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 Post subject: Tuning Problem
PostPosted: Tue Mar 01, 2005 6:56 pm 
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EFI Slant 6
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Joined: Thu Jul 15, 2004 12:56 am
Posts: 496
Location: Los Angeles
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okay, i've been trying to figure this out on my own to no avail.. so help please..

225
holley 2300 carb
super six setup

heres the thing, the car runs like crap, i've been messing with timing and the carb, but i'm not really following any guidelines, just winging it..

so what should i set my initial timing to, and how do i go about doing that...???

and where should i start with the carb.. i've been trying to tune this thing for so long now, i'm actually just frustrated...

any input would help...

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 Post subject:
PostPosted: Tue Mar 01, 2005 7:02 pm 
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Joined: Tue Jul 08, 2003 11:33 am
Posts: 2378
Location: Central GA
Car Model: Many & varied, including stock & hopped up /6's
Suggestion: Trash the Holley 2300 and place a Carter BBD on it. :idea:

D/W

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 Post subject:
PostPosted: Tue Mar 01, 2005 7:37 pm 
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Joined: Fri Feb 18, 2005 5:24 pm
Posts: 9
Location: New Jersey, Bergen County
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Turn the mixture screws in all the way , then out 2 1/2 turns. Start the car and let it warm up, then set the idle at 700RPm. Now turn the idle mixture screws inward (clockwise) 1/4 turn at a time, adjusting both screws the same amount. Do this until the engine starts to run rough, then back the screws out 1/2 a turn. Reset the idle speed to 700RPM, and adjust the mixture again. When that's set hook up a vacuum guage and adjust the timing to achieve maximum vacuum at idle. It should be around 10* BTDC, and your vacuum gauge should read around 20 with a steady hand. That shoud give you a pretty good place to start, then you can fine tune the idle mixture screws and timing after you have driven the car. Also, check for vacuum leaks.


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 Post subject: Timing.
PostPosted: Wed Mar 02, 2005 5:35 am 
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Joined: Tue Jul 27, 2004 9:27 am
Posts: 824
Location: Pittsburgh, PA
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Quote:
It should be around 10* BTDC
Depending on the year and model. Get the timing spec for your car, and then set it to that before tuning your carb.

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 Post subject:
PostPosted: Wed Mar 02, 2005 12:13 pm 
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Joined: Mon Jan 12, 2004 4:20 am
Posts: 2011
Location: Argentina
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I'd set the timing first then adjust carburetion to match your timing. I alwasy do this: set timing (knowing beforehand how much total I have, that involves getting out reluctor and pickup plate and schecking out on your govnor, one you're there you may wanna recurve the thing to get more power off the line, huh?)

then I start by turning 1 1/2 turn each idle screw, I fire her up and let her warm up choke connected, then hook up a vac gauge on the brake booster hose and remove choke. I gradually and evenly go under 1 1/2 turn on each idle srew (1/4 turn on each at a time) til she starts to stumble, then go out again till max vac reading is obtained. (Before you go for a drive, remember to hook up the brake booster again :wink: )

If you recurved, and you have above 10º BTDC initial, I'd sugegst #53 jets... but in some post MitchB gave the most usefull advice I ever heard about rejetting: hook up a permanent vac gauge and mount it up inside the car, then cruisin at the same speed, if your larger jets produce higer vac reading, you're there, you're making more power at less throttle opening.

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 Post subject:
PostPosted: Mon Jun 13, 2005 9:12 am 
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Turbo EFI
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Joined: Tue Mar 11, 2003 5:09 am
Posts: 1167
Location: Troy, Texas
Car Model:
Quote:
Turn the mixture screws in all the way , then out 2 1/2 turns. Start the car and let it warm up, then set the idle at 700RPm. Now turn the idle mixture screws inward (clockwise) 1/4 turn at a time, adjusting both screws the same amount. Do this until the engine starts to run rough, then back the screws out 1/2 a turn. Reset the idle speed to 700RPM, and adjust the mixture again. When that's set hook up a vacuum guage and adjust the timing to achieve maximum vacuum at idle. It should be around 10* BTDC, and your vacuum gauge should read around 20 with a steady hand. That shoud give you a pretty good place to start, then you can fine tune the idle mixture screws and timing after you have driven the car. Also, check for vacuum leaks.
I guess I must have missed this when it was first posted back in March. Unless my father-in-law has a vacuum gauge stuffed away somewhere in his shop we are using, I'll have to get one for this procedure. So far, we have the engine running fairly good, without benefit of a tach or vacuum gauge. Last week, I picked up a tach/dwell meter. Now, we will know what rpm it is running. I can't wait to see how it runs after this.

Anyone care to list the steps to tuning a completely rebuilt slant with electronic ignition, in order of priority? I suspect initial valve lash is at the top of the list, and basic carb settings for idle and fuel/air, oh, and timing. I ocassionally see discussions about things you have to go back and readjust, because something else affects it, like fuel/air mix and idle. Are there any settings you can adjust and then leave alone (like lash)?

This would be a great topic for an article by some of you.
Jerry

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