mikes97

Hello Everyone,

I’m a new member to this forum. Chris (ravencr), Alan (Haveblue), and other members have been very helpful it getting me started. After some research I was hoping your experience can provide me with much needed help in the area of tuning. I have a 97 4runner that was pretty much stock except for the supercharger and a tranny oil cooler. After reading the threads, I decided that I needed to make the fuel upgrades to my truck to prevent the pinging. A few weeks ago I got a great deal on brand new normally aspirated Supra injectors and a used Apex’i S-AFC. I’ve installed these items along with a Walbro fuel pump, Autometer Air/Fuel Gauge, and a Split Second ESC1 signal conditioner. After some trial and error (and a few check engine lights), I’ve got the truck running OK. I initially followed Gadget’s advise by setting the low throttle settings on the AFC at -15% and the high throttle settings at -10%. The car’s check engine light would go on and white smoke would come out of the exhaust - I assume this was caused by a rich condition. And not having close to all the exhaust modifications Gadget has (except for the deckplate mod), I re-set the low throttle rpm setting at -19% and at -12% at high. The Hotwire type was left at 01 and 01. Low and High Throttle position was left at the AFC’s default setting of 10% and 50% respectively.

Here comes the questions (finally). Are my settings above about right (this is more for S-AFC owners that live close to sea level)? Without having immediate access to a dyno (I’ve made an appointment)...is there a way I can make sure that my car is the safe zone? The air-fuel meter seems to just dither between low, stoich and rich settings at idle and low speeds. Only upon boost or higher throttle application does the light change to stoich or rich consistently.

Next question, I seem to have a hard-start problem after the truck’s been driven for only a few miles and then shut-off. It takes 2 to 3 attempts to get my truck started again. Any reason(s) why?

Last question (for today)….after hard driving and sudden deceleration (exiting a freeway for example), the truck did stall once at a traffic light (very frightening experience – especially with a yelling girlfriend as a passenger). The S-AFC manual explains a feature that will prevent this but I don’t know how it works…do you?

Any help would be appreciated since my appointment with the tuner shop won’t be for a couple of weeks.

Thanks,

- Michael
magnomichael@aol.com

Gadget

These new Supra injectors, what was the part number on the side of them, what color are the tops and where did you get them from?

The feature in the AFC to prevent stalling, if that is called decel air, leave it alone it does not apply to a MAF system.

I asked about the injectors because there is a company out there that is selling injectors that have been causing some problems that mostly presents in a hot start condition. It also sounds like you are running very lean and the injector size may not be what you are expecting.

Those settings that I used to use on my AFC where with the stock MAF and 305cc injectors on my 96 truck and also worked perfectly on my 97. If you have 305cc injectors then those settings should work on your truck at least to a point where it will run properly.

Now as far as tuning, there are two areas to do your tuning, closed and open loop. Closed loop mode is best set up using a scan tool and tune the AFC so that the short term fuel trim is as close to ZERO as you can get it in all loads and RPMs except boost. You may find that you have to reset the ECU a few time to kill the fuel trims during this process.

You may find that setting the high throttle point to 30% will work better for you because it is at 30% where the engine goes into boost.

Once you get that all dialed in start on your boosted side. The best way to do that is with a wide band O2 meter and dial in the AFC to get the fuel ratio in the proper range.

I think you will find that a Split Second product called the ESC1 is a fantastic device to help the engine run well in low boost before it goes into true open loop.

Now I do have some bad news for you. Fuel mods really will not do much at all for the HG/LR-Ping problem. In fact they can make it worse. The HG/LR-Ping problem is an ignition timing problem. Retarding the time just slightly in the RPM and load range where it presents will cure that problem. This is why the Split Second FTC1-e would be the best choice for a controller for you as it will handle your fuel mapping needs as well as the timing retard needed and the ESC1 function all in one box.

If you decide you want to upgrade to the FTC1-E later let me know. I will have some instock in about a week or so at a discount to board members.

Gadget

www.GadgetOnline.com

mikes97

Hi Gadget,

I was hoping you'd reply (as my mods wouldn't have happened if not for your website). The injectors were the ones you specified (part # 23209-46031) with the burgundy tops I believe.

Now comes even more newbie questions....what, where, and how do I get this "scan tool" to begin the closed loop tuning?

I will change my high throttle point to 30% as you suggested....do I keep the low point at 10%?

The wind band O2 meter is my next purchase...actually I was waiting for the one you said you were working on.

I would love to upgrade to the FTC1-E, but you can understand some bitterness on my part after having recently purchased and installed the ESC1. Let me know how much.

Thanks for everything.

Michael