I have learned alot in the last two weeks, and some of it might be of use, or interest to our slanted friends here.

The car is getting more user friendly, and better manered but is not up to power yet. At least I can drive it now.

1. The engine was dying when I let off the throttle, because the highest rows of MAP value cells in the fuel map were too rich, and blowing out the spark. It would come back with a bang as soon as the spark plug would dry off. I leaned the top two rows out to minimum values, and the car quit dying upon release of the throttle, with subsequent backfire when all cleared.

2. For some unexplained reason the starting prime pulse was turned off in the system configuration. This made it hard to start. Turning it back on fixed that.

3. The idle was surging because the idle cells in both the spark map and the fuel map had different values in adjacent cells. The engine idles in four cells, and it kind of floats from one cell to the next in a circle as it idles. If the timing is not the same in these cells, or if the VE value is not the same in the Fuel table, then the idle hunts up and down as it moves from cell to cell. I timed all the idle cells at 17 advanced, and put the same VE coeficient in all the idle cells, and things smoothed out.

4. The engine is running very lean under boost, hence the low power. To control the preignition that happened, the timing was retarded to almost 0 under full boost. Not enough fuel, and not enough advance created very little beneft from the turbo. Since the VE table already had the mximum allowable VE coeficient in the table under boost, it seemed as if there was no way to get more fuel under boost. I learned from Eli, at Accel how to enrich the fuel tables under boost. There is a multipler, called "TRIM" avialable for each MAP value in the table which can be entered in a seperate cell off to the side. This can take all the numbers in that row of cells, and multiply them by the "TRIM" number you put in. This then will supply more fuel by lengthening the duration of the injection. It sounds complicated, but it really is not. When you put the trim number in, all the VE numbers in that row of the map are automatically adjusted to deliver the same fuel as before. So you then have to go through and modify each cell as you tune it. Why Total Performance did not do this instead of lowering the timing, I do not know. Anyway, I now have the tools to get more fuel, and then increase the timing advance to get this engine running right. It should put out about 250-275 HP instead of the tepid 160 it is now doing.

Eli at Accel has been great! He was the missing link. He has provided what none of the other resources could provide: the dealers, the tune shops or earlier tech support guys at Accel. I hope Eli sticks around. When I first told him what the dyno numbers were on the turbo charged slant, his initial comments gave me a glimmer of hope. " Somethin' ain't right!" Now there you go! DUH! Music to my ears, and an attitude of caring and responsibility! I intend to write a good letter to his boss. I'll keep you informed.
Sam.

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Hey ! thanks for posting this stuff! I have this problem in my Sub and see your solution as a new approach to a small annoying issue.

Stay with it Sam.

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Yeah....Im the one who destroyed this rare, vintage automobile.....

Thanks for sharing that. I'm just hitting the tuning stage in my buildup now, so that may be useful if I run into similar problems.

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"Mad Scientist" Matt Cramer
'66 Dart - turbocharged 225
My blog - Mad Scientist Matt's Lair

The latest advice is "change only one thing at a time". I went out and changed the entire timing map, and fuel map, and it doesn;t run very well at all. I will go back to the old file, and start again. This time I will work on getting the transition from naturally aspirated to boost smoothed out, which means only dealing with one row of MAP cells, and then work my way down the map. I think I need to bite the bullet and do some data logging as well. It is really hard to do this flying solo, as too much changes too fast. The thing is, if you change one thing in a way that makes it worse, then you know right away which cells are wrong, and you can just go back the other way. But if you change too much, you are kind of left scratching your head and saying, "Now what?" Start over is what. Alot of time spent learning how not to do it.
Sam

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