ls1_lover

2002 LS1 Camaro SS 460LE Runs like crap when warm outside. It will ping under load just about anywhere in the RPM Range.

Cold outside and runs like a beast. Im taking like a temperature difference of say 70degree to 80 degree. Cold outside. no pinging anywhere. Hot,, all over the place.

Why does the ECU not correct for this difference by adjusting the AFR? I am running closed loop.

Could it be that my MAF or MAP sensors are bad? I would love to fix this Ping issue once and for all. When this car runs good she is super FAST. When pinging it is like having a hot girlfriend that you cant have sex with..

pantera_efi

iTrader: (1)

My first step would to connect my laptop OBD cable with GUI.

You may not have a "scanner", today, this weekend, Harbor Freight has a GREAT sale, I believe this tool is included.

I just bought ANOTHER, limit five, batch of Battery Tenders @ $5.00 each

There was a FREE shop LED light added to my bag when I provided that add.

Lance

jhshnh

A bad tune with too much timing in the mid range that puts the car on the brink of detonation caused my car to run similar to what you're describing.

I then had Frost tune it and it was a major improvement.

nine8ss

iTrader: (5)

I would start off like Lance said with a scanner. Without actual numbers, its tough to diagnose "its hot and it pings". Check your IAT readings and see if they are near the actual temp. A bad IAT will throw off your timing and cause pinging and a loss of power.

tug686spd

iTrader: (11)

Since Harbor Freight was brought up here, I'm sure most people already did this but for those that havent text "TOOLS" to 222377 and you'll get 20 and 25% off of one item codes a couple times a month. It better than their Inside track club for me.

ls1_lover

My HPtuner.com software and obd2 connector arrive tomorrow. 500 bucks and now I learn that I really need to get an adapter for the wide band sensor. One that I stick in the exhaust. Software is going to come. I get some runs logged and come back here to see what we think. Right now I have a hunch, it is running rich. Pretty simple, Hack the map and flash. The thing is I cant make the adjustments to the map in real time. Guessing is going to be pretty hard. Am I missing something?

mrvedit

Generally the ECM leans out the mixture as the temperature goes up and and a lean mixture is more likely to ping. Since you have HP Tuners on the way, there is no need to guess at this...

Learn how read your existing tune and post it here. Tell us all engine mods, cam specs, etc and we can try to diagnose it.
Or is the engine and tune stock? We really need more information.

ls1_lover

Rodger that MRV edit. Engines only ping when AFR is lean? Then that blows my theory up as when cold outside no ping. cold outside means more 02 or lean. So Im not pinging when lean. However, Hot weather means less 02, more gas means Rich. I am pinging when my engine conditions are rich. Engines never ping in Rich condition? When would an engine ping in rich AFR ? There must be a case..

So first Im going to hook up the scanner and get AFR as close to perfect using the map. If I still ping then I look at the spark.. timing.. is this correct.?

JakeFusion

iTrader: (7)

No, what mrvedit is saying is that if the IAT reads high temps, it leans out the mix. I've watched it happen on my scanner many times with idling on a 55-60 deg day and the IATs go from 60 to 100 in traffic with an SD tune. I'll go from 14:6:1 to 15.8:1 with the IAT change (in Open Loop). Of course, the sensor is heatsoaked and the air coming in may not actually be that hot. Warmer air has less oxygen in it - so that's why the PCM leans out - less fuel to keep from running rich - but with a heatsoaked sensor, it exaggerates it and leans it too much.

But in terms of actual physics and not GM PCM physics with possibly bad sensors, you do run leaner in cold weather as there is more oxygen in the mix vs warmer temps. But the motor adjusts for this and pulls fuel in cooler temps. But cars always make more power in cooler weather as denser air with more oxygen still makes for the best boom.

