Pinging Timing

[clar]

I am running my gas millage tune and getting some pinging at low rpm . I have been turning the spark up 1% for the different rpm settings is this the correct way to remove the ping.

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[JackandJanet]

Originally Posted by clar

I am running my gas millage tune and getting some pinging at low rpm .
I have been turning the spark up 1% for the different rpm settings is this the correct way to remove the ping.

If "up" means "advanced", this is what causes ping. With the ignitions I'm used to, an over-advanced spark causes pinging under load (hard acceleration). At idle, an over-advanced spark causes an unstable idle - it sort of "hunts" and can't quite figure out where to settle.

But, I'm really a newbe to these PCM controlled spark curves. I only totally understand the mechanism in a distributor.

I've never seen ping at "low rpm".

I'd have to say though, if I were getting pinging, I'd reduce (retard) the spark. But, if it's a custom tune, you should be in touch with the guy who did the tune. He needs to fix it - it's not something you should be trying to "improve" on.

- Jack

[KR-Texas]

I have a slight ping under moderate acceleration with my 2007 FX4. When I took my truck into the dealer, they said they could not help me because I have an AF1 3.0".

I just ordered tunes from VMP, so I hope his tunes will not have the same issue. Is the timing normally adjusted with custom tunes or do I have to specifically tell Justin about it?

Thanks,

FX4-Texas

[CobraKit]

If its pinging, you should take timing out, ie -1 deg, not +1deg.

[Racing2Fast]

Originally Posted by KR-Texas

I have a slight ping under moderate acceleration with my 2007 FX4. When I took my truck into the dealer, they said they could not help me because I have an AF1 3.0".

I just ordered tunes from VMP, so I hope his tunes will not have the same issue. Is the timing normally adjusted with custom tunes or do I have to specifically tell Justin about it?

Thanks,

FX4-Texas

Aftermarket CAI's, can play havoc on these trucks w/ stock tune. VMP will adjust his tunes for the CAI, and you should be squared away, and with out issue after you upload the new tunes.

I have K&N CAI, and VMP tunes... Love them and Im w/o Issues!

VMP ROcks!

[ASEMechanic]

Most pinging or detonation will occur during low RPM / high load conditions, or "lugging" conditions. In such a case, adding timing will only exaggerate the problem. You want to either remove some timing via the custom adjustments or run higher octane fuel.

One thing to keep in mind is that most stations have switched over to winter-blended (oxygenated) fuels, not to mention that nearly everything is 10% ethanol now. Getting tough to get any good quality fuel anymore. Ideally, ethanol has a higher octane rating than straight gasoline but it just doesn't have the performance that I get with straight gasoline.

Ah well... in 20 years we'll all be running on hydrogen generators anyway.

[clar]

Thank you for your replys
I added 1 degree to timming ajusting my custom tune correcting that with a minus should fix the problem.

Even with custom tines you can tweak for your own custom prefrence.

Thanks for setting me streight on the plus minus ping issue.

I was ajusting spark @ different rpm settings what is Global spark for?

[ASEMechanic]

Global spark is as the name implies; It adds (or subtracts) a fixed amount of timing to the final timing calculation, regardless of RPM or load. This is sort of a brute force method of timing adjustments since it occurs after any knock, tip-in or fuel related timing calculation adjustments. I'd honestly stick to adjusting the timing vs RPM as this has a bit more control of how much timing you put where.

[clar]

Great reply Tks........

[KR-Texas]

Is there any rule of thumb for how much timing needs to be taken out to get rid of pinging? Or, does it depend on the exact configuration of your vehicle?

Also, I noticed the lower end RPMs only move in increments of -2, while the higher ends let you adjust by -1.

FX4-Texas

[JackandJanet]

Originally Posted by KR-Texas

Is there any rule of thumb for how much timing needs to be taken out to get rid of pinging? Or, does it depend on the exact configuration of your vehicle?

Also, I noticed the lower end RPMs only move in increments of -2, while the higher ends let you adjust by -1.

FX4-Texas

My rule of thumb is to apply the SMALLEST change you can, and then see what that does for you. I don't think there is any "set" rule.

In your case, I'd look at where pinging occurs (in terms of RPM) and I'd reduce the advance at that point by the smallest possible increment there and then test.

You don't want to over-retard the spark - doing that will kill your power, gas mileage, driving fun, etc.

- Jack

[KR-Texas]

Is there anything else that can cause pinging besides the timing? Gas with too much ethanol, poor quality gas, etc.?

I am using an 87 performance tune with an AF1 3.0 CAI and true duals straight out the back, 14" flow masters with 2.5" piping and an x-pipe.

I am at -12 for 0-2000 and -4 for 2000-4000 and -4 for 4000-8000. I still hear a very slight pinging just below 2000 rpms, but it is much better. I tried the following settings in order:

-2, -1, -1
-4, -2, -2
-6, -3, -3
-8, -3, -3
-10, -3, -3
-12, -4, -4

As you said, the power seems to be gone, but I am not sure about the gas mileage since I just started changing things this week. I am tempted to just go back to 0, 0, 0 and try some higher octane gas, but I was hoping to get some opinions before my next fill-up.


Thanks,

FX4-Texas

[Justin@VMP]

Poor gas quality can cause it, we are seeing that more often with 10% ethanol gas, and now winterized gas. Recently, I've see more of this than usual, so I think the winterized gas is effecting things.

KR, that is a ton of timing to take out.

[KR-Texas]

Justin,

I am back to 0,0,0 with the 87 Performance tune. If I run 93 octane the pinging goes away completely and the truck runs great. Of course, the reason I ordered the 87 tunes was to save money at the pump by allowing me to buy regular gas.

I also tried 89 octane and the pinging is much less, but still there.

You have several emails from me on this topic, so please let me know what I should be doing to get a better set of 87 tunes for my truck.

KR-Texas

PS. I live in Houston, Texas, so I do not think we get the winterized gas down here.

[JackandJanet]

In my somewhat long history of driving, I've always heard a very mild pinging under load is not harmful. If you're getting pinging under light acceleration though, something is not set right and the tune should be able to correct it.

- Jack