Author Topic: 86 Chevy K5 with carbed 305 not getting gas into carb  (Read 3669 times)

Offline VTK5Mudder

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86 Chevy K5 with carbed 305 not getting gas into carb
« on: September 15, 2018, 03:02:50 AM »
Hello , I got a 86 Chevy K5 with a 305 and 4bl carb [ not original motor ] ive had the blazer for around 5 or 6 yrs now and its just been used to play in the mud with . 2 yrs ago I had to replace the fuel pump and all was good the last 2 yrs now I haven't used it for anything but always moved it around yard to keep it going and its been fine last fall I parked it for the winter I keep it cleaned during the winter and try and start when I can last winter I couldent get it to start but it would turn over . I thought maybe the in carb gas filter was just plugged as I pulled line off pump and gas was flowing good so I got the filter and still no gas going into carb . after I put it in I pulled it back out and filter was dry and pulled the 5/8 line off the 1" line and gas was going up to and sprayed to the other side of motor hooked back up and nothing going in carb . today I was tinkering on it and first I pulled filter out after trying it a couple times and filter felt damp and smelled like gas put it back together and again nothing going into carb . it will fire up if I put a little gas in the carb but wont keep running of course , was hoping it would help gas into carb or ?? I tried wrapping on carb a little just to see if it was the float but to no good . I'm not a carb guy at all but pump seems good and gas is all the way up to carb so what is wrong ? I need to get this going as I need it out of the yard and running will sell better then not running , thanks for any help !

Offline VileZambonie

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Re: 86 Chevy K5 with carbed 305 not getting gas into carb
« Reply #1 on: September 15, 2018, 08:48:34 PM »
You lost me at 5/8 line and 1" line. Are you referring to the fitting size? Is fuel pumping out of the pump? If it is and if you spray fuel into the carburetor resulting in it starting, then the problem is within the carburetor.
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              ⌠ŻŻŻŻŻ'   [☼===☼]
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline VTK5Mudder

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Re: 86 Chevy K5 with carbed 305 not getting gas into carb
« Reply #2 on: September 16, 2018, 01:43:05 AM »
yes sorry I mint to say that , and yes fuel pumping out the pump and all the way to the carb so pump is still good just cant fig. out why its not going in carb .

Offline JohnnyPopper

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Re: 86 Chevy K5 with carbed 305 not getting gas into carb
« Reply #3 on: September 16, 2018, 01:55:23 PM »
is is a Rochester? float valve stuck? try filling the float bowl through the vent hole at the front of the carb, look for a 3/8" tube, 4 oz of gas, it will run till dry again, but maybe the vibration will free the valve.
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction

Offline VileZambonie

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Re: 86 Chevy K5 with carbed 305 not getting gas into carb
« Reply #4 on: September 16, 2018, 06:32:40 PM »
Rebuild or replace the carburetor.
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline VTK5Mudder

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Re: 86 Chevy K5 with carbed 305 not getting gas into carb
« Reply #5 on: September 18, 2018, 02:33:22 AM »
is is a Rochester? float valve stuck? try filling the float bowl through the vent hole at the front of the carb, look for a 3/8" tube, 4 oz of gas, it will run till dry again, but maybe the vibration will free the valve.
Its a Rochester . I wondered if the float was stuck I know years ago we used to just give them a few taps and sometimes that would work I tried that and it didn't of course lol ill try the gas down the vent tube anything is worth a try . I just don't have the time and never have done a rebuilt on a carb before . I was hoping a little gas down the carb would get it going but that didn't work either .

Offline JohnnyPopper

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Re: 86 Chevy K5 with carbed 305 not getting gas into carb
« Reply #6 on: September 18, 2018, 05:54:19 AM »
I know Rochester's can be intimidating, but they're more simple than they look.

If I can offer anything it's this:

Get the number off your carb to match with a rebuild kit. Even if you don't go deep into a rebuild, you will probably tear the top gasket.

Working a rebuild on the bench is much easier than being hunched over the engine, you want to change out the base gasket anyway.

The choke linkage needs to be undone before the top can come loose.

The main valve replacement is easier than it looks, setting the float level is too. Take your time, and take Pictures...

When you're dropping the top assembly back on, the metering rods (big ones) tend to hang up. Open the throttle valve slightly and she will drop in like a cat into your lap.

Finally, a thin coat of grease on the base gasket will help seal against vacuum leaks, don't over tighten the four main bolts.

Hope that helps and you are back to rocking your Chevy!
1957 Apache 3100 235 Inline 6, 3 on the tree
1973 C-20, 3+3 454 4BBL TH400  Water Injection
1978 K-10, 350 4BBL TH350 NP203 M.M. Part time Kit/Hubs
1980 C-10 under construction