Hard Start and Will Not Idle? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

YourBuddy'sTruck · 08-12-2014, 09:08 AM

So, I am passed all my ignition trouble, I think.

Now it will not start unless I pump the heck out of the pedal and then hold it to the floor.
Then, it only runs rough with the pedal half down...and still like it's laboring to do that?
No way it'll idle.
I see a lot of smoke too.
I'm thinking my carb is the issue. And all I know about it is that it's a Q-jet.
It's acting like the engine is either getting no gas or flooded.

I verified timing at 10-12* on #1
How do I tell if my float is stuck? Or the needles?
Any advice, help, nudge is greatly appreciated.

'70 C20 350 with HEI
Was running great until my module went out. Then a comedy of errors, including running without a fuel filter, to get home.

Longhorn 70 · 08-12-2014, 10:10 AM

If the float is stuck gas will bubble out of the carb vents

YourBuddy'sTruck · 08-12-2014, 07:53 PM

Yep. Blowing fuel everywhere.
I know what I starting tonight....

Thanks for the nudge of knowledge.
Cheers!

davepl · 08-12-2014, 07:57 PM

Float level is really sensitive in Q-Jets. It varies by application, so you'll need to look in the shop manual to find out what it should be.

I can't see from this angle, but at the front of where your carb sits you don't have a long slot with two holes (not bolt holes) going down into the intake, do you?

YourBuddy'sTruck · 08-12-2014, 09:18 PM

Quote:

Originally Posted by davepl

I can't see from this angle, but at the front of where your carb sits you don't have a long slot with two holes (not bolt holes) going down into the intake, do you?

No. There's nothing like that. Why? What is the slot and holes all about?

There will be a HUGE lerning curve on this one! I've never been inside any carb more complicated than my Dellorto UB 24 BS. (simplest carb out there!)
I'll be reading here a LOT!

I know you guys will all help me out in archive or live form.
We all dragged this truck out of a feild and got'er running together!

SCHRUMGMC · 08-12-2014, 10:51 PM

Vacuum leak...its what I am dealing with

YourBuddy'sTruck · 08-12-2014, 10:59 PM

My Float is metal and empty of fuel. (That makes me happy!)
Also, it was bent down a bit.
I "leveled" it and, I guess, need to adjust it to the level for my use on a 350?
I'll find that info in my Haynes manual or somewhere here.
Regardless...parts bathed and soaking.
Hope to have good run in the AM as I need this truck rolling Thursday Morn!
= [\

YourBuddy'sTruck · 08-13-2014, 06:26 PM

Up till Midnight reading and researching after cleaning carb parts.
8 AM...Rebuild Kit in hand!
12:30 the carb was back on.
I went to bump it over just to fill the bowl and check my lines for leaks...
And it fired right up!
Used to have to pump the heck out of it, not anymore!
And the quick power response, wow!
Set the timing with the light and it's like a different truck.
I've only driven it a bit, but will more tomorrow.

One thing is that the throttle is REALLY quick now.
My kit came with some different part for the Jet under the float tab.
This one is slotted and mine was solid?
Also, my old setup had no clip from that jet to the float tab?
And I know now why my choke doesn't work...it's missing a few parts?
I'll be getting another carb, rebuild that, and replace this one for sure.
Cheers! You all helped me a great deal with all the older posts..

08-12-2014, 10:10 AM	#2
Longhorn 70 Registered User Join Date: Dec 2012 Location: Chandler AZ Posts: 1,149	Re: Hard Start and Will Not Idle? If the float is stuck gas will bubble out of the carb vents __________________ 1970 Longhorn, Front Disc, 350/4 bolt, 882 heads, HEI, Edelbrock, 700R4, HO-52/4.11. 1996 Corvette, Collector Roadster, LT4, 396, 450RWHP, 6sp, 4.11/Dana44/posi 5 point roll bar And let us not grow weary of doing good, for in due season we will reap, if we do not give up. Gal 6:9

08-12-2014, 07:53 PM	#3
YourBuddy'sTruck Registered User Join Date: May 2013 Location: Catawba Island, OH Posts: 203	Re: Hard Start and Will Not Idle? Yep. Blowing fuel everywhere. I know what I starting tonight.... Thanks for the nudge of knowledge. Cheers! Attached Images

08-12-2014, 07:57 PM	#4
davepl Registered User Join Date: Aug 2006 Location: Redmond, WA Posts: 6,332	Re: Hard Start and Will Not Idle? Float level is really sensitive in Q-Jets. It varies by application, so you'll need to look in the shop manual to find out what it should be. I can't see from this angle, but at the front of where your carb sits you don't have a long slot with two holes (not bolt holes) going down into the intake, do you? __________________ 1970 GMC Sierra Grande Custom Camper - Built, not Bought 1969 Pontiac 2+2 427/390 4-speed Coupe 1969 Pontiac 2+2 427/390 4-speed Convertible

08-12-2014, 10:51 PM	#6
SCHRUMGMC Registered User Join Date: Dec 2012 Location: North Carolina Posts: 4,989	Re: Hard Start and Will Not Idle? Vacuum leak...its what I am dealing with __________________ 1971 GMC Sierra 1959 GMC 100

08-12-2014, 10:59 PM	#7
YourBuddy'sTruck Registered User Join Date: May 2013 Location: Catawba Island, OH Posts: 203	Re: Hard Start and Will Not Idle? My Float is metal and empty of fuel. (That makes me happy!) Also, it was bent down a bit. I "leveled" it and, I guess, need to adjust it to the level for my use on a 350? I'll find that info in my Haynes manual or somewhere here. Regardless...parts bathed and soaking. Hope to have good run in the AM as I need this truck rolling Thursday Morn! = [\ Attached Images

08-12-2014, 09:08 AM	#1
YourBuddy'sTruck Registered User Join Date: May 2013 Location: Catawba Island, OH Posts: 203	Hard Start and Will Not Idle? So, I am passed all my ignition trouble, I think. Now it will not start unless I pump the heck out of the pedal and then hold it to the floor. Then, it only runs rough with the pedal half down...and still like it's laboring to do that? No way it'll idle. I see a lot of smoke too. I'm thinking my carb is the issue. And all I know about it is that it's a Q-jet. It's acting like the engine is either getting no gas or flooded. I verified timing at 10-12* on #1 How do I tell if my float is stuck? Or the needles? Any advice, help, nudge is greatly appreciated. '70 C20 350 with HEI Was running great until my module went out. Then a comedy of errors, including running without a fuel filter, to get home.

08-13-2014, 06:26 PM	#8
YourBuddy'sTruck Registered User Join Date: May 2013 Location: Catawba Island, OH Posts: 203	Re: Hard Start and Will Not Idle? Up till Midnight reading and researching after cleaning carb parts. 8 AM...Rebuild Kit in hand! 12:30 the carb was back on. I went to bump it over just to fill the bowl and check my lines for leaks... And it fired right up! Used to have to pump the heck out of it, not anymore! And the quick power response, wow! Set the timing with the light and it's like a different truck. I've only driven it a bit, but will more tomorrow. One thing is that the throttle is REALLY quick now. My kit came with some different part for the Jet under the float tab. This one is slotted and mine was solid? Also, my old setup had no clip from that jet to the float tab? And I know now why my choke doesn't work...it's missing a few parts? I'll be getting another carb, rebuild that, and replace this one for sure. Cheers! You all helped me a great deal with all the older posts..



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