Steve's Megasquirt/tunerstudio Help Thread

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Your methodology for tracing down the root cause of the surge is similar to what I would have done. If you shut off all the "helpers" and make idle a purely mechanical thing (turn off the IAC all together so it's just the idle screw, timing advance, and AFR controlling idle speed/stability) and it still does it then there is no point in trying to "fix" it with closed loop idle enabled. In this scenario you hope you can find an AFR, idle speed, and advance that stabilizes idle (at least mostly, sometimes it won't stabilize completely) without any help from the IAC. Sometimes you have to go out of the "norms" with AFR and advance because some engines are just weird and like values that don't follow previous experience. Once you get it idle steady without the IAC involved, you can go back to closed loop idle and dial that in.

I see.. So what you're saying is, I should try unplugging the IAC and try to tune a smoth idle? Or just switch it to open loop? or BOTH?
 
Unplug the iac and use just the throttle stop screw get the idle as low as you can without it oscillating then start adjusting the timing and air fuel ratio. What you're looking to do is set the timing between 15 and 20 and get the air fuel ratio to a point that the car likes. For instance my e303 cam likes the idle at around 16 air fuel ratio this is because overlap makes the wideband read leaner then it actually is. Then start backing the idle down with the screw rinse repeat. Remember more timing will raise the idle less timing will back the idle down
 
I've got issues already. Do I have to be plugged into a MS computer to adjust the gauges/ dash board ?

I've got a registered version of tunerstudio and can't figure this thing out to save my life.

As soon as I can access stangnet from my laptop I'll start pulling files from here. Having issues with that too.

Steep learning curve....yeah I know all about it. [emoji19]
 
I feel like a real idiot...but thanks. What would we do without you man ?

uploadfromtaptalk1474598789598.jpg
 
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Is there a certain way I have to open the file you sent me ?

I saved it in the tunerstudio folder but it keeps asking me if I want to use an existing project or a temporary file to open it with. Is there another way to save it ?
 
Have you created a project for your car yet? Or I should ask do you have the MS yet?

It's asking how you want to view the file, you can view it as temporary which will delete any changes when your done.. (unless you "save as") or to upload the file onto an existing project, (usually "my car" is the default)....

The first time you connect to your MS (firmware upload withholding) it will ask you to create a project. You can create one without using the firmware detect option you must choose one from the drop menu I would suggest 3.4.2
 
Have you created a project for your car yet? Or I should ask do you have the MS yet?

It's asking how you want to view the file, you can view it as temporary which will delete any changes when your done.. (unless you "save as") or to upload the file onto an existing project, (usually "my car" is the default)....

The first time you connect to your MS (firmware upload withholding) it will ask you to create a project. You can create one without using the firmware detect option you must choose one from the drop menu I would suggest 3.4.2
I don't have MS yet but it will be here in the next few weeks.

Thanks for the info. I've been researching for a long time. The settings are different from the ones in your video so I didn't know if I was actually viewing the file or the " preset " project.

Do you have a file I could print of the formulas for corrections ? Saw something in here but have no idea what page it was on.
 
I don't have MS yet but it will be here in the next few weeks.

Thanks for the info. I've been researching for a long time. The settings are different from the ones in your video so I didn't know if I was actually viewing the file or the " preset " project.

Do you have a file I could print of the formulas for corrections ? Saw something in here but have no idea what page it was on.
Which Corrections are you talking about the manual tuning Corrections that I posted if that's the case then it's all just a matter of percentages no matter what the change in value will be linear.

Want 11.5 | have 13 afr. | Ve block =100
Have/want= value
Value* Ve block = new value
New value= dead nuts correct
 
Which Corrections are you talking about the manual tuning Corrections that I posted if that's the case then it's all just a matter of percentages no matter what the change in value will be linear.

Want 11.5 | have 13 afr. | Ve block =100
Have/want= value
Value* Ve block = new value
New value= dead nuts correct
Great ! That's what I needed. [emoji106]
 
From what i see there is nothing wrong with your tune/Ign settings. You can turn on the noise filter for the crank input although I'm not sure it will help.... Are you using a stock balancer? some aftermarket ones have more than one set of marks.
Yes, but we verified that the timing is correct. I'm stumped.

I tried taking the tune from my 302 and changed the parameters to suit the 351 and couldn't get it to even fire. So I put this tune back in and got it to idle finally. I messed with a couple more things and now it wont idle. I don't know what to do.
 
When do you get home tomorrow?? I'm off work all day. If you can find the time and have wifi i can work the computer whilst you make any mechanical changes...

dumb question, new balancer right? any chance the ring has slipped? did we check using the piston stop method?
 
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When do you get home tomorrow?? I'm off work all day. If you can find the time and have wifi i can work the computer whilst you make any mechanical changes...

dumb question, new balancer right? any chance the ring has slipped? did we check using the piston stop method?
I don't know when I will have time to mess with it again, unfortunately. But yes, it's a new balancer. I just can't figure out why it runs great with the fixed timing and not at all off the table.
 
I don't know when I will have time to mess with it again, unfortunately. But yes, it's a new balancer. I just can't figure out why it runs great with the fixed timing and not at all off the table.
It is strange.. please verify that the firing order is correct from the cam card. It may not be a bad idea to shoot DIY an email outlining the issue.

maybe @Stinger has seen this before, can you think of any other scenarios we may have missed??
 
@hoopty5.0 So I understand fully, it has spark even when it doesn't run correct?

It almost certainly has to be some sort of mechanical issue or methodology that's causing the problem. 20 degrees fixed should run identical to 20 degrees from the table.
 
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@hoopty5.0 To help with diagnosis, is this a stock distributor or aftermarket? Does it run if you populate the timing table with the same value as your fix timing value? For example, if your fixed timing is 20 degrees, set your advance table to 20 degrees and see if it runs. This is to determine if it's the "use table" that makes it not run, or if it's the timing value that's causing the issue. Also, to verify rotor phasing, set it to fixed 20 degrees timing and then the rotate the engine over so it's at 20 degrees and then pull the distributor cap and see if rotor is in same vicinity as #1 on the cap.

I've only seen a similar problem one time and it was related to an aftermarket distributor that had "funky" non-stock rotor phasing, hence the questions/tests above.

This is all assuming your timing marks are correct. I've certainly seen plenty of times the wrong marks are used and it causes all sorts of issues.
 
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@hoopty5.0 To help with diagnosis, is this a stock distributor or aftermarket? Does it run if you populate the timing table with the same value as your fix timing value? For example, if your fixed timing is 20 degrees, set your advance table to 20 degrees and see if it runs. This is to determine if it's the "use table" that makes it not run, or if it's the timing value that's causing the issue. Also, to verify rotor phasing, set it to fixed 20 degrees timing and then the rotate the engine over so it's at 20 degrees and then pull the distributor cap and see if rotor is in same vicinity as #1 on the cap.

I've only seen a similar problem one time and it was related to an aftermarket distributor that had "funky" non-stock rotor phasing, hence the questions/tests above.

This is all assuming your timing marks are correct. I've certainly seen plenty of times the wrong marks are used and it causes all sorts of issues.
Sorry, just saw this. Not sure why the tag didn't notify me...
Anyway, it's a stock replacement distributor. I will try to populate the table with 10 degrees and see what happens. It will be Saturday before I can look at it. Will post up when I mess with it. Thanks!