolutely need them, but they can help a lot with cold starting even if everything else is set up properly.
 

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The Alfa MECHANICAL pump at the right front bottom of the engine, will take considerable cranking with the starter to fill dry Webers. This is NOT good for the starter. Originally, these cars were driven every day, and fuel levels in the Webers never was low enough to prevent EASY starting as has been discussed above. If you need to crank and crank, the Webers are dry, and more quickly filled with an electric pump, saving the starter.
I have nothing against the Alfa mechanical engine diven pump.
If you are using a SPICA pump to fill the Webers, that's another issue.
 

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If I've followed this thread correctly, you say the starting mechanism is not hooked up? I recommend you do. With this, you can develop a sure fire technique for all conditions.

On my 102 using a FNM 2300 for the first start of the day, or later if it is very cold out, I turn on the key, listening until the pump ticking slows. Then I pull the enriching (start) lever half way out. Then, without touching the accelerator I bump the starter a few compression strokes two or three times. Usually, on the third bump it starts and idles perfectly.

I believe that my DCOM carbs drain overnight into the cylinders, so excess pumping just creates a bit of hydraulic lock and requires much cranking to clear. Hence, no accelerator for starting.

When the car has even a slight bit of warmth to it, pump twice, crank, start.

On a 105/115 engine the carbs aren't angled downward so steeply, so you may not get the drainage into the cylinders. As a result, you may need to pump a few times.

The enrichening/starter system works. Hook it up.
 

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Discussion Starter #13
Ok thanks guys ! Good to know this is not normal... I am also a bit confused about pumping the gas pedal being effective in case of an electric pump... To answer some good suggestions/questions, the choke "pull out" is disabled (won't move at all in my car, I believe it's screwed in position - if I pull hard it moves 2mm and a choke light comes on the dash but it's basically disabled). I recall the seller saying there was no choke installed for the carbs so it was a little iffy to start. So chokes are not hooked up at all.

I have other oldies that start fine without a choke, my problem is not a matter of having to keep the revs up when cold fo ra little while, it's not starting at all, not even pretending to until I let the bowls fill up 60-90 secs, it feels like there just is no fuel...

Basically the Alfa is as hard to start after 48hrs as the Porsches are after 2 weeks, or so... Seems like empty bowls to me, but I struggle with that quick of a loss of gas - maybe closeness of the bowl to the engine ?

I will open them up and check, I'm unfamiliar with those side webers (i have webers son a 912 but they look nothing like these)... but yeah I never flooded it, I don't think I could if I tried! Also even when cold, the car starts GREAT if it's within a few hours of the previous start... No pump, nothing, immediate vrooom, so I'm not sure I need to mess with chokes. Definitely seems (lack of) fuel related. I realize I can answer my own Q by looking at the bowl, I just wanted a baseline from you guys before I tore into stuff with no clue !!! Thanks for providing it !

I'm probably good on vacuum leaks (famous last words) because if anything, it's running too rich overall... I can't quite answer "Alfa carburetor manifold, or Spica manifold using adapter plates" because I didn't do the conversion and never saw each kind before, but I can take pictures tonight!

I will take it to an Alfa pro soon, mostly I wanted to check if a whole 60 secs of fuel pump to fill the bowls was common, sounds like it could be IF my bowls are empty from too much fuel evaporation, so I will check the gaskets and look for possible leaks.. Many thanks !
 

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Does your car have the original gas tank with the fuel discharge from the bottom? If so you should have no problem filling the float bowls. What kind of pump are you using? Where is the filter positioned relative to the pump? Do you have a pressure regulator and what is it set at?

I removed the cold start mechanisms from my current and previous Webers and replaced them with blanking plates. They can leak and I don't need them in South Carolina. My starting procedure is to turn on the ignition, wait about 5 seconds then pump the gas pedal 4 times. The car always starts at the first attempt.
 

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I am also a bit confused about pumping the gas pedal being effective in case of an electric pump...
Type of fuel pump has nothing to do with the driver using his/her right foot to pump the accelerator pedal as a starting (the engine) technique.

These 105 Alfa engines (unless you live in areas of extreme cold) do not need choke and the technique is to, once the carb bowls are fill of fuel, pump the accelerator pedal twice and then turn the ignition key. Yes you need to play with the accelerator pedal to keep them going until warm but it works as the 2 pumps provides the extra fuel in the combustion chamber required for the right mixture for a cold start.

I've never used choke on any Alfa engine actually ... and I've never had cold start issues (hot start yes ... sigh).
Pete
 

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Discussion Starter #16
Yeah that is the odd part about my car. Hard to start, but once it does, it's rock solid at idle despite no choke ;-) I'll start looking at it tonight before I farm this out ;-)
 

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So, you're getting contradictory info here. I'll try to simplify.

Yes, your carbs are likely dry if the car has sat overnight. It can matter which Webers you have, but regardless, pumping the gas pedal before the float bowls fill is wasted energy.

The starting circuit can help. I highly recommend you hook it up. However, like other Weber items, there are adjustments to be made. It will help more in cold climates than warm. Your BB ID does not tell us where you are.

So, click on the key, but do not crank until your fuel pump nearly stops clicking. Then, 3 - 5 pumps on the accelerator and THEN crank.
 

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Discussion Starter #19
Okay... Took a look and the bowls seemed OK after 2 days of not running... I cranked it for giggles, and cough-die. Let it pump 10 seconds and pumped the gas pedal 4 times: it started... Progress... Will look this week end if I don't drive it till then, I want to see if those bowls dry up !

Pic attached for the adapter plate question..
 

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Richard Jemison
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Webers

Look and feel around the bottom under the carbs at the square plate covering the bottom of the fuel bowl below the jet pickups which are not visable from the top. If wet or fuel stained change the gaskets on those two covers.
 
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