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Megasquirt Experts Wanted!
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joewest  



Joined: 06 Oct 2005
Posts: 234
Location: Portland, OR

PostPosted: Wed Mar 31, 2021 12:28 am    Post subject: Megasquirt Experts Wanted! Reply with quote

Hi All,

I am having a problem with the first start up of my megasquirt conversion. I have been engaged on the MS forums but seem to be stalled ( ) there as well. Having read many of the MS build threads on here for years, I am hoping some of that experience can help me get running! I suspect under-fuelling or EDIS issues I am troubleshooting those (again) at the moment.

Current Tune:

https://app.box.com/s/j3mjw5r8bwbxs2x0jx523lkd9l63r0s4

Datalog:

https://app.box.com/s/fsnjkuutxg9bgat2k1yjzqzeg1g865c0

Build Photos:

https://photos.app.goo.gl/Mua2zeV8zLs5DUgE9

Configuration:

Megasquirt MS2/v3.0 board - modified for EDIS and stepper motor IAV, VR pots calibrated to 2.5V
1979 2.0L motor with JE pistons bored one size over
Added Eaton M62 (clutch pulley driven on an RPM window switch)
Added Innovate LC-1 WBo2 sensor
Added FMIC, Tial BOV
Added Redline throttle body w/Bosch TPS
Ford EDIS, 36-1 trigger wheel, new Motorcraft coil pack, known good ignitor
Siemens 630CC injectors @ 43.7PSI
Fuel pressure set to 43.7PSI on a variable pressure regulator w/91 octane fuel
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'79 924 Supercharged / Track Prepared
'80 931 Daily Driver - Sold
"The number of posts in my profile may represent the number of times I have screwed something up...and admitted it here."


Last edited by joewest on Wed Apr 14, 2021 7:28 am; edited 3 times in total
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924RACR  



Joined: 29 Jul 2001
Posts: 8794
Location: Royal Oak, MI, USA

PostPosted: Wed Mar 31, 2021 4:13 am    Post subject: Reply with quote

1 bar fuel pressure?? For EFI?

Mine's at 45psi... I'd expect somewhere 35+ for EFI... but I'm no expert...

(can't look at the data directly yet)
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Vaughan Scott
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'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype
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Fasteddie313  



Joined: 29 Sep 2013
Posts: 2596
Location: MI

PostPosted: Wed Mar 31, 2021 4:25 am    Post subject: Reply with quote

Yeah fuel pressure..
I was thinking more like 60psi, but I’m no expert either..
What does the documentation of your injectors recommend for normal and max operating pressures?
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joewest  



Joined: 06 Oct 2005
Posts: 234
Location: Portland, OR

PostPosted: Wed Mar 31, 2021 5:55 am    Post subject: Reply with quote

My bad. That's a typ-o. I am at 43.5 PSI which is called out on the specs for the fuel injectors. The fuel pressure regulator is very easy to adjust so maybe I will incrementally increase pressure up to 65 PSI and see what happens. The limits on the injectors is 87 PSI.
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joewest  



Joined: 06 Oct 2005
Posts: 234
Location: Portland, OR

PostPosted: Wed Mar 31, 2021 12:23 pm    Post subject: Reply with quote

No change with fuel pressures between 45 and 80 PSI. Set to 60 and looking at ignition again...
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924RACR  



Joined: 29 Jul 2001
Posts: 8794
Location: Royal Oak, MI, USA

PostPosted: Wed Mar 31, 2021 8:34 pm    Post subject: Reply with quote

OK no, yeah, 43.5 should be well within the happy range.

I have no documentation for my injectors - they're stock 991 Turbo injectors IIRC, so whatever that runs!

I'll take a look at your tables and data when I can, but in the meantime, can you describe what problem you're having, exactly??
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Vaughan Scott
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'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
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924RACR  



Joined: 29 Jul 2001
Posts: 8794
Location: Royal Oak, MI, USA

PostPosted: Wed Mar 31, 2021 9:11 pm    Post subject: Reply with quote

Initial observations from your tune.

You have zero cranking advance. Won't make it easy to start. I use 24 degrees! Starts great.

After-start enrichment is very non-linear, not a smooth curve - would work on cleaning up that shape (secondary priority). It also never goes away to 0 at high temp? You shouldn't need any once the engine's warm - I have mine at 0 by 170F.

Most importantly - base ignition table. I'm expecting your target idle speed is maybe 900rpm? So I don't use any aux idle control valve - just the stock AAV from the original CIS. One less thing to get wrong.

My idle target speed is 1000rpm (could drop it lower, not a high priority). My idle ignition timing is similar to yours, with high vacuum, between 6 and maybe 12-14 degrees. But I have an additional column for ignition advance below, at 600 rpm, where the advance jumps to 27 degrees; this allows the engine to recover quickly when the speed drops below 1000rpm.

