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Topic: Ping on acceleration

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Ping on acceleration

Posted: 10/14/07 1:14pm Message 1 of 11
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Gloucester, VA - USA
Joined: 1/29/2005
Posts: 1453
Vette(s): 1979 T-Top, Metallic Green ZZ4 350/355 hp 405 ft/lbs torque Dual Spal Fans 700R4 4 Spd O/D Transmission 2004 Z06 Commemorative Edition

 I'm starting to get a little ping on medium acceleration.  If I remember right the fix is timing. My question is which way?  Hard to check it when it's not loaded right?



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Ping on acceleration

Posted: 10/14/07 1:29pm Message 2 of 11
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retard it a couple of degrees.Smile
turn dizzy clockwise
Joanne2007-10-14 13:30:55


1979 Corvette

Ping on acceleration

Posted: 10/14/07 2:39pm Message 3 of 11
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Frederick, MD - USA
Joined: 9/8/2003
Posts: 3398
Vette(s): 1969 convertible L71 427/435 4-speed black interior
I agree. It's either the timing is a bit too far advanced or too low an octane gasoline.


Ping on acceleration

Posted: 10/14/07 2:50pm Message 4 of 11
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Meredith, NH - USA
Joined: 10/14/2007
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Vette(s): 1977 Coupe,ATM, needs everything
My experience has been from low octane gasoline to timing to a vacumn leak causing a lean ping under acceleration.  The timing usually needs to be advanced if memory serves me correctly. I actually had a car burn a hole in a piston on a lean ping under hard acceleration with the turbo kicked in.  They said it was low fuel pressure that could not keep up with the air being pushed in by the turbo.  Bigger fuel pump and lines cured that after new pistons.


Ping on acceleration

Posted: 10/14/07 6:05pm Message 5 of 11
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
All of the above could do it! Timing too fat for the fuel/compression ratio, too low octane fuel, or vac. leak allowing more air into the cylinders than it needs, which creates a lean burn, and can cause a hole in a slug.
Turn the dist back clockwise just a hair at a time, until the ping goes away. Then get some better fuel!
If there is a problem with the carb not metering enough fuel under part/full throttle conditions, you'll get the same results.
Did you keep an EGR system when you installed th enew engine? An EGR malfunction is the most common cause of pinging these days...


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Ping on acceleration

Posted: 10/15/07 2:19am Message 6 of 11
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Gloucester, VA - USA
Joined: 1/29/2005
Posts: 1453
Vette(s): 1979 T-Top, Metallic Green ZZ4 350/355 hp 405 ft/lbs torque Dual Spal Fans 700R4 4 Spd O/D Transmission 2004 Z06 Commemorative Edition
Nope no EGR ...    Using the best fuel I can get..93 Oct....guess I'll mess with the timing...


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Ping on acceleration

Posted: 10/15/07 2:41am Message 7 of 11
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Victor, NY - USA
Joined: 7/12/2004
Posts: 6841
Vette(s): 2004 Commemorative Edition Coupe, Auto w/HUD. 13K miles in 2015. Sold 1982 Red Coupe
What if it is an '82 with cross-fire injection?
Could it still be timing?
I have noticed that the headlights are coming up and going down slower.
Is that an indication of a vac leak that could be related to pinging?
 



 
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Ping on acceleration

Posted: 10/15/07 5:11am Message 8 of 11
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Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
[QUOTE=dwright] What if it is an '82 with cross-fire injection?
Could it still be timing?

I have noticed that the headlights are coming up and going down slower.

Is that an indication of a vac leak that could be related to pinging?

[/QUOTE]

Yes...


You could also have an injector(or both) stopping up, low fuel pressure due to aged pump, or an issue with an oxygen sensor.
The headlights being slower than normal can be a vac. leak in the system, or just the effects of normal wear & tear on "seasoned" parts. If you have never replaced any of the relays, actuators, or vac. hoses, I'd venture a guess that it is time for a O/H of the headlight system.


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Ping on acceleration

Posted: 10/15/07 9:06am Message 9 of 11
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DUNEDIN, FL - USA
Joined: 10/22/2004
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Vette(s): 1969 COUPE CORTEZ SILVER, BRIGHT BLUE INTERIOR 383 cu. in. 512 HP. Hooker headers w/ side pipes PS PS AC AM FM STEREO. 68,000.MILES C5 5oth Anniversary Coupe , auto.350hp
I had that problem for along time, tried all sort of things, timing wasn`t the issue. I finally decided to play around with fuel additives. the one that works for me is a Lucas oil boast for off road. I use it with a full tank and no more ping. I know this worked for me because i just went through 5 tanks of fuel going to Bowling Green  and ran out of the boast. lo and behind   ping ,ping ping. It cost $9.00  to treat 25 gal, so about $5 a tank.


Ping on acceleration

Posted: 10/15/07 6:27pm Message 10 of 11
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CUYAHOGA FALLS, OH - USA
Joined: 12/2/2003
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Vette(s): 1975 C3 Red, T-Tops, Black Interior. All I need is time and money! Getting there!
In addition, the engine temp could be just a bit higher than before.  That will also make it ping.


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