Won't start after sitting for a few days.

[TjBlueRusty]

I have a 75 Chev C-10 pickup with a 350 and orginal carb that will not start after sitting for a few days. I can pour a little gas in the carb bowl and it fires right up. It will start and run fine up until it sits again. The fuel hoses are new and I can find no gas leaks. Is the fuel pump the issue?
Thanks.

[Eyegore]

More than likely the pump if eveything has been replaced, check on the manifold to see if anything is leaking out of the bowls though also check all the hose fittings.

[cableguy0]

IS your accelerator pump squirting fuel when you open the throttle? After the choke is open Look down into the carb and open the throttle you should see gas squirt out. If you have a bad fuel pump the truck wouldnt run. If the accelerator pump isnt squirting fuel pumping the gas will do nothing. Is there a hesitation when you hit the throttle hard from a stop?

[motornut]

I read "hoses",does that cover the sending unit?seen them crack and let air in at the bend coming out of the tank
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[TheWhiteElephant]

Originally Posted by TjBlueRusty

I have a 75 Chev C-10 pickup with a 350 and orginal carb that will not start after sitting for a few days. I can pour a little gas in the carb bowl and it fires right up. It will start and run fine up until it sits again. The fuel hoses are new and I can find no gas leaks. Is the fuel pump the issue?
Thanks.

I'm assuming you are running a QJet, correct? That problem sounds like the typical QJet leaky bottom plugs. These are on the main body of the carb and are plugged with either brass or aluminum plugs. The "reserve" fuel supply in the carb leaks out after the vehicle is off for a while. Therefore, when you go back to start it, there is no fuel in the carb. That is why it will start right up when you pour fuel in there.

The earlier QJets ('74 and earlier) were notorious for this, but apparently there are many '75 and up carbs that suffer the same issues. That is why many plug up the plugs, sometimes with epoxy, screws, etc. when they are rebuilt.

[TheWhiteElephant]

Look at the last photo on post #53 to see what I'm talking about. By the way, some experts say the epoxy/JB Weld won't work, but others say it does...

http://67-72chevytrucks.com/vboard/s...=430367&page=3

[Hoods69BadBowTie]

Originally Posted by TheWhiteElephant

I'm assuming you are running a QJet, correct? That problem sounds like the typical QJet leaky bottom plugs. These are on the main body of the carb and are plugged with either brass or aluminum plugs. The "reserve" fuel supply in the carb leaks out after the vehicle is off for a while. Therefore, when you go back to start it, there is no fuel in the carb. That is why it will start right up when you pour fuel in there.

The earlier QJets ('74 and earlier) were notorious for this, but apparently there are many '75 and up carbs that suffer the same issues. That is why many plug up the plugs, sometimes with epoxy, screws, etc. when they are rebuilt.

That's exactly what I was wandering and going to suggest the same thing. A bad fuel pump would work or not work at all. Have you checked the fuel filter lately?
Posted via Mobile Device

[TjBlueRusty]

Thanks everyone for your posts.

I'll first try some JB Weld on the bottom plugs.

This old truck sat for 10 yrs without being started. After removing the pack rats nest off the engine and replaced several chewed off plug wires it fired right up. I never thought it would run again. 120k on the engine but uses very little oil...mostly from the value covers (next on the fix list). I've redone the brakes, repacked the front wheel bearings, welded & redrilled the top shock mount that pulled through, put on new front shocks, and had to splice in wires that were missing for the lights, fuel gauge etc. But for me the real enjoyment was doing it with my 10 yr old son who likes ridding in it and thinks grandpa's old truck is pretty neat even if it's badly rusted out. Thanks again, I appreciate the help.

[78 Chevyrado]

Every time this happened to me, It was a bad fuel pump... And it only happened after the truck sat for 3 days or more.

The pump worked fine once you got it started, but it would allow the gas to drain back to the tank, which sucked the fuel bowl in the carb dry, which was why it would only start with some gas poured in the carb. I took the top of the carb off one day and the bowls were dry, I think something inside just dry rotted and let the fuel reverse flow. got a new pump and never had a problem again (Once I started driving it Regularly) When grandad had the truck and cranked it up every few months, he had to put a new pump on it every year. They don't do well sitting.

[VegasBruce]

I would look at the accelerator pump also. If it cranks good but won't start till you pour gas down it, but stays running the fuel pump should be good. Its just not getting enough gas for the initial fire.

[TheWhiteElephant]

I would strongly recommend a carb rebuild. If you've never done a QJet rebuild before, there are some great videos on Youtube that show you how. It is really a lot easier than it seems.

[PRattenbury]

The engine will run with a bad fuel pump. Assuming the hoses are all okay and the filter is okay, the fuel pump would be the next cheapest and most logical place to look next. Always start with the cheap stuff first, if the answer isn't glaringly obvious.

[TheWhiteElephant]

You could certainly try the fuel pump first, but if the car sat for over 10 years, you can bet that the carb definitely needs a rebuild. The kit will cost you about $16.99.

[VegasBruce]

Originally Posted by TheWhiteElephant

You could certainly try the fuel pump first, but if the car sat for over 10 years, you can bet that the carb definitely needs a rebuild. The kit will cost you about $16.99.

That is my thought also.