Steve's Megasquirt/tunerstudio Help Thread

[twohawks777@cox]

Upon cold start, accelerator can not be released or car will die until it warms up. Car serges thereafter for several minutes until it reaches about 120*-140*. Car apears to be running rich. If I take the car to 3000 RPM it backfires.When car reaches about 180* the RPM's are slightly 900-1000, but runs steady. Occillates ever so slightly. Car stumbles and pops when reaches 10 on the TPS gauge, but smooth thereafter..

 

[a91what]

Upon cold start, accelerator can not be released or car will die until it warms up. Car serges thereafter for several minutes until it reaches about 120*-140*. Car apears to be running rich. If I take the car to 3000 RPM it backfires.When car reaches about 180* the RPM's are slightly 900-1000, but runs steady. Occillates ever so slightly. Car stumbles and pops when reaches 10 on the TPS gauge, but smooth thereafter..

Ok I will reduce the warm-up enrichment this should help considerably. Now once it's warm idling what is the AFR? Remember that 14.7 is stoic or a perfect burn, below this is richer and above is leaner.
11.8-12.3 is boost
12.3-12.8 is wot N/A
13.4-14 light acceleration
14.4-16 cruise
Idle can fall anywhere between 13-15
These are just rough guidelines each engine wants something different.

I'm uncertain how much you know about tuning so forgive me if I come off harsh or if I overexplain things.
Patience is key once we get this sorted out the tune will progress quickly

 

[twohawks777@cox]

Thanks. Car reads between 14.7 and 14.9 at idle when warm. Trying to learn much as possibly. I basically turn all the wrenches on my car and only have a mediocre knowledge on tuning. So teach me Sensai. Lol

 

[a91what]

Thanks. Car reads between 14.7 and 14.9 at idle when warm. Trying to learn much as possibly. I basically turn all the wrenches on my car and only have a mediocre knowledge on tuning. So teach me Sensai. Lol

Great! That means the datalog was correct. Let me whip up a new revision 1.3 and tomorrow you can do a datalog from cold-start all the way up to full warm.

 

[a91what]

@twohawks777@cox here is the revised tune to get the datalog with. please also provide feedback.

The major changes in this tune revision include.
significantly lowering the warmup enrichment curve and altering the acceleration enrichment pw settings.

 

[5.0Thunder]

Sorry i'm so late in reply to this issue. As y'all may have concluded now, there is an output range that you can set within the autometer wideband. you use the Mode and Select buttons to set the High number at 18, and the Low number at 10. This makes your wideband output 18AFR at 4v and 10AFR at 0v. You go in to tunerstudio and enter those numbers in the "Calibrate AFR" Dialog under the "Custom Linear" option. After this procedure, your Autometer Wideband display should perfectly match the Tunerstudio AFR Gauge Display. If it doesn't (within 0.1 AFR), you may need to check something.

Back to the tune, as I stated before (post #954), it appeared (back then) that the car was pig rich at cold start and that it needed less enrichment. The TPS was also not calibrated properly at the time.

It looks like y'all have figured this out by now so I'll take a look at any new datalog posted and see if anything else jumps out at me.

 

[twohawks777@cox]

@twohawks777@cox here is the revised tune to get the datalog with. please also provide feedback.

The major changes in this tune revision include.
significantly lowering the warmup enrichment curve and altering the acceleration enrichment pw settings.

Upon cold start, accelerator can not be released or car will die until it warms up. Car serges thereafter for several minutes until it reaches about 120*-140*. Car apears to be running alot less rich. If I take the car to 3000 RPM it backfires.When car reaches about 180* the RPM's are slightly 900-1000, but runs steady. Oscillates less than before. Car runs smother than previous tune.

 

[5.0Thunder]

I wish I had megalogviewer at work lol. I'll say one thing about my experience with these cars.. I don't typically find a steady idle above 14AFR. Usually 13.5 is the standard sweet spot with batch fired injection. When moving to sequential, 14.7 is a breeze, with lower idle and a more crackly exhaust note. This is one the reasons I'm switching to MS3 (also want the extra I/O).

 

[a91what]

I prefer the choppy idle, i can get a steady idle around 925 with a choppy cam 14ish AFR and reasonable timing in the 18-22 range. I have found setup this way you will get a idle that oscillates slightly +- 50 rpm around the set point. The sound is amazing done this way, the leaner idle makes the exhaust note a deep thump. However not everyone wants that sound, even a stock cam tuned this way will sound choppy. For a rock steady idle AFR in the mid 13 range and 16-20* idle timing, results vary by cam.

 

[a91what]

OK There has to be something wrong with either the WB calibration or the wiring to the ECU.
its impossible to have a 14.7 AFR that barely moves at all when enrichments are being added to it. The AFR never moves even when 10% fuel is added from EGO correction or the AE is added, when the injector PW doubles there has to be some kind of a AFR change.

This must be resolved or I cannot help further. I don't see anything odd on this end.....

 

[5.0Thunder]

@twohawks777@cox Can you send us a pic of the wideband wiring?

 

[twohawks777@cox]

@twohawks777@cox Can you send us a pic of the wideband wiring?

Yes I will.

 

[twohawks777@cox]

I took everything apart and plugged the male pins directly into the ECU port. Ran car for about 15 min. The gauge is no longer static. Please see if that made a difference. The pins from the WB may not be making a good connection to the ECU female connection. Trying to cover everything on my end. Had to extend wire. The blue wire has the blue heat shrink on it. The third photo of the male connector the blue wire pin is to the left and blk to the right in housing. Thanks

 

[twohawks777@cox]

Please try this data log also. Dissembled everything and did a complete function check on the WB meter itself. It checked out good. Played with some of the modes settings also. Thanks

 

[a91what]

Please try this data log also. Dissembled everything and did a complete function check on the WB meter itself. It checked out good. Played with some of the modes settings also. Thanks

Cool. What tune file goes with this?

 

[twohawks777@cox]

Cool. What tune file goes with this?

 

[twohawks777@cox]

Stand by. let me make sure.

 

[twohawks777@cox]

Think this is it. Its the most current.

 

[a91what]

OK that looked much more normal, try this tune and get another log.

 

[Noobz347]

Question: How useful would it be to have a Tuning Forum on Stangnet?


I've considered it before (and I think there was one once) but we never had enough folks who could speak the language or explain it to folks who didn't.

Consider it and let me know. I'm thinking of locating it above the car forums as it's becoming a more common thing to do. I would have to consider how to keep hand-held garbage out of it. It's all about the forum title.


Digital Self - Tuning Forum


...or something along those line.