skullandbones

I'm pleased to say I got my new computer system installed and started the engine with the new PCM and base tune that was sent with the kit. I was equally surprised to hear the engine come alive this time as I was when it started immediately on the first start of the EEC-IV setup years ago. As reported in the instructions the engine does not run very well at first. It requires some adjustments of some of the cells in the VE fuel table. There is only one of these with an option to put another in for what I am not sure yet. I will be reading about that soon. Anyway, there is a table for fuel that has 256 cells: each with a value which is a percentage of load at a certain rpm. Load is represented on the left (y axis) and rpms is represented on the bottom line (x axis). So each cell will have something like 40. If you change that cell to 50 you are adding fuel or going richer and less is leaner. Of course, the idea is to get the engine to run as lean as you can and still be safe from detonation and run with power. You have to get the engine to run well enough to be able to stay running and pull, at least, to a slow to medium cruise speed. It didn't take me much changing the cells to get it to drive normally. There were a few stutters and stumbles but for the most part it ran well enough to get up to speed. There is a "life boat" for new tuners as the literature calls it in Tuner Studio, one of the software apps that support this PCM. It is a "live tune" mode that has an algorithm which calculates the AFR (using a wide band AFR sensor/gauge to compare the real AFR values in the load/rpm ranges you are driving in on your VE fuel table. It changes the values of that cell as it moves through the load/rpm ranges. If that cell is not used in your driving scenario for that tune, it will not be changed. The object is to drive in every possible scenario that you will find to achieve the maximum number of cells changed in that tuning session. One of the tech gurus said not to worry since I have a N/A engine as only about 70 cells will ever be affected. If I had a power adder, it might be as many as 140 or so. But I can not create a load over 100% with a n/a engine. After I have tuned as many as I can with the auto tune, I work on the table manually so I can smooth the transitions from cell to cell to make it smoother running and looking on the table. This is a somewhat trial by error method but it does work. After about three driving sessions, I have gotten the tune to a point where it is as good or better than it was with the other computer. I know there is room for improvement and also there is capacity for improvement. Where as with the old computer, I did not have much if any tools to make the computer run better. At this point, I think I could take the roadster cross country. That's how well it's running. I still haven't done any WOT launches or red line shifts but that will come after I get back to it after finishing another project that had to be done. I can get into the roadster now any time and drive it without worrying if it will run well or not. One mysterious aspect of this process is the ignition portion. I have an ignition table form one of the Mustang racers who has an engine very similar to my setup. It was a two year development during two racing seasons. So I removed a couple of degrees as it was optimized for 93 octane which we can't get here. I'm thinking I might try a little more or less rather after I have my fuel table "perfect". However, I will not be doing much on it beyond that as there is not a lot I have found in my research that is intuitive about ignition timing adjustment. I will have to read a lot more and maybe get some books on the specifics to get some insight. The ignition timing is good though.

My next move is to disassemble my intake and install the new ITB setup (8 down draft 52 mm TB). I should probably wait for the heads which I am porting (cleaning and smoothing mostly) but they are not ready so I guess I will be going thru a few sets of gaskets before it's finally done. After I am reasonably sure I have the ITBs right, I will be going to a DIS (distributorless ignition system). This is one of the major reasons for me changing the computer as it will support multiple setups for induction and ignition with a little user input. I don't want to change too much at once so I got the new computer started with the engine setup exactly as it was with the old computer. One change at a time will reduce the variables for trouble shooting. It also keeps me busy! (ha-ha).

As I said, the engine is running as good as it was before the change but it gives me hope to be able to tweek the tune for those extra hps that were left out of the EEC-IV by the Ford engineers. I will have to see how much I can squeeze out of it. The other cool thing is you have literally control of every aspect of the engine management with the touch of a computer key! Maybe that's a little scary in some ways but also very powerful tool when you learn how to use it.:cool::cool::cool:

Thanks,

WEK.