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#1 |
Registered User
Join Date: Jun 2013
Location: nj
Posts: 83
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engine won't start (used to...)
hi.
need help with 'engine not starting' issue. 1979 Chevrolet pickup. project truck (not driven on the road yet). 8 cyl engine 350. 4 barrel carb (I think quad-jet). all looks original. it started and ran fine last autumn, and the year prior to that - it never had any starting issues of any kind. I started it a couple of times over the winter - no issues. this spring I started it up and it ran fine - but after running about 10 minutes it stalled. I have not been able to start the engine since. I tried 'starting fluid'. when I use starting fluid the engine DOES start and runs for a couple of seconds until it uses up the starter fluid. it does this every time, so the engine 'can' start and run. made we wonder if it was getting fuel. a couple of days later (after letting it sit without trying to start it) I disconnected the fuel line from the carb, replaced the fuel filter (since I was in there anyway, and as a test - new fuel filter would be 'dry'). I cranked the engine - without starting fluid - and it still would not start. I then disconnected the fuel line again and found that there was now fuel in there, and the new fuel filter (that I had just put in there 'dry') was saturated and 'wet' with fuel. so, it appears that fuel is getting to the carb. any ideas on what I might check next? thanks |
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#2 |
Registered User
Join Date: Jan 2010
Location: northern arizona
Posts: 259
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Re: engine won't start (used to...)
Sounds to me like gas is getting to the carburetor, but not in it.
The float/needle valve may be stuck shut. Try tapping on the carb body with a screwdriver's plastic handle (so you don't damage anything) a bunch of times, crank it and see if it gets gas in the float bowl and starts. Other than a stuck needle, it could be clogged jets if some crud found its way in. I assume the choke is working properly and closes for a cold start .....
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"Off the grid and on the seven day weekend plan" "One person cannot know everything, but between all of us, there isn't much we don't know." |
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#3 |
Registered User
Join Date: Dec 2011
Location: Regina, SK, Canada
Posts: 622
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Re: engine won't start (used to...)
If it had a filter I would suspect fuel pump. It is working enough to wet the new filter but my guess is it is not pumping enough fuel. Take off the line again and have a buddy turn the truck over and see if fuel is pumping out should be about and ounce and a half per pump. Also since it has not been run much it could be a rusty gas tank instantly plugging the filter. And lastly , it has been known for a person to install another filter in the fuel line somewhere , under truck by tank, along a frame rail etc. Check that too, may be an old inline filter in there somewhere . Are you changing the in carb filter or an inline?
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1979 Chevy Dually Crew 4X4 454, D60 Tru-trac, D70 Detroit Locker, 3.73, 4L80E/NP205 1971 GMC 3/4 Ton 4X4 |
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#4 | |
Registered User
Join Date: Jun 2013
Location: nj
Posts: 83
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Re: engine won't start (used to...)
Quote:
as suggested, I took off the fuel line, cranked the engine, and gas does pump out 'at what appears to be' the rate you mentioned. so, not that. I inspected the filter. it is the one in the carb I replaced (and the only one I can find in the fuel line) and it is clean. so, not that. |
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#5 |
Registered User
Join Date: Jan 2010
Location: northern arizona
Posts: 259
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Re: engine won't start (used to...)
If the problem lies inside the carburetor and tapping on it doesn't un-stuck it, you will need to disassemble the carb.
One thing you need to be aware of when working on Q-jets, when reassembling, extreme care must be taken when reinstalling the top portion as the metering rods hang down and are very easily bent or damaged trying to line them up with the main jets.. In order to line everything up exactly where it needs to be and get a perfect alignment to make for a smooth assembly, you almost need five hands with tiny fingers, all working independently to hold each part in place while setting the top on the main body. Q-jets are tricky, but when done right, they work quite well and dependably. If you decide to rebuild it, you may as well JB weld the well plugs where they are prone to leak in later life. Do a search for the topic, there should be several threads about it here explaining the subject in detail. Keep us posted how you make out with it.
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"Off the grid and on the seven day weekend plan" "One person cannot know everything, but between all of us, there isn't much we don't know." |
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#6 |
Registered User
Join Date: Jun 2013
Location: nj
Posts: 83
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Re: engine won't start (used to...)
still no good...gas not getting 'into' carb
from what I can see, fuel gets right up to the point where it enters the carb, but no further.
Last edited by hplacecf; 04-23-2016 at 06:36 PM. |
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#7 | |
Registered User
Join Date: Jun 2013
Location: nj
Posts: 83
|
Re: engine won't start (used to...)
Quote:
If it IS clogged jets, how does one clean them? forgive my ignorance about quads. I am familiar with old gm singles, so I am aware of the key parts and functions of a carb, but not a quad. thanks |
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