Inconsistency
 

Is it possible for a converter to cause an issue where my car will make 3 or 4 passes within .04 of each other then out of nowhere make a pass that is .2 slow. On the pass where is slows down it loses ET everywhere starting with the 60'. Everything has been changed on the car trying to solve this issue, wiring, MSD, coil, fuel system, etc... I am of the assumption that if something was wrong in the converter it would continue to slow down, where as once I load up after making this slow pass, the next time to the track the car is right back to making good passes.

3000 lbs car
540" BBC
Ladder Bar Rear Suspension
Powerglide

I installed a data recorder to track engine RPMs this past weekend and on the two passes where the car fell off, the RPMs are very shaky from about .07 into the run. I will try to post a picture of the graph later.

Re: Inconsistency
 

post up all the time slips in order from the day in question.

That said, moving .04 in 3 or 4 passes is a problem no mind 2 tenths.

Consistency starts and end with the one wearing the brain bucket. Are you doing everything exactly the same from the moment you buckle your harness to the moment you cross the stripe?

Re: Inconsistency
 

Too rich makes it too sensitive to temp and Baro changes.

Re: Inconsistency
 

I pay extra attention to my routine for consistency, especially since these issues have come up.

I have the RPM graphs saved as pdfs but am not sure how to post them.

I do not think it is jetting just for the fact that no big change in weather has to happen for the car to make a slow run. No matter what the weather does the 4th or 5th run will be .2 slow and if we make any additional passes after the slow run they are slow as well.

Re: Inconsistency
 

again, post the time slips in order from one day.

Re: Inconsistency
 

Had a car do that once, had one broken roller in converter sprag.

Re: Inconsistency
 

Targus, In the submit reply window, top row, there is a paper clip next to a smiley. Right click that & a window opens with a button to browse your computer for the files you want to upload & in the lower right of that frame an upload button. That said, I have never been able to upload a .pdf, only a .jpg or .bmp. Can you save the file differently ?

1320, how bout we help with his upload issue 1ST. :D

Re: Inconsistency
 

Attached are RPM graphs with the red line showing a "good" pass and the black line showing a "bad" pass where is slows .2

Re: Inconsistency
 

I haven't had the privilege of reading many of these graph's but with the black line rough, does the engine have an intermittent miss ?

Re: Inconsistency
 

There is not a noticeable miss. With the lower stall of the converter you can feel that it is on a lazy pass. The up and down movement in the black line equals about 100 RPM.