Getting Started

Decipha's custom GUFX strategy covers all 89-93 foxbody ecu's including the 88 mass-air california ecus.
90Mustang
Posts: 6
Joined: 2021 Apr 27, 14:10
Location: Rochester Hills, MI
Vehicle Information: 90LX
393 TFS heads, intake

Getting Started

Unread post by 90Mustang »

I recently have my 393 combination together and need guidance to start the tuning. I input the parameters for my engine in the order stated in the A9L2 writeup. The good news is I was able to fire the engine on the first try following all of the good information on this site. The bad news is my 30 year old heater core started leaking as soon as the engine came up to temperature and made a mess in my garage. I was able to set the fuel pressure at 39 and the timing at 10 and now I need to work on getting the fuel correct. I have several questions and the main one is the best way to view the logs to understand what needs to be changed. When I try to view the dashboard while playing a log, the play pause buttons are in a separate window so it is very awkward to view and control a log during playback.

What is the best way to view the IMAF, hego1, hego2 and wideband together?
I have the AEM 30-4110 and the gage reads 1.00 while the log shows 1.2-1.3. What is the correct transfer. I selected AEM UEGO.
Why is the idle staying around 1000 rpm and the isc at 50%? I set the idle rpm in the .bin file to 850.
Based on this short log taken at idle, I'm not seeing closed loop and not sure why.
Attachments
idle1.xdl
(4.6 KiB) Downloaded 234 times
decipha
Posts: 4950
Joined: 2021 Feb 15, 12:23
Location: Metairie, LA
Vehicle Information: Work Truck
'19 F-150 3.3L

Re: Getting Started

Unread post by decipha »

hold down shift and press the [ and ] buttons above the enter key to move the log forwards and backwards

If you don't hold down shift it will jump faster for each time you hit the key

You simply view the data dash everything is on there.

Its not yanking the idle down cuz your idle is too erratic. It has to be over the base idle rpm long enough to begin reducing idle air and your engine isn't staying consistently over idle rpm for that to happen.

You can try grounding the distributor housing to see if it causes the idle to stabilize a touch more.
90Mustang
Posts: 6
Joined: 2021 Apr 27, 14:10
Location: Rochester Hills, MI
Vehicle Information: 90LX
393 TFS heads, intake

Re: Getting Started

Unread post by 90Mustang »

Thanks for the help and all of the good information you have provided.

I tried the distributor ground, but not any better. You raise a good point and I will next try to clean all of the engine block/ chassis grounds with scotch brite. I did use contact cleaner on everything, but maybe the grounds still aren't as good as needed.
90Mustang
Posts: 6
Joined: 2021 Apr 27, 14:10
Location: Rochester Hills, MI
Vehicle Information: 90LX
393 TFS heads, intake

Re: Getting Started

Unread post by 90Mustang »

The logs show I'm running really lean and I realized the wideband gage doesn't have a reading while the engine is running. I suspect my new AEM wideband isn't working. A call to AEM confirmed the sensor is bad and they will send a new one.

To make sure the engine is OK, I pulled the plugs and did a compression test. The compression is good, but I can tell from the plugs cyl. #3 isn't firing and there are several other cylinders misfiring. I have an MSD 6A box and coil which ran fine with the stock engine and the MSD distributor is the only new ignition component. Based on your comment about the distributor ground I started looking into why the new distributor could be the issue. It's very suspicious to me that cyl. 3 isn't firing since it is the second cylinder in the firing order. First, I changed the TFI module and it's still misfiring so I start looking at the other components in the distributor. I started comparing the reluctor wheel to the one I have from the stock distributor and noticed the 7 "teeth" have much more variation and the small tooth measures larger than the stock one. I put one on top of the other and visually there seems to be a small difference in the angle of the teeth. The stock wheel doesn't fit in the MSD unless I modify it so I have an accel distributor that I put the stock TFI and wheel into. Now, the misfiring is gone and the engine runs smoothly. I have purchased a new reluctor wheel that should be highly accurate and I will try it in the MSD when it arrives.

I have seen many recommendations to use a ford distributor and now I know why. I'm very disappointed with these aftermarket distributors. They seem to know ignitions, but they don't seem to know the design and importance of the other components used in these ford systems. The TFI, hall sensors and reluctor wheel are cheap low quality parts and those are probably the most important components in the EEC IV system.

Now as soon as I can get wideband and distributor back together I will continue with the tuning.
decipha
Posts: 4950
Joined: 2021 Feb 15, 12:23
Location: Metairie, LA
Vehicle Information: Work Truck
'19 F-150 3.3L

Re: Getting Started

Unread post by decipha »

thats all in my pre tune info I recommend you give it a read over
90Mustang
Posts: 6
Joined: 2021 Apr 27, 14:10
Location: Rochester Hills, MI
Vehicle Information: 90LX
393 TFS heads, intake

Re: Getting Started

Unread post by 90Mustang »

Yes, I have read that in the past and referred to it when trying to solve my issue. The problem now is it is difficult to find a 351 production distributor that is new or with low miles, motorcraft has stop selling the hall sensor and the motorcraft TFI modules seem to be low quality. I received the reluctor wheel and it measures spot on so I will try it next.
90Mustang
Posts: 6
Joined: 2021 Apr 27, 14:10
Location: Rochester Hills, MI
Vehicle Information: 90LX
393 TFS heads, intake

Re: Getting Started

Unread post by 90Mustang »

I have the AEM WBo 30-4110 and the scaling is different than what is listed. How do I change the formula to correct the value? How do I convert it to this 12800 formula from 0-5V? I have done the conversion and there is a few percent difference at Lamba =1. The value listed is 0V = 0.683, 5V = 1.264 and the values that came with the gauge are 0V = 0.683, 5V = 1.366.

Transfer Function:

A9L2: Lambda =(1.264-0.683)/5*V+0.683
AEM: Lambda =(1.365-0.683)/4.99*V+0.683
Attachments
AEM92 value.JPG
AEM value.JPG
decipha
Posts: 4950
Joined: 2021 Feb 15, 12:23
Location: Metairie, LA
Vehicle Information: Work Truck
'19 F-150 3.3L

Re: Getting Started

Unread post by decipha »

its detailed in the write up

http://www.efidynotuning.com/config.htm
90Mustang
Posts: 6
Joined: 2021 Apr 27, 14:10
Location: Rochester Hills, MI
Vehicle Information: 90LX
393 TFS heads, intake

Re: Getting Started

Unread post by 90Mustang »

Thanks, I couldn't wrap my head around the conversion to Ad counts.

So if anyone is interested, the transfer function for the current AEM 30-4110 is:

(0.1367*(x/12800))+0.683
decipha
Posts: 4950
Joined: 2021 Feb 15, 12:23
Location: Metairie, LA
Vehicle Information: Work Truck
'19 F-150 3.3L

Re: Getting Started

Unread post by decipha »

plx its already in there
Post Reply