Hello guys,
I know this topic has been covered here before but I feel like I've eliminated all the variables. After many forlorn attempts to resolve my high-gear/low-rpm pinging, I'm turning to you guys for some wisdom. Let me provide some history in hopes that there is an obvious solution I'm missing.
The problem:
I'm experiencing pinging around 2000-2400RPM from medium-throttle to WOT in 4th gear. It also pings easier when driving up a hill. I've read other members having this same problem and tried their solutions. I will expand on this later.
The setup:
1999 SR5 4x4 5-speed.
Stock pulley
7th Injector kit
Stock gears (4.10 I believe) and wheels/tires
Background:
After checking out all the information about supercharging the 3rd gen, I just had to get one. I found one for a really decent price on craigslist here in San Diego a few months back.
I ordered a 7th injector kit + plx module + wideband 02 sensor from Gadget right away. I didn't want to have a poorly running vehicle with potential long-term damage. The installation of everything went smooth but took a long time.
Unfortunately I didn't purchase/install the monitoring equipment until after I installed the supercharger; I'm new to this. The 7th injector kit and default map from URD seemed to help make the truck run better but the pinging was still there.
After setting up and familiarizing myself with the R4 tuning software and URDs u-tune guide, I modified the ignition timing adjustment range by modeling the values after this post (
URD 7th Injector install). At the time of that post, paddlenbike was running the same setup as I am now and lives in a similar environment. I realize that all trucks are different, I just wanted to get close and then tweak from there. I'm realizing now that the original tune was probably close enough and I have something else wrong. When I uploaded the new map, I did notice a difference how the power changed when transitioning to WOT high-rpm range. However, the original pinging problem is still present.
Next, I changed the fuel filter. It was cheap and easy. It was a little dirty but that didn't fix it. It's also worth mentioning that I am running the highest octane gas I can buy in my area (91 octane).
I'm seeing the AFR stay very close to 14.7:1 even when boosting. Strangely sometimes it was up around 16.5:1 when at 2.5psi.
A few days ago I re-read this post (
URD 7th injector tuning maps) and paddlenbike mentions he tapped the O2 wire instead of intercepting it before the ECU. The difference is essentially the California versus the Federal wiring diagram. I originally wired my calibration unit using the California wiring instructions because I have the California model emissions sticker under my hood. Based on the wide variance of information I've been gathering, it was worth a shot for me to rewire the calibration unit to see if the supposed closed loop enrichment feature would work. Also, judging by my data-logging (and the u-tune guide) I was convinced it should be wired with the Federal instructions (intercept instead of tapping the O2) because the AFR wasn't changing at all in closed loop mode (maybe I'm getting this wrong -- I haven't hooked up the R4 tuning software while driving to where it explicitly tells me which mode I'm in, I've been logging and reviewing everything else though).
So this evening I rewired as such to no avail. The truck runs nearly the same. This time the data-logging was a bit different. It AFR was richer than I've seen it even though it was only at 13.2:1 which doesn't seem rich enough.
My understanding is that the truck either needs to have its timing retarded or I need to add more fuel. Since the "closed loop enrichment feature" doesn't appear to be working I should probably wire the unit back to "Cali-style" and crank-up the values in the RPM/psi range where the knocking is occurring to retard the timing.
Sorry for the long-winded post. I'm getting a bit discouraged at this point; Eventually the goal is to not have to drive around the pinging; I'd like to just roll on the throttle. I still have a lot to learn regarding tuning but something else doesn't smell right. Did I forget something major? I should probably find a buddy to drive while I stare at the tuning software. Additionally, I don't believe I cleaned the MAF when installing the supercharger.
At this point I think I'm going to rewire it back to California emissions. I'm going to clean the MAF. I'm going to crank-up the values in the RPM/psi range where the knocking is occurring to retard the timing.
Am I in the right ballpark?
I should also mention that I did following (some relevant, some not) when installing the supercharger:
- spark plugs (Denso Iridium IK22)
- plug wires (factory Toyota)
- cooler thermostat
- cleaned the throttle-body
- replaced the PCV valve
- oil
- oil filter
- air filter
Are there frequent 4-Runner community meet-up groups in San Diego? I've felt a bit disconnected with this entire project. I even tried to make it "worth someone's while" by calling around town (SD Truck Shop, etc) and no one seems to know any shops that can tune my truck; I feel like I exhausted my options and subject knowledge. I know I have a 5-speed 4x4 but my truck can't be THAT unique. I know I'm really close to having everything dialed in and I'm looking forward to finishing this part of my build. Many thanks for any advice.
-Tyler
Linear Mode
