Haltech Tune Issues

[Calibrator]

Its common for mixtures to change fairly drastically like yours is doing depends on cam intake manifold etc. You will have to fiddle with the mixtures till the bucking goes away and live with the rich mixtures at some point. I would start with the 1500rpm site.

[Jason Broadhurst]

Really its that common? The carbi used to run a 14:1 from idle to 7000 on primarys and it didn't have a problem. The bucking did go away with a 12:1 on both 1500 and 2000 rpm ranges but that cant be a genuine fix?

[buz81]

do you have any data logs from the haltech when you were having trouble?

[Calibrator]

[QUOTE]Really its that common? The carbi used to run a 14:1 from idle to 7000 on primarys and it didn't have a problem. The bucking did go away with a 12:1 on both 1500 and 2000 rpm ranges but that cant be a genuine fix?
[/QUOTE

You probbaly have fairly different numbers in the 2 maps at that point when you move off the dead centre of each speed range the processor starts intoperlating the values.
In your case halfway is more than likely a number not suitable for whats happening in the motor.

How big is the jump in your injection values between the 1500 map and the 2000 map? What is happening with your ign timing at that point?

[Datto-Zed]

"Justin Wangburner"! How the fuck did you get that nickname!? :D

[Jason Broadhurst]

I dont know, and as bad as it is, I only dont like it because people might mistake me for you :p

[PLAYA]

my tuner had to redo a few haltech looms because of interfierence for exact reason.

[Jason Broadhurst]

should interference show up on a data log though?

[Jason Broadhurst]

Alright, it seems ECU specific. When I remove spark from each cylinder it still gets worse between 1500-2000 rpm.

http://turbocharade.kicks-ass.org/fi...%20datalog.xls
http://turbocharade.kicks-ass.org/files/RPM-log.TXT

The spreadsheet is of the rpm and inj duty, showing roughness at the area in question.

The TXT is the raw data from the haltech.

[buz81]

should interference show up on a data log though?

Yes it should show up as a weird reading. I noticed a few of these when tuning evilchief's liberty.

It looks to me that the trigger signal is not working very well. I am guessing you were trying to accelerate not create the spikes. This could happen because of the ignition, trigger wire or the haltech

[Jason Broadhurst]

It does seem that there is a small inconsistancy in the rpm. The trigger is negative earth, and it is unclear whether the rough rpm logging is the cause or just the symptom of a fault in the ignition.

Oddly, if I run a fat mixture, the problem goes away, but anything over 13:1 and it is there. The more it heads towards stoich, the more prominant the problem.

What do you lads think? I am going to have to get a CRO on it I think.

[Datto-Zed]

Jason: I have a CRO sitting at my parents place you can have (for the forseeable fututre anyway). Gimme a call if you want it.

[Jason Broadhurst]

The jumping rpm is a symptom on the datalog, because the car is bucking around it logs rpm inconsistantly.

I threw a analyser on it and the tach feed was perfect.

Time to consider ignition problems then.

[Rollin]

What injector timing values are you using? If they change drastically around that rpm point that may be the cause of your problem?

[Jason Broadhurst]

They are consistant durring the problem, as the graph/logs show.