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Topic: No Start 74 L48

in Forum: C3 General Discussion


No Start 74 L48

Posted: 11/21/12 3:37pm Message 1 of 4
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Middle Island, NY - USA
Joined: 8/25/2009
Posts: 28
Vette(s): 1974 Chevrolet Corvette Stingray Coupe mille miglia red - black interior 1 of 12,346 4-spds. of 37,503 '74 production production date: 12-'73 L48 350 4 bbl. V8 - dual exhaust M20 4-spd. manual a/c, p/b, p/s, am/fm. rear def.

Help. 74 L48 4-spd was running fine since I bought it 3 years ago. but sat this year. was idling rough lately when I would start it - now will only start when gas is poured in carb. I don't think carb is getting gas. it has a Holley  with bronze filter (haven't changed gas filter yet.) I believe it's a Q-Jet replacement Holley Economaster 4360 -
sprayed carb with Gumout. Some water pooled water might've dripped into tank. drain was clogged. added 2 gallons and dry gas.
I bought a Q-Jet - rebuilt, numbers matching (74 L48 4-spd) with mounting gasket a couple of years ago still in the box. Today ordered the long mounting bolts (not used on the Holley) Everything else looks original (solenoid, etc,)
I'd like to get it running without changing the carb, but it seems like Holley has to come off anyway
float? accelerator pump? at fault.. didn't test fuel pump. Any suggestions or tips on Holley fix or installing the Q-Jet. Which way?
I miss you guys from '10 Carlisle. I'm planning on attending Carlisle in 2013!! Happy Thanksgiving.























|UPDATED|11/21/2012 3:37:18 PM (AZT)|/UPDATED|



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Re: No Start 74 L48

Posted: 11/21/12 10:31am Message 2 of 4
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20229
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
Well...it sure sounds like a fuel problem. Could be one or more of several things, starting with the "sock"(filter) on the end of the fuel pickup in the tank, then the fuel pump, then the carb filter.
Of course...it could also simply be out of fuel...LOL

If you remove the fuel line from the sender unit on the bottom of the tank, and no fuel comes out, that could mean the sock/filter is clogged, or the fuel level in the tank is low.

I wouldn't be to quick to condemn the carb just yet...even tho I despise Holleys on street cars. I would concentrate on verifying the fuel level first, then start at the rear of the car and work my way forward to see why  there is no fuel at the carb. Thumbs Up


|UPDATED|11/21/2012 10:31:51 AM (AZT)|/UPDATED|



Joel Adams
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Re: No Start 74 L48

Posted: 11/21/12 3:29pm Message 3 of 4
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Former Member
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Middle Island, NY - USA
Joined: 8/25/2009
Posts: 28
Vette(s): 1974 Chevrolet Corvette Stingray Coupe mille miglia red - black interior 1 of 12,346 4-spds. of 37,503 '74 production production date: 12-'73 L48 350 4 bbl. V8 - dual exhaust M20 4-spd. manual a/c, p/b, p/s, am/fm. rear def.
Thanks. It's the opposite of what I did. lol. I sprayed the carb with Gumout again, changed the bronze filter. (Iread these clog) There is bit of fuel now squirting in I think - I hear something (but don't see it). Doesn't start still. poured some gas in carb twice , a sputter the first time, but no start. Please explain how to check the sock. I was going to drain the tank next (water?) and refill with 4 gallons.  There might be about 3 gallons in there. I had added 2.













|UPDATED|11/21/2012 3:29:59 PM (AZT)|/UPDATED|



Re: No Start 74 L48

Posted: 11/21/12 8:13pm Message 4 of 4
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Rochester, NY - USA
Joined: 6/12/2012
Posts: 95
Vette(s): 1980 L- 82 fully restored and upgraded.
Go to auto zone or the like and get a vaccum and pressure gauge and test that fuel pump and use the vac gauge to properly adjust the carb .. 


copy and paste 
http://www.autozone.com/autozone/accessories/Actron-3-1-2-in-face-display-0-30-in-vacuum-and-0-10-PSI-pressure-tester-kit/_/N-26ki?itemIdentifier=487843_0_0_



1980 , ZZ430 , 3.92 rear , 700R4 2400 stall NEW EZ EFI 

in Forum: C3 General Discussion


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