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Solving the evaporation problem when our cars sit for a while between starts.

I had the same problem as mine sits for a few weeks sometimes between runs, so I just throw a capful of fuel down each carby and she fires right up straight away...
 
I simply prime the float bowls through the vents with a plastic bottle and she fires right up. Works every time.
i7grU.jpg
 
Yep, use a primer bottle on both mine.
Would take a little work to set-up a boost pump, push the switch a few seconds, and go. (Those airplane boost pumps service a one inch fuel hose!)
 
My recently installed :lowdown: Carter M6903 mech fuel pump was my solution for long cranking periods to fill the 3x2 Holley carbs. I just completely disassembled all 3 carbs after the car sat for a few months. Put them all back together and within <15 sec vaROOM.
 
Hi Guys, I realise this is an old thread, but I thought Id let you know how I solved the fuel evaporation problem which as most of you know is the only problem Ive ever encountered with using Edelbrock Performer or the AVS800 I have on my R/T440. i presently own 3 x cars with Edelbrock carbs and this mod Ive done on 2 of them because the latest conversion I did on my 1990 Camaro from TBI to Carb didn't require priming because Im using the existing electric In-tank pump with a return regulator, so no need on that one. On both my 85 Z28 and my 67 Dodge Coronet R/T440 Ive fitted a Marine Dept approved 3/8" Mercruiser Fuel Priming Bulb fitted for easy access just prior to my Mechanical Fuel Lift Pump on both cars. Also I have fitted 0-15psi Liquid Filled pressure gauges between the Lift Pump and the Carbs. These conversions have been on the cars now since 2011 and have worked perfectly. The standard procedure I use on my cars before starting is to lift the hood, do a visual check all over for leaks anywhere, check the drive belts... and all fluid levels. Then I simply lean down and squeeze the Primer Bulb maybe 3-4 times until I see 5 psi on the gauge then I stop pumping all the while watching the gauge... if the gauge maintains that 5psi or drops to maybe 4psi, then you know the bowl(s) are full and ready. If once you stop priming the pressure on the gauge drops away you know its still not full and you can gently continue squeezing until the gauge holds steady at 5psi. Caution, yes theres always a caution... experience has taught me that simply squeezing merrily away until a positive/solid resistance is felt on the primer bulb.... will actually overpower the float needle and flood the bowl(s) these primer bulbs are very efficient at transferring liquids so a gentle touch is all thats required. In saying all the above, Ive only ever had to prime the system either if the car has been sitting for more than 1-2 days after a hot run especially during Summertime runs... or after sitting unused for an extended period like during the Winter months. Another important benefit of having such a mod is Instant Starting everytime... your Starter Motor and Battery will love you for it

Marine Fuel Primer Bulb 3:8" (Mercriuser).png
 
WarrickS said:
Hi Guys, I realise this is an old thread, but I thought Id let you know how I solved the fuel evaporation problem which as most of you know is the only problem Ive ever encountered with using Edelbrock Performer or the AVS800 I have on my R/T440. i presently own 3 x cars with Edelbrock carbs and this mod Ive done on 2 of them because the latest conversion I did on my 1990 Camaro from TBI to Carb didn't require priming because Im using the existing electric In-tank pump with a return regulator, so no need on that one. On both my 85 Z28 and my 67 Dodge Coronet R/T440 Ive fitted a Marine Dept approved 3/8" Mercruiser Fuel Priming Bulb fitted for easy access just prior to my Mechanical Fuel Lift Pump on both cars. Also I have fitted 0-15psi Liquid Filled pressure gauges between the Lift Pump and the Carbs. These conversions have been on the cars now since 2011 and have worked perfectly. The standard procedure I use on my cars before starting is to lift the hood, do a visual check all over for leaks anywhere, check the drive belts... and all fluid levels. Then I simply lean down and squeeze the Primer Bulb maybe 3-4 times until I see 5 psi on the gauge then I stop pumping all the while watching the gauge... if the gauge maintains that 5psi or drops to maybe 4psi, then you know the bowl(s) are full and ready. If once you stop priming the pressure on the gauge drops away you know its still not full and you can gently continue squeezing until the gauge holds steady at 5psi. Caution, yes theres always a caution... experience has taught me that simply squeezing merrily away until a positive/solid resistance is felt on the primer bulb.... will actually overpower the float needle and flood the bowl(s) these primer bulbs are very efficient at transferring liquids so a gentle touch is all thats required. In saying all the above, Ive only ever had to prime the system either if the car has been sitting for more than 1-2 days after a hot run especially during Summertime runs... or after sitting unused for an extended period like during the Winter months. Another important benefit of having such a mod is Instant Starting everytime... your Starter Motor and Battery will love you for it

View attachment 1062582
Click to expand...
Priming bulb. Great idea! Might be a little dangerous.
 
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How well is it standing up to under hood heat ?
 
Darter6 said:
How well is it standing up to under hood heat ?
Click to expand...
We were having that discussion over at FABO. I like the electric pump on a momentary push button switch better.
 
Centerline said:
This is kind of long, so please bare with me.....

