Problem starting truck after sitting overnight.

[bbrriiaann1973]

My truck will not start if it sits over night. The engine just turns over and over acting like it's not getting fuel. If I take off the breather and a pour a little fuel down the carb it fires right up. Once fired up it runs great and has zero problems starting the rest of the day.

The carb is not flooding like it would if I had to hold the throttle down to start it.

I have a 1970 c10 with a 383/700R4, 600 edelbrock carb, mechanical fuel pump.

Any ideas of how to fix it?

[rockyrivermark]

Originally Posted by bbrriiaann1973

My truck will not start if it sits over night. The engine just turns over and over acting like it's not getting fuel. If I take off the breather and a pour a little fuel down the carb it fires right up. Once fired up it runs great and has zero problems starting the rest of the day.

The carb is not flooding like it would if I had to hold the throttle down to start it.

I have a 1970 c10 with a 383/700R4, 600 edelbrock carb, mechanical fuel pump.

Any ideas of how to fix it?

If my truck sits for a long period of time it takes longer to start. Gas bleeds back to the tank, usually a week though.
When it won't start go to carb and manually give it gas at carb.
Gas squirt out down carb? Should be able to see it.
Choke shutting properly at cold start ?
Start with the simple basics first then report back
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[raggedjim]

The fuel pump should prevent the gas from flowing back, if it isn't then it could siphon the fuel bowl. I tested mine by removing it and blowing back through the outlet. Burped gas for 2 days but found out it needed to be replaced.

As long as I start it once a week it is fine now, but longer than that and I have to crank the bowl full.

Good luck, Rg

[bbrriiaann1973]

It acts like it's not pumping enough fuel at low engine speed, it's a hi performance fuel pump designed to pump max pressure at high rpms. Would going to a normal stock fuel pump fix the problem?

I have installed a helper fuel pump in line of the mechanical fuel pump and it seems to help a little.

Cranking engine 30 times vs say 20 times with the helper fuel pump.

[Hubscrub]

Originally Posted by bbrriiaann1973

It acts like it's not pumping enough fuel at low engine speed, it's a hi performance fuel pump designed to pump max pressure at high rpms. Would going to a normal stock fuel pump fix the problem?

I have installed a helper fuel pump in line of the mechanical fuel pump and it seems to help a little.

Cranking engine 30 times vs say 20 times with the helper fuel pump.

You do not need a helper fuel pump, or a high performance one for that matter. Carbs don't need much fuel pressure to run correctly. Edelbrocks are pressure sensitive more so that other carbs. A stock style mechanical fuel pump is ALL you need.

[geezer#99]

Do you have a heat plate between the carb and the intake?

Do you have a working choke?

[bbrriiaann1973]

No heat plate. Electric choke is not hooked up

[Rufas]

Originally Posted by bbrriiaann1973

No heat plate. Electric choke is not hooked up

There's your problem. With power off, hook up the electric to a switch source and then adjust the choke. The choke is there for a reason, especially during winter months.

[HO455]

Are you running a Quadrajet? If so the problem is likely one of the well plugs below the float bowl is leaking and draining the float bowl overnight. You can pull the carb when it is warm and check for drips. (Sometimes they won't leak cold) If it takes a lot of cranking of the starter before it starts in the morning I would suspect the fuel pump being weak as an additional issue.
Good luck.

[bbrriiaann1973]

No I have a edelbrock carb

[HO455]

OK. Have you pulled the air cleaner and looked down the carb and watched the fuel spray when you wing the throttle? Doing this first thing when cold and later when warm so you can compare is valuable info. You should see two good strong streams of fuel spraying from the primary side.

[rockyrivermark]

Electric choke is not hooked up.
Hard to cold start
Hmmm? What could it be?

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[Rufas]

Originally Posted by rockyrivermark

Electric choke is not hooked up.
Hard to cold start
Hmmm? What could it be?

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[WorkinLonghorn]

Well, in BBrriiaann1973's defense, he lives in Phoenix. 40's and 50's and a few 30's maybe, same as here in L.A. I disconnected my choke over 20 years ago and have never had one problem with it starting right up after a few pumps of the peddle.
He just needs to take the advice here and check to see if the accelerator pump is spraying fuel into the venturi when the throttle is manually operated and if not then he needs to figure out why the bowl is dry (leak or draining back?) and fix it. -BA

[Blakeman350]

Originally Posted by rockyrivermark

Electric choke is not hooked up.
Hard to cold start
Hmmm? What could it be?

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If sarcasm if the best solution you can contribute maybe you shouldn’t contribute at all. Just my opinion.

I had a similar problem on my 67 and I figured out it was a loose hose clamp on the rubber line between the pump and the line filter before the carb. Turns out it was just enough of a leak to drain the line and the float without leaving much indication.

[Rufas]

Originally Posted by Blakeman350

If sarcasm if the best solution you can contribute maybe you shouldn’t contribute at all. Just my opinion.

I had a similar problem on my 67 and I figured out it was a loose hose clamp on the rubber line between the pump and the line filter before the carb. Turns out it was just enough of a leak to drain the line and the float without leaving much indication.

OK not trying to be a smart a$$, but how would that drain the float bowl? Fuel enters from the top of the carb not from the bottom.

[Blakeman350]

Originally Posted by Rufas

OK not trying to be a smart a$$, but how would that drain the float bowl? Fuel enters from the top of the carb not from the bottom.

