Register now to get rid of these ads!

Technical Need gas

Discussion in 'The Hokey Ass Message Board' started by pull toy, Jan 3, 2020.

  1. pull toy
    Joined: Aug 22, 2013
    Posts: 55

    pull toy
    Member

    Gonna ask a question that I know is not new but here goes. My Street Rod is powered by a 454 bb Chevy. The carb is by Edelbrock model 1404 [new] the fuel pump is also Edelbrock model 1721 also new. The problem is after setting for two days its a crank-crank situation to get the engine to light off. After first crank up it's fine for a day or maybe two. I've talked to Edelbrock Tech and they blame it all on gasoline evaporation. Adding a low psi electric fuel pump between tank and manual pump, to fill the carb, will not work since manual pump is diaphragm operated and not able to push fuel through it. What is my best solution economically and safely short of trashing the entire carb setup and going all EFI. Fuel tank is in the very rear of bed approx 11 feet from manual fuel pump.
     
  2. onetrickpony
    Joined: Sep 21, 2010
    Posts: 437

    onetrickpony
    Member
    from Texas

    Have you pumped the throttle and watched to see if the carb was really dry? My old truck does not have that problem, even during the hottest part of the summer. One pump of the pedal to give it a squirt of gas and set the choke and it fires right up. But it's a Holley.
     
    chryslerfan55 likes this.
  3. big john d
    Joined: Nov 24, 2011
    Posts: 154

    big john d
    Member
    from ma

    my off topic car uses a 4 psi electric pump and it moves fuel to the carb through a holley mech pump no problem
     
    seb fontana and olscrounger like this.
  4. OFT
    Joined: Jun 1, 2005
    Posts: 536

    OFT
    Member

    Could you bypass the mechanical pump and use only electric? I've used that set up for close to 40 years in the OFT in avatar. Tanks are just in front of dually wheels in photo. In past have run BBC with blower, SBC with blower, BBC without blower and SBC without blower.
     
    Atwater Mike and chryslerfan55 like this.
    Register now to get rid of these ads!

  5. Mopar Tony
    Joined: Jun 11, 2019
    Posts: 263

    Mopar Tony
    Member
    from SE Iowa

    I'm assuming you are pumping the pedal while trying to start it?
     
    clem likes this.
  6. PhilA
    Joined: Sep 6, 2018
    Posts: 689

    PhilA
    Member

    I have a small off-brand impeller type electric pump that draws through fine when it's not spinning- I have it hooked up to the starter button. Put the shifter into gear, push button to prime the pump then into N to get it to fire up.

    My only concern there is that your motor would draw significantly more gas than mine in a full-throttle situation... the flow may be impeded too much via the electric pump. If it is vaporization could you not make a loop system, pump draws up to a pressure regulator that dumps unused fuel back to the tank and keeps cooler gasoline from the tank circulated round, leaving the only "static" flow from the regulator to the float bowl?

    Just thinking out loud

    --Phil
     
    chryslerfan55 likes this.
  7. Happydaze
    Joined: Aug 21, 2009
    Posts: 947

    Happydaze
    ALLIANCE MEMBER

    Subscribed. I have exactly the same issue which I can live with but would prefer not to if the fix was simple. A phenolic spacer made no difference for me. Admittedly I've never checked to see if there's any squirt from the accelerator pump when it's sat for a while. I'm using a stock Chevy fuel pump but my understanding is that there's a non return valve in there, but it's not as if the fuel in the bowl can syphon back to the tank anyway. Stumped and participating!

    Chris
     
    chryslerfan55 likes this.
  8. pull toy
    Joined: Aug 22, 2013
    Posts: 55

    pull toy
    Member

    Thanks so much for the input. Yes I do pump the quick jet but carb is always dry at first start up. It seems my best bet may be as Big John d said to change out the Edelbrock mechanical pump with a pump that would allow flow through and add a small psi electrical pump next to the fuel tank and re-plum between the two pumps with a hard line. All I would need then is a push and hold switch to run the electrical pump for a short fuel line power up time. The trick will be to identify the right flow through mechanical fuel pump. To run an all electrical fuel delivery system would work fine if a safety cut-off switch was added along with a fuel pressure regulator and a hard fuel line, since that Edelbrock carb doesn't like anything over 6 psi. Happy New Year to each of you and God bless.
     
    chryslerfan55 likes this.
  9. seb fontana
    Joined: Sep 1, 2005
    Posts: 6,537

    seb fontana
    Member
    from ct

    Put a check valve between in and out port of electric pump, look up carter rotary electric punp installation instructions, page 5 or so..Works for all electric pumps..
     