I try to tune my car when it's around 70-75 degrees (so summer nights or fall/spring days) so I don't have the PCM having to adjust for 80 degree swings. I see 88-92 in the summer and I don't drive if it gets below 55. So I adjust in the middle so my fuel trims are within about 5% all the time.

ls1_lover

so my know may have to do with a bad IAT sensor? It may have nothing to do with advanced timing?

ls1_lover

What I mean is could the pinging be from just a Bad IAT sensor?

I guess once I start using the HP tune software I can see what the IAT sensor is reading and just compare it to ambient temperature?

pantera_efi

iTrader: (1)

Hi, the "art" of HP tuners is NOT easy to understand.
DON'T even bother to call them for tuning help/tec support.
The best way is to find a dealer you can trust, one who is local.

I am respectful of your choice, a $500.00 purchase.
How many credits are in your cable ?
I will help you with HP Tuners.

The MAT (IAT) sensor IS the first direction, "reduce" it's authority.
I agree with the above IAT "tech".

I DO NOT agree with the AFR direction, though it is of concern.
The GM calibration is a low advance strategy, with near "stoic" AFR used to keep the TWC at operating temperature.

DO NOT increase the fuel amount to an OVER RICH condition (11:1), you will melt the piston crown/sparkplug ground strap.

Lance

Darth_V8r

iTrader: (4)

To be honest, this sounds like the car was previously tuned, and the timing was turned up. And IAT spark table was zeroed out. When IAT gets hot, the ECU will normally cut timing - unless this table was zeroed out. And your PE settings might also be out of whack. The issue could be too much midrange rpm spark, but once it starts, it keeps doing it.

You might need a colder spark plug in hotter weather too.

I can think of tons of mechanical explanations that would generally only be true if your engine is no longer stock.

ls1_lover

Some very smart people here. Your generosity is truly appreciated.

ON my 2002 Camaro SS that pings..... I took care of the plugs and wires. I

I got rid of my PCV setup and put in the LS6 valley cover.

Cleaned out the MAF really good.

I can see there are more than a few very smart people here. I am humbled to be in such great company.

The car has been tuned. MOre than once. Yes, it is a challenge. But one that I will enjoy.

I love this Fbody. They simply dont make them like this anymore. So here is my approach.

Record the short run where the car pings. Usually a WOT pull starting from about 2500 to 4000. Trap this data save the file and put it up here. I will first look at the IAT to see if it is reading correct temps. Then adjust the AFR in the cells on the VE Map where my run recorded enough data to make an adjustment? Get AFR as close to perfect as possible. Most likely, the ignition is advanced so I am firing early. Retard the ignition by reducing the crank shaft angle. Am I on the right track of thinking??? .

Thanks so much! My End goal? Turbo this bitch ??

mrvedit

Since your PCM was tuned, your first step should be to read your tune and post it here.
Since you are running closed loop, changing the VE table won't do much.
In theory, with closed loop the AFR should remain at stoic until you enter PE mode at high throttle. Which brings up the PE table - absolute max power is often reached with an AFR around 13:1, but only a tiny bit of power is lost at e.g. 12.8 which is less likely to ping.
Also, the timing advance might be at the absolute limit - on a hot day the air and fuel might be enough warmer to cause the ping; this is one reason the mentioned IAT spark table exists.
So post your tune and the experts here (not me) will likely be able to suggest a slightly more conservative tune to eliminate the ping.

Also, the knock sensors usually detect the ping, before it becomes obvious, and reduces the advance. This safety feature might have been eliminated in the tune.

ls1_lover

Is it crazy difficult to get rid of my OEM ECU and put in a new aftermarket one that allows me to make adjustments in real time?? How difficult is this? How much would it cost?

UPDATE: Car pings today during cold weather. So this car just pings all over. I replaced the Knock sensors when I did the LS6 valley cover swap. I was not getting any error codes but I saw them in there and just thought it would be a good idea while we had them uncovered. Changed the sensors and cables.

