Hitting Wall At 5000 RPM

[scott30]

I took my car in the other day for a dyno tune and the tuner kept hitting a wall at 5000 rpm and has no clue as to why it is happening. I am no tuning expert so wanted to come here for advise/help. Car is a 97 z28 with a 383 lt1 with a F-1A Procharger on it and the car is utilizing the 24x conversion. Attached is a couple log files and the tune that was left in the car. Any help would be great.

Scott

[joecar]

From the log files it looks like fuel gets cut off (compare where RPM drops relative to where IBPW drops).


Look at B3306, B3305.

[scott30]

I exported the data and was able to see where the fuel gets cut off at. I looked at the tune last night and saw B3306 was the only thing that had 5000 rpm in it but since the ECT was 84C during the run and B3305 has 0 seconds for 80C I didn't think that would be cutting the fuel off. I can adjust the values in B3306 and see what it does.

[joecar]

Not related:

set A0012, A0013 to 511.

[scott30]

Will do. Thanks.

[BLK02WS6]

Let us know if this works... I was also going to suggest B3306 - I know it shouldn't be doing it, but it is the only table I could find that could. I saw that ECT was reporting, but wonder if there could be something up there - are you running the LT1 ECT sensor wired to the PCM harness? Don't really have any experience with the 24x conversion, but always wanted to work with one...

[scott30]

I will report back if it corrects the issue. I should have time to try it out this weekend. Like you pointed out I wouldn't think it would cause this but it was the only thing I could find as well. It is the LT1 ECT wired to the pcm. I bought a new harness from EFI Connections. The 24x conversion is a nice feature for the LT1.

[slow67]

I know on some computer systems changing a setting like that to "0" enables it all the time.

[rally1]

Did you get this sorted? The map drops at the same time as the fuel, it makes it look like it may be belt slip on the charger... the drop in map will cause a big drop in fuel..