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Old 05-17-2014, 09:51 PM   #1
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Default Help diagnose no start, please

The 2000 NB1 with Reverent-built Megasquirt 2 has failed to start properly for a while. Stock car as far as engine is concerned. It cranks but does not fire at all. The odd thing is that if stock ECU is substituted the cars starts right up. If Megasquirt is plugged in after that the car also starts.

I've taken two plugs out after some serious cranking today. I can smell gas a bit but the plugs are bone dry. Try to run Data logging while starting. The resulting files (one attached) appear to be empty for some reason (why would that be?). The two tunes that I've tried are also attached. The car used to start fine with second of this tunes when it was put in 2 years ago.

Guys, I'm truly at the end of the rope and really frustrated with this. Don't understand MS well enough to figure things out and the fact that the car starts after it's started on stock ECU baffles me. I guess it's not getting fuel with MS, getting it with stock ECU and then starts on what's left over in the lines? I tried to wait for 10-20 seconds between turning the car on and starting - no change. I've replaced Crank Sensor recently - no change. Help! Please, please!
Attached Files
File Type: msl 2014-05-17_19.51.00.msl (719 Bytes, 73 views)
File Type: msq CurrentTune.msq (84.6 KB, 38 views)
File Type: msq final_from_DSG.msq (79.0 KB, 35 views)
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Old 05-17-2014, 11:40 PM   #2
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Further to this - the tach doesn't jump when the car cranks.
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Old 05-18-2014, 03:44 AM   #3
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Kindly remind me who you bought this unit from or the serial number of the ECU.
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Old 05-18-2014, 12:43 PM   #4
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Quote:
Originally Posted by Reverant View Post
Kindly remind me who you bought this unit from or the serial number of the ECU.
Thanks, Reverant, it was built for Jess Dillow two years ago.
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Old 05-18-2014, 01:44 PM   #5
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Looks like its a unit from the September '11 group buy.

If it starts if you have first started it on the stock ECU, then you only need to tune your cranking pulsewidths.
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Old 05-18-2014, 04:07 PM   #6
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I am an idiot. I repeat, I am an idiot.

The car refused to start with stock ECU for the last day or so and was periodically (rarely) shaking at idle before that as well. I've gone through a bunch of things... and, of course, one of the simplest ones was overlooked. Spark plug on cylinder 4 was really corroded around the grounding nut and was probably not firing. Of course, I've checked #1 and #3, they fired, and I was satisfied that the coil pack is probably OK. Never pulled #4 plug. Replaced the plugs and wires with new ones and the car started right up on stock ECU. Which followed by starting OK on MS. Which is back to how it behaved before.

The real test now is whether it'll start on MS after sitting for a day or two. And that's where I'd need to get some help. The MS is, indeed, from '11 group buy and was first installed in May-June '12. Dimitris and others, do you see anything in either of the tunes I've attached, where I can improve starting? And improve off-idle stalling when engine is still cool on "Current" tune)? By "playing with pulsewidths", could you give some detail? Increase or decrease, which ones, exactly?

Again, your help is greatly and truly appreciated! Being an autocross ***** I'd be more than happy to put decals on my car that would point people to your products
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Old 05-20-2014, 10:31 PM   #7
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I'm having the same problem as before - the car starts OK with stock ECU and starts OK after that with MS. But not when initially trying to start with MS.

Could you please see my two tune files and suggest what can be specifically improved for easier start?
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Old 05-21-2014, 11:00 AM   #8
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Are you using CurrentTune or final_from_DSG?
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Old 05-21-2014, 06:22 PM   #9
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I tried both with similar startup issues. Currently using "Current tune". This tune was an attempt to help hard starting and stalling when engine is not warmed up - issues I've encountered with DSG_Final tune.

Thanks in advance for you help!

Last edited by nile13; 05-21-2014 at 07:05 PM.
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