OK here's an interesting driveability problem

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Jul 30, 2002 | 07:14 PM

73 LS-4

Thread Starter

Melting Slicks

Joined: Jun 2001

Posts: 2,340

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From: Moro IL

OK here's an interesting driveability problem

I think I know what the problem is but I'd like your thoughts on it as well. Anyway at wide open throttle in first gear shifting at 5k rpm or above and then going immediately into 2nd gear and punching the throttle wide open again I get a pretty good bog. Now change the scenario around to 2 to 3rd or 3rd to 4th and this problem doesn't exist or if I short shift into 2nd say shifting out of 1st at about 4000 rpm into 2nd then no bog. Power is great and smooth at all except this point, I can down shift into any gear without this problem either. Fuel system is new from the pump up and Lars just went through the carb, as I said it runs flawless except for that specific situation. Today may have given me a clue as to when I shifted out of 1st at 5500 rpm and went to second and to WOT again it sounded like I got a little bit of a backfire through the intake and then it just layed down real bad, thought I may possibly be running to much total advance, except it's weired that it runs great in all situations except that one. Any ideas

:cheers:
Pat Kunz

Jul 30, 2002 | 07:24 PM

Scott78

Drifting

Joined: Mar 2001

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Re: OK here's an interesting driveability problem (73 LS-4)

See if your mechanical advance is sticky, mine had some grease built up on it and would return slowly. I had similar problems on my WOT 1-2 shift(automatic though) and cleaning it up solved it.

Scott

Jul 30, 2002 | 07:52 PM

Larry B.

Le Mans Master

Joined: Sep 2000

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From: Orlando Floriduh

Re: OK here's an interesting driveability problem (73 LS-4)

I'm not sure how 73's are wired but some 70-75" have TCS (transmission controled spark) which allows vacuum advance in some gears but not others. Maybe someone has a 73 diagram..

[Modified by silvervetteman, 6:53 PM 7/30/2002]

Jul 30, 2002 | 08:57 PM

73 LS-4

Thread Starter

Melting Slicks

Joined: Jun 2001

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From: Moro IL

Re: OK here's an interesting driveability problem (Scott78)

Thanks Scott, I'll check on it

:cheers:
Pat Kunz

Jul 30, 2002 | 08:59 PM

73 LS-4

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Melting Slicks

Joined: Jun 2001

Posts: 2,340

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From: Moro IL

Re: OK here's an interesting driveability problem (silvervetteman)

Thanks for the reply silvervetteman, I think the TCS was the first thing that went into storage off the car though, so that couldn't be it, but 73's did have that.

:cheers:
Pat Kunz

Jul 30, 2002 | 09:07 PM

Matt Gruber

Race Director

Joined: Oct 2000

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From: central FL, near the beach.

Re: OK here's an interesting driveability problem (73 LS-4)

if that happened on my car i would plug in my A/F gauge and see what it did during the problem.
Does it go lean? Rich? Stay the same?
Then i would take it from there.
Not having an A/F gauge reminds me of the pre-internet days; how did i ever get by back then? :lol: