MS3 Basic 6000 rpm backfire and check engine light
#1
MS3 Basic 6000 rpm backfire and check engine light
Gents,
I made some changes to my 1999 that warranted a new tune. Everything was going fantastic. I have not had any problems like this in the past. We were nearly done with the WOT tuning when it backfired at 6000 rpm and threw a Code 64 indicating a loss of sync. The Check Engine light came on. It happens at 6000 rpm regardless of throttle position. Otherwise, the car runs great. Starts and runs just fine below 6000, and even runs fine after the backfire. The Check Engine light does not come on if the engine is turned off then restarted, unless I crack 6000 rpm again.
I replaced the crank position sensor, but no change. Any ideas?
Thanks much,
poormxdad
I made some changes to my 1999 that warranted a new tune. Everything was going fantastic. I have not had any problems like this in the past. We were nearly done with the WOT tuning when it backfired at 6000 rpm and threw a Code 64 indicating a loss of sync. The Check Engine light came on. It happens at 6000 rpm regardless of throttle position. Otherwise, the car runs great. Starts and runs just fine below 6000, and even runs fine after the backfire. The Check Engine light does not come on if the engine is turned off then restarted, unless I crack 6000 rpm again.
I replaced the crank position sensor, but no change. Any ideas?
Thanks much,
poormxdad
#2
SADFab Destructive Testing Engineer
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How far out is the crank sensor placed?
This sounds exactly like the issue that we had on Eds car when I forgot to adjust the VR conditioning pots correctly. But from what I remember @Reverant uses a different circuit for the crank input.
He will be able to answer better.
This sounds exactly like the issue that we had on Eds car when I forgot to adjust the VR conditioning pots correctly. But from what I remember @Reverant uses a different circuit for the crank input.
He will be able to answer better.
#5
My Friend, I have no idea what "VR conditioner pots" are.
I changed the pre-Rotrex intake piping by deleting the gutted MAF and adding a sealed cold air shroud. The restriction had been bad enough to require a retune. I gained nearly two pounds of boost, so there were extensive changes to the tune but everything seemed fine. When the backfire and loss of sync happened the second time, the tuner reloaded the previous tune. No change, so maybe it's NOT a setting.
This blows. I'm over my head and supposed to be on track Monday.
poormxdad
I changed the pre-Rotrex intake piping by deleting the gutted MAF and adding a sealed cold air shroud. The restriction had been bad enough to require a retune. I gained nearly two pounds of boost, so there were extensive changes to the tune but everything seemed fine. When the backfire and loss of sync happened the second time, the tuner reloaded the previous tune. No change, so maybe it's NOT a setting.
This blows. I'm over my head and supposed to be on track Monday.
poormxdad
#7
My Friend, I have no idea what "VR conditioner pots" are.
I changed the pre-Rotrex intake piping by deleting the gutted MAF and adding a sealed cold air shroud. The restriction had been bad enough to require a retune. I gained nearly two pounds of boost, so there were extensive changes to the tune but everything seemed fine. When the backfire and loss of sync happened the second time, the tuner reloaded the previous tune. No change, so maybe it's NOT a setting.
This blows. I'm over my head and supposed to be on track Monday.
poormxdad
I changed the pre-Rotrex intake piping by deleting the gutted MAF and adding a sealed cold air shroud. The restriction had been bad enough to require a retune. I gained nearly two pounds of boost, so there were extensive changes to the tune but everything seemed fine. When the backfire and loss of sync happened the second time, the tuner reloaded the previous tune. No change, so maybe it's NOT a setting.
This blows. I'm over my head and supposed to be on track Monday.
poormxdad
#18
A few things.
First, I can't find an option for Composite log. I thought it would be in Tools.
Second. When I was at VIR a couple of weeks ago, I ran over the gator coming out of the Oak Tree turn. It shook the crap outta the car and I got a check engine light. No drivability issues though. I came into the grid, turned the car off and back on and all was well. No apparent issues till on the dyno a couple of days ago. I'm checking connections now.
I've got Shadow Dash installed on my cell phone. I hooked it up on the way home from work a little while ago and although it went through all the right notifications--it told me it was connected, loading the file and was going online, it never actually went online. Symptom?
Thanks for everyone's help so far. Beers on me if the opportunity arises.
poormxdad
First, I can't find an option for Composite log. I thought it would be in Tools.
Second. When I was at VIR a couple of weeks ago, I ran over the gator coming out of the Oak Tree turn. It shook the crap outta the car and I got a check engine light. No drivability issues though. I came into the grid, turned the car off and back on and all was well. No apparent issues till on the dyno a couple of days ago. I'm checking connections now.
I've got Shadow Dash installed on my cell phone. I hooked it up on the way home from work a little while ago and although it went through all the right notifications--it told me it was connected, loading the file and was going online, it never actually went online. Symptom?
Thanks for everyone's help so far. Beers on me if the opportunity arises.
poormxdad