I am again attempting to get some hands on time with my very old system. It's a FAST classic box, sequential. I noticed that both the after start enrichment and the warmup or temp correction tables show the little circle at zero whith key on but engine not running. When the engine is running they both show the circle at the top of the graph. I wonder if there is something out of adjustment, that I'm not aware of, or is there something wrong with the box?
Classic FAST questions
- Thread starter TomShea
- Start date
I just purchased a classic fast and I know very little at this point. It sounds like temp/after start enrichment is not operating until the computer sees rpms.
I quess I wasn't clear enough. The after start and temp corrections are both at zero with key on and engine not running. This is as it should be.
With the engine running the after start enrichment and (warm up enrichment) Temperature correction both show the tiny circle indicating the horizontal and verticle line intersection like a bulls eye, is maxed at the top of the window.
There is obviously RPMs when the engine is running. This bull's eye placement is not as is should be. The bull's eye should be at the user selected line of the ramp for the target programmed. This is usually no where near the top of the screen.
I don't see any indication of extra enrichment. The A/F is where it should be and the unit is correspondingly correcting at closed loop depending on the changes I put into the VE table.
My question is if there is some known reason for this. Maybe a setting that is incorrect, or is this an indication of the box malfunctioning?
I guess this may be a question for Craig Smith or Cal Hartline. Maybe Jay Carter. Someone who has experience with the "Classic" box. I have a little experience with tuning DFI and FAST and even a bit with BS3, but obviously I am not familiar with this particular issue.
Sorry about the misunderstanding, so your x and y values are pegged?? (bullseye in the upper right??) I'll be curious to see what answers you get on this one.
Actually the vertical line is positioned correctly and moves across the screen with the temp. It's the horizontal line that is at the top when the engine is running, where it should not be. The horizontal line should run across where the bulls eye (Cross Lines) rests on the user programed ramp line and slowly move down as the ramp line is traversed. This is on both of these screens, exactly the same problem. Seems a little coincidental to me. I don't see that there is a problem with the A/F ratio, since it seems to be where it should be according to the VE numbers. Also the closed loop is correcting, verified by me changing the VE numbers slightly and seeing a change in the O2 correction. I'm not sure if there is some other problem that I have not yet observed. I'm hoping to be able to either run it like this or maybe there is some setting, somewhere that is not right. I looked through the set up and global and did not recognize anything wrong. Still I may be overlooking something. I believe this particular, specific problem does not represent a malfunction other than the read out. I was hoping there would be someone else out there that had a similar experience. Maybe there is a way to test? There have been times in the past I have worked around other malfunctions on other boxes. I remember wiring around fuel pump controls and fan switches on other boxes, and they seemed to function normally other than the specific handicap.
Well this afternoon a friend stopped by. He reminded me about something that I pointed out to him a few years back, when he first got a classic FAST box. I'm embarassed to admit that I forgot this. The dash selected for the readout has to have the temp correction as one of the selected options. When I did this I was then able to view the little bull's eye in the proper position. Thanks to Roger Flint for pointing this out.
I am referring to real time viewing of the data. Not data logs. With my Sequential FAST box as well as at least one other, it requires the specific dash to include the temp correction in order to be viewed correctly. That is with the cross hair (Bull's eye) in the proper position. That is at the user set tune ramp line instead of at the top of the graph. This is for the 2 above mentioned tables. After start correction and temp correction (warm up enrichment). I don't think the dash even needs to be in view, but the temperature correction has to be included as one of the dash selections in order for the display to work correctly.