Very slight idle stumble
#1
Registered
Thread Starter
Very slight idle stumble
Is it normal for our engine to vary in idle slightly? From about 780 to 900rpm . Every 10-20 seconds it settles down (it doesn't drop) to around 780 rpm and sits a second or two then drifts back up to around 900rpm. Also a slightly sluggish blip of the gas at idle makes it hard when at at stop on a hill. Any thoughts.
Note:
this engine only has around 700km on it.
Bennet built coil upgrade
Gutted cat
Mazda speed cai
Note:
this engine only has around 700km on it.
Bennet built coil upgrade
Gutted cat
Mazda speed cai
#3
Registered
Thread Starter
Ac? I got rid of that. Don't really need it around these parts. And no nothing else is on and the batt is a red top and only a couple weeks old. I doesn't effect driving except for the slight delay in response from a stop. Again I'm talking miniscule delay. I find it's not there when the idle is at the higher point. Is there anything I can do to make it idle around 950rpm. Besides ap since I don't have one. Has anyone tried to sand the edges of the flap in the throttle body the allow for tiny more air at idle. I have two working TB so I can experiment lol.
#4
Registered
iTrader: (1)
How did you get rid of A/C? If the compressor is still connected and has a belt on it it might think it's still using it. Even if the rest of the system is gone.
Because this blipping sounds EXACTLY like normal AC cycling.
There shouldn't be any delay even at 750 rpm though.
Because this blipping sounds EXACTLY like normal AC cycling.
There shouldn't be any delay even at 750 rpm though.
#5
Registered
Thread Starter
How did you get rid of A/C? If the compressor is still connected and has a belt on it it might think it's still using it. Even if the rest of the system is gone.
Because this blipping sounds EXACTLY like normal AC cycling.
There shouldn't be any delay even at 750 rpm though.
Because this blipping sounds EXACTLY like normal AC cycling.
There shouldn't be any delay even at 750 rpm though.
#6
Water Foul
Are you looking at the RPM gauge or a phone app? The RPM gauge stays pretty steady, but a phone app will show something like the variance you describe.
#7
Registered
Thread Starter
Both obd and the rpm guage shows it. There is a small shake when its on the lower end of it. Around 800rpm. But a lil higher and there is no delay and is smooth as can be on take off.
#8
Registered
Join Date: Mar 2014
Location: Orlando and occasionally Miami and San Diego
Posts: 23
Likes: 0
Received 0 Likes
on
0 Posts
I know someone who used MazdaEdit (I think) and adjusted his idle to 900-950 and its super smooth. It is also a Pettit Built engine so theres that
#9
Registered
Thread Starter
I do not have a cobb so I can't change the tune. I'm still debating on trying to file down the edges of the flap in the throttle body. I don't think it would take much to get idle a little higher. Or if it would make the idle higher at all. The ecu will probably just calculate that extra air and dial back trims.
Last edited by Red line envy; 08-18-2019 at 04:09 PM.
#11
Registered
Thread Starter
#12
No respecter of malarkey
iTrader: (25)
No, the OE system is going to try and maintain the set point in the program software. The issue at OE idle is oil pressure. The alternative to that would be to modify the oil pressure regulator. Mazmart sells that. It won’t change your idle situation though. You’ll need programming software for that if you also need OBD2 emissions compliance. Otherwise an aftermarket ECU like the Adaptronic Select could also be used.
Last edited by TeamRX8; 08-19-2019 at 09:51 PM.
#13
Registered
Thread Starter
I'll probably up the oil pressure and get a Cobb when I can
Thread
Thread Starter
Forum
Replies
Last Post
szjalo
RX-8 Discussion
5
07-25-2011 07:13 PM