the higher the throttle the leaner??
08-16-2015, 08:04 PM
#1
Super Member
Thread Starter
the higher the throttle the leaner??
Don't known whats going on, sometimes if I give half throttle, my afr gauge goes lean and just bogs and stutters and sometimes its fine, it's definitely lost power though, not as fast as it was, no cel though. Not sure if it's meth related, because I currently have it capped so it's not spraying
08-17-2015, 07:12 AM
#3
Do you have a tune? I'm also betting you have a larger TB. Sounds like the dreaded hiccup associated with larger TBs.
It's very minor if you are running a clutched pulley. Sometimes the only way you even realize you have triggered it is when what you described happens.
If you have a stock TB, check for a disconnected vacuum hose
It's very minor if you are running a clutched pulley. Sometimes the only way you even realize you have triggered it is when what you described happens.
If you have a stock TB, check for a disconnected vacuum hose
08-17-2015, 09:12 AM
#6
Yep, just disconnected vacuum hoses. Rerouted them and its been much better. Also most of my problem stemmed from my fixed pulley, Tony's tune just about fixed that too.
I am back with a clutched pulley, but I haven't gotten any issues with hiccuping
I am back with a clutched pulley, but I haven't gotten any issues with hiccuping
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08-17-2015, 03:48 PM
#8
I have done several datalogs when I had this issue, all I saw was a sudden lean out. Nothing to report there
08-17-2015, 04:07 PM
#10
Its been a while since my last incident. I will see if I can find something later tonight
08-17-2015, 04:14 PM
#11
I think the car hiccups because it runs too lean at higher part throttle loads. I believe this is something easily tuned out by tuners if they paid attention to the 25-50% throttle @~1800rpm and up. The larger TB allows for more air and the car has to go out of its normal compensation parameters to reach stoich and eventually goes into limp mode. A restart clears all that out for now.
If your vacuum hoses are not closed off somehow, it happens more often. The MB larger TBs seal off all the vacuum hoses hence the reason it does not happen as often. Aftermarket ones do leave the crankcases vented to the air, somehow hiccups happens more in those cases. But it could also simply be that the 82mm flows a lot more air than the MB 80mm (which is actually 78mm)
My logs showed 14.7-15.1 AFR fluctuations around the times when hiccups happened. Different from the 14.5-14.8 AFR fluctuations every other time
If your vacuum hoses are not closed off somehow, it happens more often. The MB larger TBs seal off all the vacuum hoses hence the reason it does not happen as often. Aftermarket ones do leave the crankcases vented to the air, somehow hiccups happens more in those cases. But it could also simply be that the 82mm flows a lot more air than the MB 80mm (which is actually 78mm)
My logs showed 14.7-15.1 AFR fluctuations around the times when hiccups happened. Different from the 14.5-14.8 AFR fluctuations every other time
Last edited by kponti; 08-17-2015 at 04:16 PM.
08-18-2015, 08:24 AM
#13
I still got an occasional hiccup, however the car recovered in less than a second and I never had to restart or have any drivability issues.
When the maps ran a little richer (at part throttle), I did not get hiccups.
08-18-2015, 11:54 AM
#14
You should be fine. Tony got mine sorted out even with my 82mm aftermarket TB and FSP.
I still got an occasional hiccup, however the car recovered in less than a second and I never had to restart or have any drivability issues.
When the maps ran a little richer (at part throttle), I did not get hiccups.
I still got an occasional hiccup, however the car recovered in less than a second and I never had to restart or have any drivability issues.
When the maps ran a little richer (at part throttle), I did not get hiccups.
08-18-2015, 01:27 PM
#15
Datalog for Jerry and describe what is happening. He should be able to tune around it
