Thread: Timing Issue? I wish I could get this thing to stop pinging!

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OK, fixed several problems only to uncover more, now after new plugs and an adjustable vac can my truck PINGS under various conditions.

I have my initial timing down to 10 degrees and have eliminated all but a few situations, namely hard accelerating out of a turn. Partial and WOT throttle under load (going up hill) no longer ping but if you goose hard it coming out of a turn it will ping, but if you accelerate moderately and build to full throttle it is OK...

I really wish I could get it back to how it behaved with the *wrong* plugs in regards to not pinging...

I was thinking about lighter mech adv weights in my dizzy and playing with spring combos and adding vac adv to tune my curve, as it is I am all in around 2000 RPM - and right now my total mechanical advance is 15 degrees

Any thoughts gentlemen?

hard for me to think your all in at 2000 with stock springs .if so thats a first for me ? stock springs will not come all in at 2000 no way

Originally Posted by pat mccarthy

hard for me to think your all in at 2000 with stock springs .if so thats a first for me ? stock springs will not come all in at 2000 no way

Hard for me to believe too but I have the results documented over several tests I've run

Keep in mind, this is with the vac adv disconnected...

If your wanting to run 87 octane try restting the fan so you are at 160 deg. again. Also try a cooler plug. Here in the Midwest 91 octane is available most places. 93 octane and you have to know where to get it. So in my opinion 91 octane is pump gas. Also how much vac. advance do you have?

What happens when you spend the extra 10 cents a gallon and buy 89 octane? Does it still ping? Gas is lousy these days and ethanol is even worse. I even run mid grade in my Honda daily because that puts it where it likes to run best.

What happens when you spring for high test?


Don

Originally Posted by Itoldyouso

What happens when you spend the extra 10 cents a gallon and buy 89 octane? Does it still ping? Gas is lousy these days and ethanol is even worse. I even run mid grade in my Honda daily because that puts it where it likes to run best.

What happens when you spring for high test?
Don

Itoldyouso: 369568

Hi People,
May I suggest that you set everything back to regulation timing etc
and use a different fuel depot for a few weeks...All the best..Skyeking

Check your float level

This will sound elementary and I sure don't want to insult you, but have you checked your vacuum hoses?

I has a sort of similar problem and tracking it down gave me fits.

Jim

Check out this guy call Lars Grimsrud. I have used his articles to tune my 327 with vortec heads and Proform HEI. I replaced the adjustable vac can with a stock vac can he listed (AR31 $9 Auto Zone) and it has tuned my motor very well.
http://www.corvetteclub.org.uk/files...and_timing.pdf
http://www.nastyz28.com/~ericf/tech/vacadvance.pdf

Originally Posted by 18436572

Check out this guy call Lars Grimsrud. I have used his articles to tune my 327 with vortec heads and Proform HEI

Cool, thanks!

A colder plug has the proclean cone that is shorter ( pulled more into the threaded part), bad explaination.

Originally Posted by Mikej

A colder plug has the proclean cone that is shorter ( pulled more into the threaded part), bad explaination.

I was looking for a specific, colder plug for my application but thanks for the explanation!

In the mean time I found a few Champion and Autolite plugs I could try

Dont know if this might possibly help but here it is anyways.
http://www.acdelco.com/parts/sparkpl...tification.jsp

how much are you pulling for adv with vac hook up? have you added a race fule to see if it go s away ? for plugs just a AC 44 or cross it over to auto lites .you want to pull as much adv as you can off idle. use a justable vac adv to pull some out if needed and it needs to drop out under load .or go full mechanical adv .i start at getting it all in at 2800 and 32 to 36 total to start.did you try ligter set up springs in the carb ? how much vac is it pulling when its pinging ?

Real good questions Pat, I'll do my best to answer

Originally Posted by pat mccarthy

how much are you pulling for adv with vac hook up?

Current timing looks like this: 34* total advance, 10* initial, 14* mechanical, 10* vacuum adv w adj can
RPM - Advance
1000 - 12*
1250 - 16*
1500 - 23* - HUGE jump in curve, must be where the vac kicks in...
1750 - 29*
2000 - 32*+
2250 - 34* - All In

It still pinged a wee bit with light throttle from cruise and if I hammer it out of the hole - I did note that if I ramp up the throttle evenly it will not ping under either of these circumstances. FWIW I drove the piss out of it late last night but the air is much cooler at night, no wonder it behaved!

have you added a race fule to see if it go s away ?

Not yet, still working with 87 octane, not sure if the next step will be 89 or 91, trying to keep it cheap-pump gas friendly if possible. 95-97 octane race juice is available here but I think it is still over $5 a gallon

for plugs just a AC 44 or cross it over to auto lites

I am not sure if AC44 is correct for my application, it is a 14mm thread but only 7/16 reach and 13/16 wrench - I cannot fit a 13/16 socket on #1, #2, #7 and #8 cyls due to head bolts, the vortec heads need a 5/8 spark plug and the reach needs to be over .7" to get into the chamber from what i have found... but what the heck do I know?

The Autolite plug I found was a 605, the next colder is a 104 (5144) and the second colder is a 103 (5143) all three are resistor plugs

.you want to pull as much adv as you can off idle. use a justable vac adv to pull some out if needed and it needs to drop out under load .or go full mechanical adv .i start at getting it all in at 2800 and 32 to 36 total to start.

I am down around 8 to 10 degrees at idle to avoid pinging while under load. The adj vac can i have ADDS advance, so I have been retarding the initial timing and adding it back with the can. I was running with full mechanical advance but did not get more than 22* total and was all in below 2000 RPM. I will go to lighter springs in my dist to see if I can milk out more mechanical advance than 15 to 18 degrees

did you try ligter set up springs in the carb ?

I did put stiffer step up springs in to keep it a bit richer with good results so far, I am sure I will need to consider different metering rods/main jets ultimately, probably larger secondary mains too...

how much vac is it pulling when its pinging ?

Ah, the $64,000 question! I didn't get a chance to look but I did think ahead enough to run a vac gauge into the cab, I just couldn't get a look at it fast enough to see it happen - next time I take a passenger along as an observer!

Thanks for the help Pat!