    chryslerfan55 likes this.
  10. hotrodjack33
    Joined: Aug 19, 2019
    Posts: 1,057

    hotrodjack33
    ALLIANCE MEMBER

    I found an easy fix for this same hard starting problem on my old '32. It had a 302 Ford, stock mech fuel pump, Edelbrock 1406 and inline filter between the tank and fuel pump.
    I added a second fuel filter (clear see-through type) between the fuel pump and the carb. It seemed to hold enough gas to start the car and I think it prevented any carb leak-down.
     
    chryslerfan55 and clem like this.
  11. ...have had that same problem, this new gas evaps so quickly, I usually just gave it a sip of primer gas in the carb, starts rite up then, runs a lil rough til carb fills, then no problem.
    hotrodjack mite have a solution there, worth a try.
     
  12. town sedan
    Joined: Aug 18, 2011
    Posts: 1,290

    town sedan
    ALLIANCE MEMBER

    Maybe it's the "gas" its self.
    Do you have ethanol free gasoline available and have you tried it yet?
    -Dave
     
    chryslerfan55 likes this.
  13. blowby
    Joined: Dec 27, 2012
    Posts: 6,744

    blowby
    Member
    from Nicasio Ca

    Same issue on all 3 of my mechanical pump carbureted shitpiles. Qjet, Holley DP and 97s, so not the carbs. I took an empty quart of oil, poked a hole in the cap, pushed a foot of vacuum line through and that's my primer gas. Put a hole in the air cleaner lid with a push in plug.
     
    chryslerfan55 likes this.
  14. My ‘30 Ford roadster with SBC, 3 deuces had the same problem after setting for a few days. I was also thinking of adding one of those small low pressure electric fuel pumps, K&N, that I could turn on to prime the system. Wondered about fuel restriction when turned off. Interesting discussion.


    Sent from my iPhone using The H.A.M.B. mobile app
     
    chryslerfan55 likes this.
  15. flynbrian48
    Joined: Mar 10, 2008
    Posts: 6,480

    flynbrian48
    Member

    I had an issue with my '34, 283, Offy 360 dual quad intake with the little 500 CFM E carbs, percolating the fuel in the bowls when hot, and hard to start after a few minutes because it'd be flooded from fuel in the intake plenum. After a couple of days, that too would have evaporated and then it'd do what yours is doing, which is quite a bit of cranking before it'd fire. All that was fixed with a couple of spacers I made from some 1/4" Lexan between the carbs and the intake. I don't know if this could be what yours is doing, but a spacer won't hurt anything. Gas with ethanol in it is the culprit, it has a lower boiling point. My intake was a contributor, with it's very low profile, held heat more than a higher based intake would. So I was told anyway...
     
    chryslerfan55 likes this.
  16. Moon50F3
    Joined: Sep 18, 2014
    Posts: 214

    Moon50F3
    ALLIANCE MEMBER
    from Mesa, AZ

    This is an interesting discussion. I have a 1404 on the SBC in my truck. Mechanical pump and same situation as the OP. It will fire up the next day or two after running it without even touching the pedal, but if I don’t drive it till next week, there’s a lot of cranking and some pedal pumping to get it started.
    BTW, I run the ethanol free gas.
     
    chryslerfan55 likes this.
  17. Hdonlybob
    Joined: Feb 1, 2005
    Posts: 3,896

    Hdonlybob
    Member

    Don't mean to pile on, but same situation here with m 283. Shut off warm and sit for ~1/2 hour or so, and flooded...sit a week and crank a lot..
    May try that spacer idea..
    I have a high rev starter, so not really a problem.
     
  18. dirty old man
    Joined: Feb 2, 2008
    Posts: 8,589

    dirty old man
    ALLIANCE MEMBER

    When I built BGII, my Hiboy roadster, SBC powered, I had planned to run a mech. pump.
    But when I went to drop engine in, I discovered that because of a pinched P&J '32 repro frame with "A" frt. cross member, the pump wouldn't clear the frame without notching the frame.
    So I installed a Carter elec. low pressure high volume #4070 pump and my Edel 2X4 setup accepts it fine without a regulator, pressure readings approx. 5 psi.
    After sitting idle for even weeks, all I do is turn on switch, listen for sound of pump to change, which tells me pressure is up, slowly depress and release throttle, hit the starter, and it usually fires before it makes more than 2 revolutions.
    This is using premium 10% ethanol and Stabil 360* additive at label prescribed mix.
     
