microsquirt lsx sputter/ misfire
06-20-2016, 12:49 PM
#1
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microsquirt lsx sputter/ misfire My current setup is an lr4, s475, ls2 coils, microsquirt. When im cruising down the road the car has a minor sputter heard through exhaust and can be felt in the vehicle. My tuner said the car appears to be misfiring because he said the map was choppy when he looked at my datalog.
I tried to ohm the coils and the readings are all equal to one another, but not the right specs according to gm specs. Plugs have a little bit of carbon buildup on them because we're in the middle of tuning it and its rich still.
I adjusted dwell to 4.5ms as per msxtra. Still the same. Going to try to change the plugs tonight. Currently has br7ef's.. Is that what I should get again or should I go with the tr6 plugs?
I can post a datalog if thatd help.
-Cody
I tried to ohm the coils and the readings are all equal to one another, but not the right specs according to gm specs. Plugs have a little bit of carbon buildup on them because we're in the middle of tuning it and its rich still.
I adjusted dwell to 4.5ms as per msxtra. Still the same. Going to try to change the plugs tonight. Currently has br7ef's.. Is that what I should get again or should I go with the tr6 plugs?
I can post a datalog if thatd help.
-Cody
06-20-2016, 04:13 PM
#2
Its choppy cause its misfiring. Plz make sure you have good fuel pressure, spark plug wires are not touching headers and post the tune and a log file. Then I can help. If you are running an internet tune, you need to tweak (lower) the VE table to get it so its not too rich. If you are using a wideband ensure you don't have an exhaust leak letting outside air get sucked in between exhaust pulses. PM me if necessary.
06-20-2016, 04:54 PM
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Its choppy cause its misfiring. Plz make sure you have good fuel pressure, spark plug wires are not touching headers and post the tune and a log file. Then I can help. If you are running an internet tune, you need to tweak (lower) the VE table to get it so its not too rich. If you are using a wideband ensure you don't have an exhaust leak letting outside air get sucked in between exhaust pulses. PM me if necessary.
The plug wires ill have to check on the rubbing factor, but I know the one is like a paper width away from the alternator.
Im using an aem wideband. I don't see any exhaust leaks anywhere but I may be wrong. Everything is v bands and tigged.
this is the most recent datalog below. This is after I changed the dwell time from 2.5 ms to 4.5 ms.
Going to throw a new set of plugs in it tonight and try to get another log with those as well and see if that changes anything.
06-21-2016, 07:37 PM
#6
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did a quick look at your MSQ, only thing that popped out at me is you could try changing your injector dead time to 1.300 maybe 1.200 that might help your idle issue.. I run mine at 1.300 and idles great...
06-22-2016, 07:10 AM
#7
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Did anybody get a chance to look at the logs and see if anything looks off?
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06-22-2016, 07:17 AM
#8
smooth out you VE map and turn off accel enrichment for now. Get the VE dialed in. It shouldnt look like what you have when your done. You may get 1 or 2 small valleys or peaks but nothing like what your seeing there.
Once the VE is dialed in, turn on the accel enrichemnt.
Also, thats a **** ton of timing in boost. Might be good for e85 (i dont have much expeeirnce with it)
I can tell you that i melted a piston on a 5.3 with a s475 running 8 degrees at peak tq and running out to 12 degrees by redline at 16lbs.
You have 16 degress all the way across at 16 lbs.
Once the VE is dialed in, turn on the accel enrichemnt.
Also, thats a **** ton of timing in boost. Might be good for e85 (i dont have much expeeirnce with it)
I can tell you that i melted a piston on a 5.3 with a s475 running 8 degrees at peak tq and running out to 12 degrees by redline at 16lbs.
You have 16 degress all the way across at 16 lbs.
06-22-2016, 08:27 AM
#9
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smooth out you VE map and turn off accel enrichment for now. Get the VE dialed in. It shouldnt look like what you have when your done. You may get 1 or 2 small valleys or peaks but nothing like what your seeing there.
Once the VE is dialed in, turn on the accel enrichemnt.
Also, thats a **** ton of timing in boost. Might be good for e85 (i dont have much expeeirnce with it)
I can tell you that i melted a piston on a 5.3 with a s475 running 8 degrees at peak tq and running out to 12 degrees by redline at 16lbs.
