Tune analyze live - help with idle?

For discussing Phil Tobin's TunerStudio MS is the MegaSquirt edition of TunerStudio, a next generation tuning application. It provides the ability to configure and tune all MegaSquirt controllers and is 100% compatible with MegaTune ini files and msq's.

Moderator: LT401Vette

Post Reply
ironwill11
Helpful Squirter
Posts: 48
Joined: Sun Feb 22, 2015 5:14 pm

Tune analyze live - help with idle?

Post by ironwill11 »

Hello,

I am trying to get my 4.3 TBI idling properly.

Question : Will Tune analyze live help with tuning the idle if it idles steady just too high?

Background:
4.3 TBI with MSII version 3.0
TunerstudioMS 3.0
GM HEI 8 pin module
DIYAutoTune 10' wire harness
IAC - GM IAC, 4 wire (square plug)
Engine starts reliably and idle starts at 1500 rpm and increases to 1900 rpm as the coolant temp goes up.
IAC is wired properly according to the diagram and markings on wires in harness (have verified correct wiring about 87 times now and pulled the IAC and watch it fully retract when key is turned to run). The only issue I see is that it fully retracts when the key is turned on and then goes back to its normal position without turning the key off.
I have read through all relating manuals several times, and researched other articles on the subject. Ready to go bald and pull out my hair. :shock:

Would appreciate any info I can get

Will
Matt Cramer
Super Squirter
Posts: 2951
Joined: Sat Jul 03, 2004 11:35 am

Re: Tune analyze live - help with idle?

Post by Matt Cramer »

Tune Analyze Live will tune it for a specific AFR, but it won't tell you what specific AFR you ought to be running. So it won't be helpful here. We have some idle tuning tips here:

https://www.DIYAutoTune.com/support/tec ... egasquirt/
ironwill11
Helpful Squirter
Posts: 48
Joined: Sun Feb 22, 2015 5:14 pm

Re: Tune analyze live - help with idle?

Post by ironwill11 »

Thank you for your reply.

I have read that document backward, forward, and side to side. Even my wife has read that document.

I still have idle frustrations.

Idle starts at 1300 rpms and warms up to 1900 rpms. It seems as if my IAC was going backward. I had it wired backward and then switched the polarity on 1 of the coils so every wire on the harness goes to the pin in the diagram found in the "Idle Control with your MegaSquirt-II™ controller". I have taken the IAC out and turned the key to on. The pintle retracts all the way but then goes back to where it started. However, when I start the engine it still seems to run backward. Idle goes up as it warms up.

Will
kjones6039
Master Squirter
Posts: 618
Joined: Sat Jul 22, 2006 7:02 pm
Location: Eureka, Nevada USA
Contact:

Re: Tune analyze live - help with idle?

Post by kjones6039 »

It would be helpful if you could post a log and an msq. It sounds like your idle control just needs a little work.

Ken
1979 Corvette - 383 CID SBC w/ Holley Pro-Jection 900 CFM TBI, 4-85 lb lo-z injectors & Walbro 255 pump
MS2 v3 w/ms2extra 3.4.0 Release
36-1, Delphi LS2/7 coils in wasted spark, driven by v2.0 logic board from JBPerformance
Spartan Lambda Sensor from 14point7
ironwill11
Helpful Squirter
Posts: 48
Joined: Sun Feb 22, 2015 5:14 pm

Re: Tune analyze live - help with idle?

Post by ironwill11 »

It would be helpful if you could post a log and an msq. It sounds like your idle control just needs a little work.

Ken
Attached in my log and msq.

Murphy showed up and brought his law with him (no love in NJ). I started it tonight and the idle did not climb but it did not go below 1100rpm either.

Background:
4.3l TBI (injectors 5235209)
MSII V3.0 DIYAutoTune 10' harness
Active flyback and regular flyback circuit as suggested in the manual
I have tried running it at 3 squirts per cycle but the engine would start and then die a second later. After increasing the afterstart enrichment up to 60% (well outside the range suggested in the manual) it would run for 3 seconds then die. 6 squirts per cycle is the only thing I can get it to run on.
2016-07-13_21.00.27_IDLE INCREASE.msl
2016-07-13_20.04.08.msq
Any advice or adjustments would be greatly appreciated

Will
You do not have the required permissions to view the files attached to this post.
trakkies
Super Squirter
Posts: 1162
Joined: Tue Dec 30, 2008 3:06 am
Location: SW London, UK

Re: Tune analyze live - help with idle?

Post by trakkies »

If you get a change at idle with a different number of squirts per cycle, sounds like your injector dead time isn't correct?

I've never found VEAL of any real use at idle.

One trick is to start with all the VE table cells around the idle one at the same value.
Dave P, London UK.
Rover V-8
MSII V3
EDIS
Tech Edge Wideband
ironwill11
Helpful Squirter
Posts: 48
Joined: Sun Feb 22, 2015 5:14 pm

Re: Tune analyze live - help with idle?

Post by ironwill11 »

Will look into that Dave. Thanks.

Anyone else have any suggestions? [see msq & datalog above]

Thanks everyone!
trakkies
Super Squirter
Posts: 1162
Joined: Tue Dec 30, 2008 3:06 am
Location: SW London, UK

Re: Tune analyze live - help with idle?

Post by trakkies »

ironwill11 wrote:Will look into that Dave. Thanks.

Anyone else have any suggestions? [see msq & datalog above]

Thanks everyone!
Your log shows lots of TPS noise?
Dave P, London UK.
Rover V-8
MSII V3
EDIS
Tech Edge Wideband
ironwill11
Helpful Squirter
Posts: 48
Joined: Sun Feb 22, 2015 5:14 pm

Re: Tune analyze live - help with idle?

Post by ironwill11 »

Thanks Dave. I will check this out.

Will
ironwill11
Helpful Squirter
Posts: 48
Joined: Sun Feb 22, 2015 5:14 pm

Re: Tune analyze live - help with idle?

Post by ironwill11 »

Hey Dave,

I noticed the TPS noise as well. On the graph it looks like a lot however, it only fluctuates between 3-5%.

Will
Post Reply