Another 8 with low RPM power loss and occasional rough idle
10-23-2016, 04:30 PM
#1
Another 8 with low RPM power loss and occasional rough idle
Hey all, I know this topic has been covered countless times, & so of course I know the typical culprits of such problems. First thing I did was upgrade to bhr ignition system. Now immediately after that, the car was running perfect again. But about a week later the problems were coming backing, this time shuddering the car trying to accelerate. I found that one of the air intake hoses had gotten moved out of place during the ignition install and a belt was steadily eating through it. Luckily there was an outer rubber tubing over the inner tubing that actually contained the airflow, so it didn't eat through the tubing enough to leak. Again it ran better once I put the tubing out of the belt's way.
Give it another couple weeks... same problems again but milder. One of the intake tubing clamps was not on the plastic nipple as it should've been but was sort of squeezing the tube and reducing airflow... this helped only a little.
Now I don't have shuddering problems anymore except at 70mph+ and that's probably due to needing an alignment. But I do have power loss at low to mid RPMs. I'm hoping my hardest that it's not the C word with my engine... but I will mention my MPG has not significantly dropped, not including before the new bhr ignition and during the stray intake tube. I hover around 17-18.5 with mostly highway and curvy country Rd miles (the roads our cars were built for).
I still have the stock cat on but just got a used bhr midpipe in case it is the cat... but before I do that, I have to wonder if it'd be wisest to take it by mazda first for a compression test. Or, with no loss in mpg, is that a serious possibility anyway? Oh and of course I never baby it, I redline at LEAST once a drive and usually more than that.
TL;DR
I'll just list what I've done so far to remedy the problem for a tl;Dr and have those more knowledgeable than I suggest my next move.
06 rx8 with 93k on it (getting up there)
New bhr ignition (helped briefly)
Replaced air filter (not a hi flow)
Cleaned MAF (also helped briefly)
Also cleaned throttle body (but didn't really know what I was doing)
Rearranged air intake tubes away from belt
Next moves being considered:
removing cat
Compression test
I don't want to blow $100 I don't have on a comp test if I don't have to, but I also don't wanna pull the cat only to find i need to put it back on to bring it to the stealership, or dump more money on nicer performance parts I don't need if I'm gna have to pay for an engine rebuild.
There also could be a leak in my air intake, possibly. Is there any way to check this? I read about spraying lighter fluid around the intake to see if any of it ignites, indicating and locating the leak. But that sounds like a recipe for disaster.
Thanks for all who help!
Give it another couple weeks... same problems again but milder. One of the intake tubing clamps was not on the plastic nipple as it should've been but was sort of squeezing the tube and reducing airflow... this helped only a little.
Now I don't have shuddering problems anymore except at 70mph+ and that's probably due to needing an alignment. But I do have power loss at low to mid RPMs. I'm hoping my hardest that it's not the C word with my engine... but I will mention my MPG has not significantly dropped, not including before the new bhr ignition and during the stray intake tube. I hover around 17-18.5 with mostly highway and curvy country Rd miles (the roads our cars were built for).
I still have the stock cat on but just got a used bhr midpipe in case it is the cat... but before I do that, I have to wonder if it'd be wisest to take it by mazda first for a compression test. Or, with no loss in mpg, is that a serious possibility anyway? Oh and of course I never baby it, I redline at LEAST once a drive and usually more than that.
TL;DR
I'll just list what I've done so far to remedy the problem for a tl;Dr and have those more knowledgeable than I suggest my next move.
06 rx8 with 93k on it (getting up there)
New bhr ignition (helped briefly)
Replaced air filter (not a hi flow)
Cleaned MAF (also helped briefly)
Also cleaned throttle body (but didn't really know what I was doing)
Rearranged air intake tubes away from belt
Next moves being considered:
removing cat
Compression test
I don't want to blow $100 I don't have on a comp test if I don't have to, but I also don't wanna pull the cat only to find i need to put it back on to bring it to the stealership, or dump more money on nicer performance parts I don't need if I'm gna have to pay for an engine rebuild.
There also could be a leak in my air intake, possibly. Is there any way to check this? I read about spraying lighter fluid around the intake to see if any of it ignites, indicating and locating the leak. But that sounds like a recipe for disaster.
Thanks for all who help!
10-23-2016, 06:03 PM
#2
You gonna eat that?
iTrader: (1)
You can try cleaning the ESS and do the 20 brake stomp.
You can get a smoke test or use a little propane torch to check vacuum.
You can get a smoke test or use a little propane torch to check vacuum.
10-24-2016, 05:41 AM
#3
RX-Heaven
iTrader: (6)
You will want to consider replacing the spark plugs as well. Should have been done when you installed the BHR ignition coil setup.
Check to see if the SSV's are working properly. If one is hanging open you will have a low end power issue. They are supposed to open in stages as the rpm's increase for better breathing and if they are open now, too much air is being let in the engine at low rpm's.
Are there any DTC's?
I would also check for a vacuum leak. A smoke machine would be best but a propane torch can be used in a pinch. Starting fluid works as well.
Check to see if the SSV's are working properly. If one is hanging open you will have a low end power issue. They are supposed to open in stages as the rpm's increase for better breathing and if they are open now, too much air is being let in the engine at low rpm's.
Are there any DTC's?
I would also check for a vacuum leak. A smoke machine would be best but a propane torch can be used in a pinch. Starting fluid works as well.
10-25-2016, 10:14 AM
#4
Thanks for the suggestions. I'm gonna check for leaks then start with the ess since cleaning the maf sensor helped a lot. And verx, I actually haven't had a single code thrown throughout the entirety of this situation, even before the bhr kit. And I did already replace the spark plugs when I got the ignition kit, I figured that went without saying haha.
If all that fails I'll check the ssv. I will say that the throttle body butterfly valve did not look dirty at all when I pulled the air box the other day, so I hope that means I don't have to try to get to those other ssv valves.
Also, on a weird note, it seems to run a little bit better now that the weather is cooler. The only other abnormality is that the oil pressure is slightly higher than center according to the gauge.
If all that fails I'll check the ssv. I will say that the throttle body butterfly valve did not look dirty at all when I pulled the air box the other day, so I hope that means I don't have to try to get to those other ssv valves.
Also, on a weird note, it seems to run a little bit better now that the weather is cooler. The only other abnormality is that the oil pressure is slightly higher than center according to the gauge.