Author Topic: Help with some fine tuning?  (Read 16416 times)

Offline Got Smoke?

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Help with some fine tuning?
« on: August 01, 2011, 06:45:58 pm »
Ok I've been out of the gasser world for the most part for the last several years. Just recently sold my tow rig Cummins leaving my only truck my 79 Chevy K20, and I want to get it into a more workable status. Let me give you some specs.

350 .030 over, stock style pistons, Edelbrock Performer Intake & 600CFM Carb with one step larger needles & jets, Comp Cams 268 cam, stock HEI distributor, Hedmen Headers, AC delco plugs, & house brand Auto Zone 7mm wires 4spd manual.

The truck runs pretty good when warm, but its a little jerky/sluggish when first starting out on a cold engine. The carb has an electric choke which I do not have hooked up currently, but I am going to look up the directions and set it soon. However its 80 degree's by 7AM here in middle tenn so that's not really an issue this time of year is it?

 I'm more concerned with do I have my timing in the right place? Where should it be set up on a truck like this that see's daily driving and will see towing if the need arise's (NOT my pulling truck in my sig)

Thanks for any help

EDIT I forgot another thing that make me think timing is it does NOT like to start up if the motors hot. I got one of those heat shield blankets this weekend at the local parts store and that still hasn't made any improvement in the problem.
« Last Edit: August 01, 2011, 06:51:43 pm by Got Smoke? »
97 Dodge Cummins modded 12V
02 VW Golf TDI 40+ MPG
79 Chevy K20 350 4spd 5" lift 37 MT OZ's
88 Chevy V3500 / 88 GMC R3500 combo going 3+3 SRW 350/400/205

Offline VileZambonie

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Re: Help with some fine tuning?
« Reply #1 on: August 01, 2011, 07:09:39 pm »
Do you have a standard vacuum advance HEI ignition? Is the vacuum advance hooked up to ported or manifold vacuum?
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74 GMC, 75 K5, 84 GMC, 85 K20, 86 k20, 79 K10

Offline Got Smoke?

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Re: Help with some fine tuning?
« Reply #2 on: August 01, 2011, 07:13:03 pm »
Do you have a standard vacuum advance HEI ignition? Is the vacuum advance hooked up to ported or manifold vacuum?

Yes its a vacuum advance, the hose runs directly from the vacuum advance to a port on the front of the carb. Is this correct?
97 Dodge Cummins modded 12V
02 VW Golf TDI 40+ MPG
79 Chevy K20 350 4spd 5" lift 37 MT OZ's
88 Chevy V3500 / 88 GMC R3500 combo going 3+3 SRW 350/400/205

Offline VileZambonie

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Re: Help with some fine tuning?
« Reply #3 on: August 01, 2011, 07:14:55 pm »
Which port? Is there vacuum there at idle? Pull the hose off and check.
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

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

Offline Got Smoke?

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Re: Help with some fine tuning?
« Reply #4 on: August 01, 2011, 07:30:00 pm »
Which port? Is there vacuum there at idle? Pull the hose off and check.

This one. I started the truck and pulled the hose to make sure and yes there is vacuum at idle. Had a noticeable idle change when unhooked.
97 Dodge Cummins modded 12V
02 VW Golf TDI 40+ MPG
79 Chevy K20 350 4spd 5" lift 37 MT OZ's
88 Chevy V3500 / 88 GMC R3500 combo going 3+3 SRW 350/400/205

Offline VileZambonie

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Re: Help with some fine tuning?
« Reply #5 on: August 01, 2011, 07:45:41 pm »
Hook up the electric choke
,                           ___ 
                         /  _ _ _\_
              ⌠ŻŻŻŻŻ'   [☼===☼]
              `()_);-;()_)--o--)_)

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

Offline Got Smoke?

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Re: Help with some fine tuning?
« Reply #6 on: August 01, 2011, 07:49:36 pm »
Hook up the electric choke

Next on my to-do list. LoL Thankfully not my daily driver. I need to check my timing, suggestions on where to run it at?
97 Dodge Cummins modded 12V
02 VW Golf TDI 40+ MPG
79 Chevy K20 350 4spd 5" lift 37 MT OZ's
88 Chevy V3500 / 88 GMC R3500 combo going 3+3 SRW 350/400/205

Offline 1980c10

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Re: Help with some fine tuning?
« Reply #7 on: August 01, 2011, 09:01:29 pm »
Without a choke even in hot weather expect a 5 min warm up before it runs right. you'll even need to give it a little gas to keep it running if you idle is set low.
You'll need a 12v key on power source to plug into your choke.
Once you have that; to start the engine, turn the key to "on" (warm or cold), press down the gas pedal and let it back up.
this activates the choke and fast idle cam.
the choke is adjusted by loosening the screws around the black disc rotate the disc forward for more choke and backward for less.
 

Offline beastie_3

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Re: Help with some fine tuning?
« Reply #8 on: August 02, 2011, 12:38:18 pm »
I thought distributor should not have vacuum at idle?

Offline topp

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Re: Help with some fine tuning?
« Reply #9 on: August 02, 2011, 12:48:19 pm »
I thought distributor should not have vacuum at idle?

Ditto
'90 Suburban TBI 350

Offline jaredts

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Re: Help with some fine tuning?
« Reply #10 on: August 02, 2011, 02:01:21 pm »
I thought distributor should not have vacuum at idle?
From the factory, no the advance didn't kick in until you open the throttle a little (ported vacuum).  Some like to change it to regular vacuum ports for performance reasons.

Offline GUITAR1989

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Re: Help with some fine tuning?
« Reply #11 on: August 02, 2011, 02:32:48 pm »
Heres the edelbrock carb install videos :) Video IV shows an easy way of grounding the choke to the carb itself. Take a look.

Offline Got Smoke?

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Re: Help with some fine tuning?
« Reply #12 on: August 02, 2011, 04:24:11 pm »
What about the hard starting when hot, even with the protective blanket on the starter?
97 Dodge Cummins modded 12V
02 VW Golf TDI 40+ MPG
79 Chevy K20 350 4spd 5" lift 37 MT OZ's
88 Chevy V3500 / 88 GMC R3500 combo going 3+3 SRW 350/400/205

Offline beastie_3

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Re: Help with some fine tuning?
« Reply #13 on: August 02, 2011, 06:07:36 pm »
describe more about this hard starting. does it crank slowly, or does it crank ok, just takes awhile to actually start?

Offline Got Smoke?

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Re: Help with some fine tuning?
« Reply #14 on: August 02, 2011, 07:05:01 pm »
describe more about this hard starting. does it crank slowly, or does it crank ok, just takes awhile to actually start?

When trying to restart when its in the 190-210 temp range it spins fast like it wants to start but is hesitant to do so.
97 Dodge Cummins modded 12V
02 VW Golf TDI 40+ MPG
79 Chevy K20 350 4spd 5" lift 37 MT OZ's
88 Chevy V3500 / 88 GMC R3500 combo going 3+3 SRW 350/400/205