You have 16 degress all the way across at 16 lbs.
Once the VE is dialed in, turn on the accel enrichemnt.
Also, thats a **** ton of timing in boost. Might be good for e85 (i dont have much expeeirnce with it)
I can tell you that i melted a piston on a 5.3 with a s475 running 8 degrees at peak tq and running out to 12 degrees by redline at 16lbs.
You have 16 degress all the way across at 16 lbs.
Goal overall is to run 14psi for now and get used to the car. Ive never run rwds only fwd turbo cars.
Ive had the car built for 2 years and cant find anybody to tune it and im scared to. My friend tunes neons on ms all the time and he was the one helping.
I never got into boost with the car yet. Been up to 0.5psi and that was it as he told me to stay out of boost.
The tune that was used as a base was matts Fairmont tune.
I just want to take the car to the track once this year and id be happy. If somebody can help with some remote tuning and help me get this thing squared away thatd be great.
06-22-2016, 08:46 AM
#12
If idle speed is surging, raise or lower the timing table in that section a few degrees to get it to stabilize. Most internet tunes leave much to be desired as they are functional but need tweaked for your engine. I am kind of tied up with another project or I would jump right in.
Here is how I adjusted the timing on a Microsquirt 302 mustang.
Here is how I adjusted the timing on a Microsquirt 302 mustang.
Last edited by aknovaman; 06-22-2016 at 09:09 AM.
06-22-2016, 10:17 AM
#14
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If idle speed is surging, raise or lower the timing table in that section a few degrees to get it to stabilize. Most internet tunes leave much to be desired as they are functional but need tweaked for your engine. I am kind of tied up with another project or I would jump right in.
Here is how I adjusted the timing on a Microsquirt 302 mustang.
Microsquirt 68 Mustang Garage Tuning Part 4 - YouTube
Here is how I adjusted the timing on a Microsquirt 302 mustang.
Microsquirt 68 Mustang Garage Tuning Part 4 - YouTube
Ill try to raise/ lower the timing table at idle and see if the hunt goes away. i know very minor amounts from the last 3 cars ive owned being on ms, but not enough to attempt my own tuning. I started reading up on tuning and gave up as it made no sense to me lol. Im a hands on learner, not a reader. Lol.
As far as the miss goes, is that because the timing table is way off then?
If anybody does remote tuning, ill gladly pay them for their time.
-Cody
06-22-2016, 10:25 AM
#17
your required fuel isnt setup right, and you need to start there. Also, its always critical that you shoot base timing and make sure its synced (timing light matches what you are commanding in the software)
The VE map you have makes the megasquirt do alot of interpolating, which could be adding to the problem. Big steps in cells makes the MS average between them. Having smooth transitions takes that away.
Other then the timing values being higher then im comfortable with in boost, it looks pretty good.
I made some changes while sitting at work. Literally just best guessing at some things based off what ive done in the past.
Ill upload it a little later.
The VE map you have makes the megasquirt do alot of interpolating, which could be adding to the problem. Big steps in cells makes the MS average between them. Having smooth transitions takes that away.
Other then the timing values being higher then im comfortable with in boost, it looks pretty good.
I made some changes while sitting at work. Literally just best guessing at some things based off what ive done in the past.
Ill upload it a little later.
06-22-2016, 10:36 AM
#18
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your required fuel isnt setup right, and you need to start there. Also, its always critical that you shoot base timing and make sure its synced (timing light matches what you are commanding in the software)
The VE map you have makes the megasquirt do alot of interpolating, which could be adding to the problem. Big steps in cells makes the MS average between them. Having smooth transitions takes that away.
Other then the timing values being higher then im comfortable with in boost, it looks pretty good.
I made some changes while sitting at work. Literally just best guessing at some things based off what ive done in the past.
Ill upload it a little later.
The VE map you have makes the megasquirt do alot of interpolating, which could be adding to the problem. Big steps in cells makes the MS average between them. Having smooth transitions takes that away.
Other then the timing values being higher then im comfortable with in boost, it looks pretty good.
I made some changes while sitting at work. Literally just best guessing at some things based off what ive done in the past.
Ill upload it a little later.