Intermittent Exhaust Pop
08-12-2013, 01:27 AM
#1
Intermittent Exhaust Pop Nothing on the car has really changed lately.
It's not coming out of the intake as I get no MAP spikes. The car pulls just like before at WOT. I get no popping on heavy accel or decel.
From idle up to about 1800RPM I get an intermittent pop in the exhaust. Once or twice every ten min. It only happens when the exhaust is really hot....slow around town. After I'm on the freeway a while it doesn't happen anymore. Only happens at light throttle. The NB and WB O2's do not show a rich condition. No cats.
I have put in new plugs. TR6's. Checked the valve springs and checked lift for a collapsed lifter. It sounds like it's coming from the passenger side.
I have not checked the plug wires yet but it runs fine at WOT.
Any ideas?
Edit, I have HPTuners and can post the tune or make changes as necessary.
It's not coming out of the intake as I get no MAP spikes. The car pulls just like before at WOT. I get no popping on heavy accel or decel.
From idle up to about 1800RPM I get an intermittent pop in the exhaust. Once or twice every ten min. It only happens when the exhaust is really hot....slow around town. After I'm on the freeway a while it doesn't happen anymore. Only happens at light throttle. The NB and WB O2's do not show a rich condition. No cats.
I have put in new plugs. TR6's. Checked the valve springs and checked lift for a collapsed lifter. It sounds like it's coming from the passenger side.
I have not checked the plug wires yet but it runs fine at WOT.
Any ideas?
Edit, I have HPTuners and can post the tune or make changes as necessary.
Last edited by Exidous; 08-12-2013 at 01:32 AM.
08-12-2013, 03:24 PM
#3
I thought of that too. I had done a compression and leak down about two weeks ago. Shortly after it started. Came up great.
Thanks
I'm going to disable LTFT and DFCO to see what happens. My LTFT are all under 3% anyway.
Edit: No Dice. Still getting the pop. Could a new plug with a .035" gap cause is to not burn enough at low rpm but fine at high rpm?
Thanks
I'm going to disable LTFT and DFCO to see what happens. My LTFT are all under 3% anyway.
Edit: No Dice. Still getting the pop. Could a new plug with a .035" gap cause is to not burn enough at low rpm but fine at high rpm?
Last edited by Exidous; 08-12-2013 at 09:03 PM.
08-13-2013, 11:08 PM
#7
All good ideas. There were no miss fire counts. There is an exhaust leak but it's been there ever since I redid the Y-pipe section about 5 months ago.
I did find the cause(s). I tried opening up the gap on the TR6 V-powers. They were at .035" and I tried .045" and .055" All gave me the same low RPM issues but the higher gap made WOT no bueno as well. I swapped in some new TR5GP's gapped at .041" that I had used before. It fixed most the issues breakup issues but not the popping. I put in new wires despite mine looking like they were in great shape. Car runs great again.
I guess my car just needed new wires and doesn't like the TR6's.
I will try that injector idea to try to find my exhaust leak.
Thanks for the ideas.
I did find the cause(s). I tried opening up the gap on the TR6 V-powers. They were at .035" and I tried .045" and .055" All gave me the same low RPM issues but the higher gap made WOT no bueno as well. I swapped in some new TR5GP's gapped at .041" that I had used before. It fixed most the issues breakup issues but not the popping. I put in new wires despite mine looking like they were in great shape. Car runs great again.
I guess my car just needed new wires and doesn't like the TR6's.
I will try that injector idea to try to find my exhaust leak.
Thanks for the ideas.