When the fuel drains out of the rail, line and filter and refills enough times eventually dirt and debris worked in the system ( if fluid can leak out dirt can get in) and got in the needle and seat and drained the primary bowl. I was in the middle of an appointment when I posted earlier and left that part out.

[rockyrivermark]

Most times things like this are a process of elimination
So start with the easiest first.
Next time it won't start manually close the choke at the carb while I buddy tries starting it. Like several of us suggested also see if gas is squirting down carb. Two of the simplest things to do that tell you a lot.
If that doesn't help then move on to fuel line, fuel pump or carb components.
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[bbrriiaann1973]

Had problem before and after I had carb rebuilt

[RichardJ]

For an overnight problem, you need to check the fuel lines between the tank and the fuel pump. A small leak there will allow the pump to pull fuel from the tank and air through the leak. It will run fine with no indication of a leak. With the engine off, fuel seeping through a small leak can evaporate fast enough, it will never drip on the ground.

Wrap a rag around an air nozzle and with the air pressure set really low, blow air into the fuel tank and hold. Have someone visually inspect the fuel lines for a leak.
If no leaks are found, I'd suspect the fuel pump.

[OBS454]

The choke needs to be functional. Worked as a mechanic in south Texas for many years ... rebuilt a lot of carbs and set a lot of chokes for people having this same problem. Didn't take much of a drop in temperature for this problem to arise. The choke is part of the fast idle system also. Too low of an idle setting will cause problems also. Cold start choke butterfly should shut all the way when pedal is depressed (if vacuum choke pull off is in place to open the blade immediately - if not don't adjust it to where the blade closes completely) all the way on cold engine (not too strong on the spring - just enough to close). If you manually open the throttle while holding the choke closed you should notice the throttle resting position to now be slightly higher than before (fast idle cam adjusting screw holding it open) Depending on how good the accelerator pump is, a couple of pedal pushes all the way should throw enough fuel into the engine. Upon engine start the vacuum choke pull off should be adjusted to where the closed blade pulls open to the approximate width of a #2 pencil at the rear of the choke butterfly AND the fast idle cam is set to increase engine speed to approximately 1500 RPM. Tapping the pedal will often kick the idle down to the next step on the cam once the engine begins to run. During this time the choke should be receiving whatever voltage it is rated for and begin to move the metal coil. So, the engine is beginning to warm and the choke cap is beginning to warm. As the warming progresses you can tap the pedal again and the choke linkage should move down to the next step on the fast idle cam or completely off of it as the choke butterfly continues to open to it's final vertical position. You may have to bend linkage here or adjust the fast idle there and change the position of the choke cap. Don't just look at one piece of the system. All work together and you probably won't get it perfect the first time - let it get cold and fine tune it till it's right. When set correctly it's really nice.

[B. W.]

Agree with what others have said. IMO, you do not have a fuel supply problem, you need a choke.

To confirm you have fuel in the carburetor:

Let the truck sit overnite.
Remove the air filter lid & look down the carb
Work the throttle with your hand going to wide open throttle
You should see fuel squirting out of the pump squirters (located between the front two holes, at the front of the carb)

If fuel is coming out of the squirters you have fuel in the carb. You do not have fuel issues.

Wire up your choke to key on power & check your adjustments. Instructions are on the Edelbrock website.

[Aberdare]

Originally Posted by B. W.

fuel squirting out of the pump squirters (located between the front two holes, at the front of the carb)

The "Squirters" you are referring to is the Accelerator Pump. Every Carburetor has Five (5) Fuel Circuits and each has their own specific job to perform to deliver fuel... These fuel circuits are; (1) Idle, (2) Low Speed, (3) High Speed, (4) Accelerator, and (5) Choke.

In regards to being hard to start after sitting overnight, if the Fuel Bowl is Vented (which alot of the older carburetors are)... a simple fix which is often overlooked, is the Bowl Vent being stuck open or in some cases, the vent components are missing altogether... allowing fuel to simply evaporate, thus emptying the Fuel Bowl or not having enough fuel in the bowl to allow for a proper cold start.

A properly set-up, adjusted and tuned carburetor will have all five (5) circuits functioning properly, thus to allow for proper cold starts, as well as warm starts & HOT restarts of the engine under all environmental conditions.

Consult the manufacturer specifications for your model, to properly "Bench-Set" your carburetor, prior to any final adjustments with the engine running.

Just my $0.02 worth.

[B. W.]

To be specific, the "squirters" are called "accelerator pump nozzles". They are part of the accelerator pump circuit. It's just easier to say (type) squirters. The accelerator pump itself is located on the left front corner of the carb. the attached picture shows one that someone "re-built" & installed the pump diaphragm upside down. If you look closely you can see the rebuilder (I use that term loosely) also bent the tip of the metering rod. Believe it or not, this engine ran pretty good, just a little rich due to the needle.

As far as the gasoline in the fuel bowls evaporating overnite - not gonna happen. All carburetors are vented, the vent system is controlled on newer carbs to reduce evaporative emissions. (Edelbrock Performer series carbs are open vent) But, regardless of the type of venting, you will not lose enough fuel overnite to make a difference. If you see fuel coming out of the accelertor pump nozzles you have fuel in the bowls.

[bbrriiaann1973]

Thanks for the info, so not having the choke hooked up will not put enough fuel at start up?

Because once it starts up it runs great for the rest of the day. Starting and stopping