    chryslerfan55 likes this.
  19. pull toy
    Joined: Aug 22, 2013
    Posts: 55

    pull toy
    Member

    I do have a micro filter, screwed into carb as a final filter , I just don't see how gas could evaporate back between carb and pump with no open air exposure.
     
    chryslerfan55 likes this.
  20. pull toy
    Joined: Aug 22, 2013
    Posts: 55

    pull toy
    Member

    Non ethanol is all I use plus a good splash of Seafoam.
     
    chryslerfan55 and town sedan like this.
  21. pull toy
    Joined: Aug 22, 2013
    Posts: 55

    pull toy
    Member

     
    chryslerfan55 likes this.
  22. pull toy
    Joined: Aug 22, 2013
    Posts: 55

    pull toy
    Member

    So you just hard line between rear mounted elec pump and carb no regulator. power wired through ignition switch with a safety oil pressure cut off switch, block off the mech pump port. Sounds workable my question is does the elec pump cycle or does it run continuously? Probable either way it does not matter but a high quality pump would be required for dependability since in my case in this coe engine requires major dismantling, seat, carpet,floorboard & engine cover for access. I confess some of my concerns is sealing the engine compartment up and running without quick access. I have complete confidence in the mech fuel pump because of it's dependable history. I have crossed every tee and dotted every eye trying to get this thing right and now gasoline is gone to pot..
     
    chryslerfan55 likes this.
  23. hotrodjack33
    Joined: Aug 19, 2019
    Posts: 1,057

    hotrodjack33
    ALLIANCE MEMBER

    With the large filter between the pump and the carb, it would hold enough gas to fire the car and get the mech fuel pump going to keep it running went from 15-20 revs to start to 3-4.

    Another thing to consider are any rubber hoses or rubber connecters and hose claps. I've seen rubber hoses and claps that were fluid-tight (no leaks) but were not air-tight.

    Shooting in the dark on this one...
    Is it possible, with the carb sitting higher than your gas tank pick-up, that there could be some kind of siphoning going on? With the car shut off and no more fuel pressure, is it possible to slowly let air in the jets and start a slow siphon of the fuel bowl...and perhaps all the way to the tank? This scenario could also happen with a porous rubber hose or loose clamp. Just a thought.
     
    chryslerfan55 likes this.
  24. I have a 750 Edelbrock on my '32 with an Edelbrock 110 gph mechanical fuel pump.

    I installed a boat tank hand pump in line next to the tank for those dry starts, but I found out the only time I need it is when I run out of gas or work on the carb. The mechanical pump draws through the hand pump without issue. ;)
     
    chryslerfan55 likes this.
  25. pull toy
    Joined: Aug 22, 2013
    Posts: 55

    pull toy
    Member

    First thing I'm going to do is add a check valve in rubber line north of the mech fuel pump to be sure no drain back of fuel to tank exist That way if pump becomes dry it will have to be evaporation.
     
    chryslerfan55 and hotrodjack33 like this.
  26. I have solved the evaporation problem that occurs if rod sits for a few days.
    I have sbc with GM mechanical pump. Carter electric pump on frame near tank. Toggle switch on electric pump.
    To cold start I switch on electric pump. Wait 5 to 10 seconds. Crank and gently pump pedal. Starts with 5 to 10 seconds of cranking. Switch electric pump off. Done.

    Phil
     
    Last edited: Jan 5, 2020
    chryslerfan55 likes this.
  27. Hot start flooding issue solved. Quarter inch phenolic spacer under carb. Do not touch pedal while cranking. Fires right off.

    Phil
     
  28. hotrodjack33
    Joined: Aug 19, 2019
    Posts: 1,057

    hotrodjack33
    ALLIANCE MEMBER

    I think your idea of a check valve between the carb and fuel pump might be the best solution. Let us know how it works out
     
  29. pull toy
    Joined: Aug 22, 2013
    Posts: 55

    pull toy
    Member

    Thanks for all the input, I'll post any progress results
     
  30. lo-buk
    Joined: Nov 11, 2006
    Posts: 280

    lo-buk
    Member
    from kcmo

    I use fuel filters that have check valves built in so fuel will not siphon back to the tank. Works good for me.
     
    chryslerfan55 and Mopar Tony like this.

Share This Page

Register now to get rid of these ads!

Archive

Copyright © 1995-2020 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.