ls1_lover

Ping is pretty much everywhere under load. Not even WOT just half throttle or more gets ping from any speed. Maybe Injectors? Maybe Coils? Maybe fuel pump? The car has been to 2 mechanics. Both good guys but have no idea how to resolve this ping issue. I had new plugs, new wires. VAlley cover replaced. Two tunes already.

ls1_lover

Scanned car at idle. Let idle for about 20 mins. IAT sensor gauge in scanner software shows 126 degrees and climbing. ?? Is IAT bad??? Have I solved my problem???

ls1_lover

unplugged iat.. took her for a run.. same thing.. bad ping

ls1_lover

What does all this mean? This is from my scan.

Darth_V8r

iTrader: (4)

I don't think your IAT is faulty. If it were, you'd be pulling timing but not actually knocking. What's your coolant temps running?

mrvedit

As mentioned, an artificially high IAT value will reduce the timing with a stock-ish tune.

While you could reduce the entire High Octane Advance table by a few degrees, I'm inclined to agree with JakeFusion that "You have some other issues". This might include a cracked valve, cracked piston or something else within one combustion chamber. I would use an inspection camera through each sparkplug hole. Find a shop with one, or the $70 camera from Harbor Freight might be good enough. (I have used it for this.)

jaydubb

Take a drive and log it. Then post it here for us to view. Make sure you are logging knock retard...

ls1_lover

Problem solved. I would have been nice if just one person here gave me the answer but I had to figure it out on my own. And the answer is...

Coil Packs. Cylinder 1 and 3. Bad Coil Packs

ls1_lover

Coil Packs can cause a bad ping. It can start small with a small ping here and there. It can grow and get worse either quickly or slowly. I bought the HPTUNers software. Write Entire a stock tune. At the time I had no idea how dangerous Write Entire is. It worked. Got stock tune now. Ping, cant be the tune. Now what? fuel air, O2 sensor, MAF Map, this that and all the other sensors. Plugs new. Wires New. Vacuum leak, injectors, coil packs. Those three stick out as something to investigate. Put long screw driver to the injector listened for pulse. HPTuner tells me misfire on cyl 3, sometimes it says just general misfire. Move a coil pack 3 to 1 and sure enough, get misfire on 1. Bingo. I got a bad coil pack. Put new coil pack on cyl 1. Run scan and see misfire on 3. Oh ****.. this might be a vacuum leak. The misfie is traveling around. Replace coil pack on 3. Double Bingo. Problem solved. The thing is that I have to rewrite my tune that I got with the awesome tranny tune. Pumped the Tranny pressures up and it shifts hard and fast. This alone is like getting 40 hp. I have to write to the ECU one more time that old tune that I took off to replace with the stock so I can diagnose. I write using calibration only... and hope the settings take effect. They do. I dont fry my ECU, the car runs awesome. tracks straight, no vibration. I got 2 new coils and 6 old ones. Need to replace them all. One final note for you to consider.. a bad tranny tune can make the car shake like you have a bent drive shaft. A tranny tune is so important and Im surprised it is always engine tune , engine tune. Firm quick shifts are just as good as adding about 40hp.. I love this car more than ever now. I cannot wait to put the headers. Ohhh what a beast I lay with....

30thanniv

iTrader: (2)

David it can only get better from here. Great job dude!!

ls1_lover

Thanks David,

I learned a lot for sure. Now I wonder what air fuel issues I am going to run into with the headers? I have not adjusted the VE tables yet. Volume Efficiency. Im afraid to ask but can anyone tell me what I can expect when I put on a pair of texas speed 7/8 long tube headers.

pantera_efi

iTrader: (1)

Hi, yes great work as I too have had little experience with this failed coil.

I DOES PROVE the Dwell current sense logic CAN CAUSE AN EARLY Spark Instant.

I would like you to send me the two coils (USPS) AND I will test them with report provided.

Lance