I'd suggest taking that entire first column (you have at 701), maybe drop the speed (X value) to 600 or so, maybe even 500, and put all values under 100kPa to 27. It should help a lot to maintaining an idle, regardless of stepper motor control (which will of course be far slower).

Looking a bit further out - you'll want to collapse your ignition (and of course fuel) table substantially in the Y axis; you have a big stack of points in the vacuum range, which is find until that blower kicks in! You'll need to add room for one or two rows in positive boost.

For comparison, my Y points are:
220
180
150
120
110
100
95
90
85
80
45
30

Don't really spend a lot of time below 80, unless idling/throttle closed, so not a lot of need for tuning resolution down there.

You may also wish to disable EGO control until you get the tune roughed in a lot better, FYI...

Hope that helps...
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Vaughan Scott
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'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype
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joewest  



Joined: 06 Oct 2005
Posts: 234
Location: Portland, OR

PostPosted: Thu Apr 01, 2021 1:30 am    Post subject: Reply with quote

Awesome! Cannot wait to try these tonight...
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joewest  



Joined: 06 Oct 2005
Posts: 234
Location: Portland, OR

PostPosted: Fri Apr 02, 2021 2:40 am    Post subject: Reply with quote

No change.

I am going to keep these settings in the tune and try a bit of starter fluid to see what kind of results I get.
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924RACR  



Joined: 29 Jul 2001
Posts: 8794
Location: Royal Oak, MI, USA

PostPosted: Fri Apr 02, 2021 4:07 am    Post subject: Reply with quote

You have failed to describe the actual problem you are having.

So it's kinda hard to provide targeted advice.
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Vaughan Scott
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'79 924 #77 SCCA H Prod racecar
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#25 Hidari Firefly P2 sports prototype
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joewest  



Joined: 06 Oct 2005
Posts: 234
Location: Portland, OR

PostPosted: Fri Apr 02, 2021 5:47 am    Post subject: Reply with quote

Sorry.

The car will not make its first start after changing over to the MS system and adding the other upgrades described above. I followed the MS hardware and setup guides per the manuals and have stopped at "now start the car".

I have confirmed a solid RPM Sync and have calibrated all of the sensor inputs, but it just cranks and will not fire. After sitting for a while, I crank it again and a few cylinders fire but then nothing. I suspect it is just burning off what has accumulated in the cylinders.

I verified mechanical timing as well but nothing...
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"The number of posts in my profile may represent the number of times I have screwed something up...and admitted it here."
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924RACR  



Joined: 29 Jul 2001
Posts: 8794
Location: Royal Oak, MI, USA

PostPosted: Fri Apr 02, 2021 8:03 am    Post subject: Reply with quote

Hmmm, not a whole lot to see in that log file, looks like only a trigger log? Can you share a normal full log of it trying to start?

If it does spark a couple of times, that might seem to indicate that it is indeed running ignition/giving spark, making one think it might be fueling related... a full log might give some more clues.

Mine pretty much kicked IMMEDIATELY when I tried to run it the first time, once I got a working crank sensor (0 mileage failure on new sensor, so unrelated).

My injectors are 627cc/min, virtually the same as yours, with almost the same fuel pressure - I would expect that the fueling curve might be expected to be similar if not identical? If so, your fuel table looks to be approximately double mine, mine idles at around 20, only going up to about 50 at 100kPa at around 1000rpm. Could you be pig-rich?

Timing-wise, other than the lack of advance on cranking, you should have some degree of function at the values you have, if not ideal performance. You did give it a healthy shot of cranking advance, right?
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Vaughan Scott
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'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype
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924RACR  



Joined: 29 Jul 2001
Posts: 8794
Location: Royal Oak, MI, USA

PostPosted: Fri Apr 02, 2021 8:10 am    Post subject: Reply with quote

My fuel map:


My ignition map:

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Vaughan Scott
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'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype
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joewest  



Joined: 06 Oct 2005
Posts: 234
Location: Portland, OR

PostPosted: Fri Apr 02, 2021 8:12 am    Post subject: Reply with quote

Holy crap. I am way off....

I will drop these values in tonight an tune a bit more.

Thanks!!
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"The number of posts in my profile may represent the number of times I have screwed something up...and admitted it here."
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924RACR  



Joined: 29 Jul 2001
Posts: 8794
Location: Royal Oak, MI, USA

PostPosted: Sat Apr 03, 2021 8:21 pm    Post subject: Well?!? Reply with quote

Don't leave me hanging here! What's the word???
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'79 924 #77 SCCA H Prod racecar
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#25 Hidari Firefly P2 sports prototype
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