Home page
SPONSOR AD

Topic: Hard Start

in Forum: C3 Engines


Hard Start

Posted: 5/31/07 5:59am Message 11 of 16
Former Member
Send PM
Simpsonville, SC - USA
Joined: 1/21/2007
Posts: 85
Vette(s): 1978 25th. Silver Anniversary Edition 350 L-82 Stock

OK, getting better.  Started checking for gas siphoning back to the tank.  Let the car sit over night.  Popped the breather cover and started pumping the carb while watching the gas squirt.  I was only able to get 2 pumps with a little gas squirting.  All pumps after that where dry.  I then started the car and let it run for a minute.  Turned it off, and pumped the carb again.  This time, I was able to get 10 good squirts before it started the fade.  So, I decided to check the fuel filter to see if it was the kind with a built in check valve.  It does not have one.  But, when I went to remove the fuel line.  I noticed the fuel filter nut was loose!  I haven’t noticed any gas leaks but I suppose this could have allowed air in the system.  Tightened the fuel filter nut and let the car sit overnight.  The car started immediately this morning with one pump.  The jury is still out though.  Question, does the fuel pump also have a check valve in it also?




SPONSOR AD:: (Our Sponsors help support C3VR)

Hard Start

Posted: 5/31/07 6:30am Message 12 of 16
Lifetime MemberLifetime Member
Send PM
Oceanside, CA - USA
Joined: 11/19/2003
Posts: 191
Vette(s): 1978 Silver Anniversary model. Original L82 engine, 700r4 trans, edelbrock intake, thorly headers, rack&pinion steering, mono rear and front spring, MSD 6A box
I have a 78 SA with the same problem you are describing.  I have a new Edelbrock Q Jet on mine.  The only thing I have not tried is a new fuel pump.  If you find the fix please post it.


Hard Start

Posted: 5/31/07 7:51am Message 13 of 16
Profile Pic
Lifetime MemberLifetime Member
Send PM
Manteca, CA - USA
Joined: 11/20/2005
Posts: 3623
Vette(s): 1978,two tone,Metalic Rootbeer & gold 1975 L48 4 speed
When you start suspecting the fuel pump on the '78s, before checking the fuel pressure, check the condition of the fuel line couplers just out of the tank. Both my 78s had to be replaced. They were so full of cracks it was a wonder they picked up fuel at all ( I kept one as a conversation piece LOL).If you remove the chrome ring at the gas tank, and the rubber boot, you'll see two lines going off to the right, the larger 3/8" is the pick up. You can easily see if they're cracked. If you have to replace one or more of those ( it is a little tricky ) be sure to replace the restraint that keeps them aligned so they don't wear prematurely from stress. 


Hard Start

Posted: 5/31/07 8:02pm Message 14 of 16
Profile Pic
Lifetime MemberLifetime Member
Moderator
Send PM
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
[QUOTE=bytor]Question, does the fuel pump also have a check valve in it also?[/QUOTE]

Yes...sorta...the pump works by opening/closing the in-out valves...They are basically one-way valves, that only allow flow in one direction. One in, one out.
Not a real technical answer, but...

IF the fuel fitting is loose at the carb, it is conceivable that it could allow an air break in the fuel system, and allow the fuel to drain(siphon) back out of the line from the pump to the carb...


Joel Adams
C3VR Lifetime Member #56    

My Link


(click for Texas-sized view!)
             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

Hard Start

Posted: 6/7/07 6:06am Message 15 of 16
Former Member
Send PM
Simpsonville, SC - USA
Joined: 1/21/2007
Posts: 85
Vette(s): 1978 25th. Silver Anniversary Edition 350 L-82 Stock
Installed a fuel filter with a check valve and that did the trick.  I did check my fuel couplers back on the gas tank.  They have a few cracks but not that bad but I added it to my replace soon list.  Thanks for the tips!! bytor2007-06-07 06:07:05


Hard Start

Posted: 6/7/07 6:27am Message 16 of 16
Profile Pic
Lifetime MemberLifetime Member
Moderator
Send PM
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

Hope that solves it!!!


Joel Adams
C3VR Lifetime Member #56    

My Link


(click for Texas-sized view!)
             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

in Forum: C3 Engines


SPONSOR AD: (Our Sponsors help support C3VR)