I've been doing a lot of reading on this subject and I have a solution that works... at least for me. The 440 in my '64 Polara sits sometimes for a couple weeks or more between starts and cranking the thing for what seems like forever is getting old. So I decided to supplement my mechanical fuel system with an electric pump just for priming the carb. I figured I'd share this mod with the forum just in case anyone else wants to use this method to solve the evaporation problem with today's crappy fuels.

I took a look at a lot of small electric pumps and decided on the Airtex E8090. Its an inexpensive pump (around $35) and puts out 7+ psi which I figured was enough to supply my Holley 750 with enough fuel to fill the bowls in just a few seconds of operation.

One of the things I read was that some electric pumps will not allow fuel to flow through them when they are not operating. This was a primary requirement and was the main reason I chose the Airtex pump. After speaking with their tech people they assured me it would allow the mechanical pump to pull fuel through it when it was off, and they were correct. It does. My mechanical pump actually puts out 7 psi pulling fuel through this pump.

Now I know what some of you are saying. You can't push fuel through a mechanical pump, but you can. Mechanical pumps have a mechanically operated bellows and two one way "reed" type valves. When the cam lobe puts pressure on the fuel pump lever it pushes the bellows and creates a vacuum in the pump which opens the one way valve on the "tank" side of the pump and sucks fuel into the pump chamber. When the cam rotates and releases the lever a spring above the bellows pushes the bellows back down and forces the tank side valve closed while at the same time forcing the carb side valve open and pushing the fuel through that valve up to the carb. A pretty simple mechanical setup really. So it should be easy to see why an electric pump mounted near the tank should be able to provide enough pressure to force open the tank side valve in the pump, fill the pump chamber and also force the carb side valve open allowing fuel to flow to the carb. And, this is exactly what happens.

There is one catch however..... If your mechanical pump bellows fails there is the possibility you could pump raw gas into your oil pan. Not a good thing. However, this is highly unlikely if your pump is in good condition and you're only using the electrical pump to prime the carb before starting the engine.

One more thing about electric pumps. A lot of people bitch about these small inexpensive pumps and say they don't last long. In most cases these people didn't follow the directions and either installed the pump in the wrong location or just installed it incorrectly. My Airtex pump stated that it needs to be installed as close to the tank as possible.... and for good reason. These pumps push fuel much better than pulling it. The directions also stated the outlet needs to be slightly higher than the inlet. Why they want you to do this I don't know but I'm not about to second guess the engineers who designed this product so that's exactly what I did when I installed mine.

First thing I did was to install a fuel pressure gauge so I could tell what kind of pressure the electric pump would put out while pushing fuel through the mechanical pump. The answer was 6-7 psi. More than enough needed.

View attachment 731777

The pump was installed just above the right side shock mount. You can see the outlet is higher than the inlet. Plus I also installed a filter between the pump and the tank as recommended by Airtex. If that cross-member looks a little different than yours its because I added a 2x2 .120 wall square steel cross-member between the frame rails to strengthen that area because I'm running air shocks.... but that's another story.

View attachment 731778

To make sure there was no way I could accidentally leave the pump on I mounted a spring loaded toggle switch under the dash so you have to physically hold it in the "ON" position for it to run. This way you don't have to worry about the pump running if the car is in an accident, rolls over or something else catastrophic happens.

So, does this really work? You bet it does. After sitting for almost a month I activated the electric pump for about 15 seconds and had 6 psi of pressure at the carb. I let it run for another 10 seconds to fill the bowls in the carb and then shut it off. Turned the ignition switch and it started right up. The mechanical pump was providing the carb with 6-7 psi while pulling fuel through the Airtex pump so...... Problem solved.
Click to expand...
Right foot.
 
Bird and Bee hadn't been started since the last cruise mid October. Friday/Saturday I started both. Bee (Holley), mechanical choke on, one tap of the pedal, crank and run. Bird with it's OE Carter, that I have never touched a screw on in 31 years, crank engine over for a few cranks, stop, crank again with 2 pedal taps and runs.
 
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I chose the Carter P60430 pump for my 65 318 poly 2 Bbl. I mounted a momentary push button switch on the bottom edge of the dash wired ignition hot to operate.
Mike
IMG_2495.JPG
 
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493 Mike said:
Yes. That's the one. Did yours have the 5/16" inlet with a 3/8" outlet? I wonder why that is? Chinese thing?
Mike
Click to expand...
I haven't got one yet. I bet it would take care of the short hot soak hard start as well. You know, after a drive you shut it off and restart it in a half hour in front of your buddies and it won't start without cranking on it for a min. or two. LOL It act's like it's flooded but it's not. Vapor lock I am guessing. Push the button and fill the carb with gas and fire her up.
 
So has any one put a fuel check valve in the line at the inlet of the carb. We use to do that back in the day. Never had a dry carb. One tap on the accelerator pedal to close the choke and off it went. But good info thanks for the reading material.
 
khryslerkid said:
In a way, I like to crank the engine several times for pre-oiling. My engine starts so quick when the carbs are full. Useing E-free most of the time, there's always gas there waiting to be fired off. I won't pump the pedal or use the choke for a few cranks just to get the oil up. Then two pumps with the choke and bam, she's running.

I get the electric fuel pump idea for the ethanol fuel and how quick it evaporates especially when the engine is hot. Then when it sits for a period of time it evaporates also.
Click to expand...
I know you know there are better ways do any use a pre oiler now a days?
 
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