And about the Knock sensors.. Knock sensors only stop a "Really Bad" knock from destroying your engine.. Small knocks, or medium knocks like what I have the knock sensor will allow? Because my engine knocks. I hear it in the cabin but I dont really feel it like getting hit with a hammer. Is there an allowable knock limit? I cant wait to fix this issue so I can enjoy the most of this wonderful car. It is a blast to drive when she is healthy.

Firebirdmuscle

iTrader: (16)

With hp tuners you can tune in real time. Although I personally haven't done it nor figured it out but the capability is there.

First thought definitely sounds like to much timing in it

Darth_V8r

iTrader: (4)

It's knocking for real so don't worry about an ECU swap. Also, knock sensors react to knock you as the driver can't hear. They are typically too sensitive - unless they have been turned off in the tune. they're microphones. Settle down and don't throw parts at it. The knock is real, so start with things that actually cause knock.

Now, easy stuff. Spark plugs. Swap in a set of TR6 plugs. Then test drive. Is it better, worse, gone, or no change?

Fuel - what octane are you running. If you're running 87 octane on a modified engine, go to premium gas. If you're already running premium, switch brands and see if it helps

Carbon deposits - run some fuel system cleaner at triple the recommended strength and see if that makes any difference.

Now, the moderate stuff. Read your tune and post it. Lots of us on here know what is reasonable spark timing, PE settings, knock settings, etc. by the way, who did your tune? There are some notorious tuners out there who have blown up their customers engines.

Do a compression check. Normal compression cranking would be something like 165-200 psi. If you get a ridiculous number like 220 psi, read on for the hard stuff

Hard stuff - degree your cam. If your cam is installed on the wrong intake centerline - particularly if it is advanced, it will act like a very high compression engine and knock quite profusely in mid rpm range. Honestly this is my suspicion, but there is one other thing you need to do for us:

Post your engine mods. Internet diagnosis is difficult, but even more so with insufficient information. You've got to tell us heads, cam, compression ratio, etc, or even just that the motor is still stock. But something.

ls1_lover

The car has SLP loud mouth 1 catbacks. Thats about it. The only other thing done to it is the LS6 valley cover change over to get rid of the LS1 PCV design flaw. Other than that this beast is stock. The tunes? I bought it from a guy who got it tuned but I did not know that when i bought it. Then I brought it to SS Performance in Miami. Good place and they tuned it but I can see that a guy who owns a shop that does service and blot ons does not really have the time to spend on tuning a car. The owner there took it on a few short runs but that was it. I can see that to tune these you really need to spend the time. He does not have that time and I do not blame him for this. SS performance in Miami is a good shop. Plugs have been changed with OEM parts. Fuel, I always put in 93 but I do have a suspicion that CHEVRON 93 octane is better than the Shell brand. I have to go through my tank of gas to verify this. Carbon Deposits, When I had the plugs done the mechanic ran some seafoam through the engine. What about the Injectors? 92k on original injectors? Should I just replace them or can they be checked with the HP tuner software? Compression check, I think to late for that as I should have done that when I did the plugs but to do it now I have to remove those darn #7 and 8 sparkies. this car is stock. No mods to the engine or drive train. I want to mod it but first I want to resolve this ping. I should have the HP tune software tomorrow. on Wed I will record some runs on my way to work. Thanks again for all you that have responded and share the Love for these fantastic machines. Based on your knowledg and support I am confident that we will get to the bottom of this.

Darth_V8r

iTrader: (4)

Thanks, that's very helpful info! You wouldn't need to check every cylinder for a compression check, but since your cam is stock, it's likely installed correctly at the factory (99.9997% certainty). If you checked number 1, and it's in the 165-200 range, you can cross cam timing off the list. Also, your injectors are very likely fine. When you take the logs, if your fuel trims are severely positive, that would tell us that either the injectors are faulty, or more likely the fuel pressure is falling off. By the way, add a fuel pressure check to the list. My bad, should have included that in the first place.

So, really what we are back to is most likely your knock sensors were desensitized and the timing is likely turned up a bit too far. Don't forget to read the tune and post the tune as well as the logs.