duplantisjj

OK...it started pinging a week after installing the whipple. In Alaska, we only get 90 octane fuel..yeah I know it sucks...but that's life...Anyway, I talked to Allen Nelson and told him of my pinging problem....symptoms:

Under light/med throttle, Aftershifting to 2nd...it lightly pings...almost sounds like a tick tick tick. If I take off from 1st really hard..I get no ping.......If I'm cruising around 40-50 in 3rd or 4th and hit the throttle a little...it pings...If I nail it ...no ping........If I take off slow it'll ping around 2K rpms

No octane booster and it pings worse. With Octane booster it pings less. I even tried $23/btl TORCO....still pings but not as bad.

Just got my 2nd tune back from Allen...and the ping is much less but still there around 2k rpms.

Spark plugs...I followed Whipples' instructions and got AC/Delco Platinum tip 41-932 plugs..$50 for a set!!........Changed to NGK TR6 and no change in pinging but the platinums lost their 035 gap and were at 050.....plus they were red from all octane booster (I hate that crap)

I also just got the AEM wideband from Allen and will install this week. I think I'm running a little lean around 2K RPMS....but the crappy NB autometer I have is not dependable (but it does show lean in that range when it's pinging).....

Fuel pressure sits around 50 at idle, 55 around 2K rpms and at around 60 at WOT.

I think HPTuners is next on my list for logging and ease of getting tunes w/o shipping PCMs back and forth.

Any other ideas??

TahoeSS01

What temp is it running when it pings?
Sounds like too much timing due to the lower octane.
Torco should do the job-at what level did you mix it?

Whats the AFR at that time-Need to be around 11-richer is better than leaner.
May be the maf-Try the old one

duplantisjj

It pings at any temp,,,cold or hot.....I have a 160 stat and it runs about 180.

I just got my wideband connected up today.....it's staying around 14.5 - 15.2 during idle and during the ping at 2,000-3,000 rpms.......the A/F seems to drop to around 12-13 at 3/4 to full throttle.......not sure if that's lean or rich.

I mixed torco at one can (32oz) to one tank of gas (26 gallons)....didn't seem to do anything....

Whippled 496

iTrader: (4)

12-13 is not specific enough, but either way thats to lean for a WOT pass. You will get a few different opinions, but at WOT you should have that AFR around 11.75, a little less is fine (Less is richer). My commanded AFR at WOT is 11.70 and my actual AFR varies from 11.6 - 11.8 at WOT.

TahoeSS01

The torco mix should have got you around 93 from the 90 octane.
Without a scanner to monitor the readings and timing at the time of ping
we can only guess at the problem.
12-13 is too lean-
That needs to be corrected with a custom tune along with the timing ?
Or get the HP tuners like you suggested
(The only other issue would be the knock sensors-GM had a bulletin out for
this issue . but you can "tune it out")

duplantisjj

My AEM jumps back and forth too fast for me to zero it in on a specific number. It fluctuates back and forth from 14.7, 14.8, 15.2, 15.3, 14.6, etc....all in the time span of a second or two...... Not sure that's normal on a wideband.....I have no way of pinpointing to a 14.7 or 14.8 number....unless I logged it into a data logger.

I contacted Nelson and he's shipping a retune since it is hitting a bit lean in the upper range. He says that around 14 or so is about perfect for low to mid throttle which is where I'm pinging. So maybe it's a timing issue.

dewmanshu

iTrader: (4)

make sure you are explaining this to Allen correctly, it seems you are contradicting yourself. Pinging at low to mid throttle or 3/4 to full?

as whippled said, lots of different opinions, but most will agree 11.7 is safe and a great place to be with FI at WOT or 75%TPS. "Around 12 to 13 at 3/4 to full throttle" on 90 octane or 100 octane with an afr of 13 is going to be too lean. You are in alaska, what's your air temp right now? Humidity? Holy dense air. There is alot too this, obviously to get 11.7 AFR you have to come down from 14.8 but is it fast enough? Is it really going down to 11.x? Get the software. Helps us help you and makes for tune swapping with Allen a breeze, once he unlocks the pcm .

Allen may be able to fix with just putting you into PE quicker, nevertheless, don't spend to much time in the 12's or 13's with lots of throttle.

duplantisjj

Yeah..I see what you're talking about....I just re-read my post.....probably should've written that better...

Between idle and around half throttle I'm hitting between 14 and 15 on the AEM wideband.....Allen said that was about normal at that range of TPS

Past half throttle on to full throttle I'm hitting between 12-13 on the AEM .....Allen said that was a bit leaner than it should be and was going to compensate the tune

Current temps in Anchorage are around 35-40 deg F.
I'm using Torco racing gas concentrate which should give me around 93 octane (if Torco is ACTUALLY doing anything)
Humidity is around 40%

Really strange...yesterday the pinging actually went away for a while...and the truck seemed to be a LOT more responsive...... Then it came back......

dewmanshu

iTrader: (4)

you have a low and high octane table. The pcm is trying to get rid of the kr, so it is "learning" your low octane table. So I wouldn't be surprised if that was the case on the less ping. I don't know what tune you have, Allen could have given you a tune where both tables are the same, doubt it. The reason it is more responsive is cuz it isn't pulling timing due to kr. He just needs to richen it up a little, he'll work it out with ya. you are in fairly decent hands, just don't do much wot or heavy throttle if you are in the 12 or 13's as far as AFR is concerned.

dc_justin

iTrader: (13)

How does the Wideband look with the stock MAF inplace (has a screen still, right?) vs the Granatelli.

I'd put money on the MAF being your problem.