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Old 01-24-2010, 02:58 PM   #1
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Default Cough, splutter, bang, flames when in boost..

Hi all,

I'm a megasquirt noob and have been having no end of problems, one thing gets sorted then it seems something else crops up.

Anywho, i'm supercharged with MS1 and LC-1 and have been trying out the new Autotune.

It seems to be working but sometimes when in boost the car chokes and back fires, so far it seems to only do it when i'm not running autotune??

A friend helped with my AFR target table and I started with the MSDIYPNP map.

Anyone have any ideas?

Thanks in advance...

Mel
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Old 01-24-2010, 02:59 PM   #2
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Post up a datalog of the event along with your .msq. Do you have new plugs/wires? What does your wideband say when it happens?
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Old 01-24-2010, 03:03 PM   #3
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Jeff thanks for the quick response.

Will pop out in the car shortly and try and capture it.

The plugs are about 6 months old, NGK Longreach and the leads about a year old, 8mm MX5parts branded (UK specialist)
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Old 01-24-2010, 03:06 PM   #4
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New plugs atleast.
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Old 01-24-2010, 03:21 PM   #5
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ok just been out for a spin, it did it a couple of times, in 2nd, 3rd and 4th...

Now, how do i upload the files?

thanks

Mel
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Old 01-24-2010, 03:22 PM   #6
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go to reply and under attachments attach and upload the file. What is your AFR in boost saying?
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Old 01-24-2010, 03:29 PM   #7
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Quote:
Originally Posted by SKMetalworks View Post
go to reply and under attachments attach and upload the file. What is your AFR in boost saying?
Cheers, it reads around 12, i tried to look at the gauge when it stutters but the car jerks to much and I crap myself!
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Old 01-24-2010, 03:30 PM   #8
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Whats your overboost protection set at?
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Old 01-24-2010, 03:38 PM   #9
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Here's the tune, cant get the datalog to upload, it keeps saying invalid file?
Attached Files
File Type: msq 2010-01-24_14.30.05.msq (31.8 KB, 81 views)
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Old 01-24-2010, 03:38 PM   #10
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Quote:
Originally Posted by skmetalworks View Post
whats your overboost protection set at?

255
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Old 01-24-2010, 03:46 PM   #11
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What is your plug gap? Are you getting good afr in boost? VE table is a bit thin.
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Old 01-24-2010, 03:57 PM   #12
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heres the log, hope it works..
Attached Files
File Type: xls 2010-01-24_19.10.31.xls (1,000.9 KB, 70 views)
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Old 01-24-2010, 03:59 PM   #13
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Quote:
Originally Posted by Ben View Post
What is your plug gap? Are you getting good afr in boost? VE table is a bit thin.

Not to sure, i dont have the correct socket here to get them out. Or the tool to check.

When you say VE table do you mean the AFR target table?

Mel
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Old 01-24-2010, 04:10 PM   #14
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It might be time to run to the hardware store and pick up some proper tools, mate!

VEtable = fuel table.
Your AFR targets aren't bad.
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Old 01-24-2010, 04:22 PM   #15
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I'll grab some new plugs tomorrow, so they need to be gapped before they are fitted?

Has anyone had a chance to check my log?

cheers
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Old 01-24-2010, 04:25 PM   #16
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Quote:
Originally Posted by fr3n2y View Post
heres the log, hope it works..
I reviewed the log. I see a couple of resets that you would have felt, but there's no obvious cause. Likely to be a little noise coming form somewhere. Your alternator could be getting old (it's not holding >14V), or you might need to clean up your grounding points.

You're also a little lean in boost for my liking.

Quote:
Originally Posted by fr3n2y View Post
I'll grab some new plugs tomorrow, so they need to be gapped before they are fitted?

Has anyone had a chance to check my log?

cheers
Yes you need to gap them with a feeler gauge or gap tool. .030" should be fine.
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Old 01-24-2010, 04:29 PM   #17
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Thanks Ben,

Alternator was replaced around 18 months ago for a new genuine mazda part.

Are the red lines in the log the resets? They correspond with when the car splutters..

How would i richen it up, changing the AFR target table?

cheers
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Old 01-24-2010, 04:38 PM   #18
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As per usual, I am the guy helping him with it. The only thing I have to add here is to explain the lean in boost ve table. So far the table has for the most part been set with autotune in TS. The clutch in the car is completely overwhelmed, and will be replaced this weekend. As a result we can't really get anything over around 4.5k rpm out of it before the clutch lets go. Thats why the high rpm, high boost area of the map is still so lean. It hasn't really been mapped at all. After we do the clutch we will gingerly do a few runs to tune that area in, and then hand smooth things a bit.

And it was me that came up with that AFR target table, glad to hear it gets general approval
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Old 01-24-2010, 04:50 PM   #19
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A 'new' part, or a re-man? Reman parts can have huge variations in quality. It might be fine, but I find it suspicious.

Your targets don't look bad, but the log shows the car running leaner than the targets. Do you have a gauge on the LC1, and if so, does it agree with the dashboard in megatune or tunerstudio?

You could try running the log through megalogviewer and see if ve analyzer doesn't richen it up some. It's generally better to start rich and work towards the target, than to start lean and go rich towards the target.
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Old 01-24-2010, 05:12 PM   #20
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Yeah brand new.

The lc-1 gauge matches tunerstudio.

Will log all the way to work tomorrow and if it changes anything.
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