6000+ rpm roughness

sv51macross · 11-27-2010, 10:08 AM

Beginning around 6000 rpm the engine feels kinda rough, rough like I know a rotary isn't supposed to feel. Below 6K the engine is just fine, idles fine, ect. But above 6K...certainly backfires like a RX should.

Ideas?

-Front rotor has likely been getting very little oil for the last several thousand miles (previous owner repaired broken OMP lines with rubber sleeves). But...the car runs smoothly and isn't rough at low RPM like I understand a bad apex seal is supposed to feel like.

-Said OMP lines have been leaking all over the right-front subframe and that engine mount has been soaked.

-Trans mounts need replacing too.

NoDOHC · 11-29-2010, 11:58 PM

If you are not injecting oil, you should be premixing.

You could have any number of problems, but you should verify that your VDI is operating correctly.

How new are your plugs and wires?

By rough, you mean that it is misfiring, or just shaking? It is possible that there is enough carbon buildup to make it out of balance (although I have never seen that). If it is misfiring, check the ground on the MAP sensor, the connection to the AFM, the TPS adjustment and linearity, plugs/wires and the VDI as previously mentioned. If it is not misfiring, you may have carbon buildup (which should be removed).

sv51macross · 12-06-2010, 10:04 PM

Sorry for the lateness, out internet s*** the chicken. Don't worry, injecting oil now (at least three of four. Premixing anyway).

Well, another discovery, the Aux ports aren't coming online like they should. Seriously thinking about dumping the actuators and air pump though, I removed the actuators and rolled the aux ports open by hand. Then took a couple trips around the block...wasn't that bad.

It could be misfiring, as she often misses while idling (not regular, like hiccuping at irregular intervals), but still, it gets real smooth 3-5k. Certainly a possibility though, I've been wanting to for awhile. (Where is the block-body ground, BTW?)

11-27-2010, 10:08 AM	#1
sv51macross Rotary Fan in Training Join Date: Oct 2010 Location: Ann Arbor, Mi iTrader: (0) Posts: 47 Rep Power: 0	6000+ rpm roughness Beginning around 6000 rpm the engine feels kinda rough, rough like I know a rotary isn't supposed to feel. Below 6K the engine is just fine, idles fine, ect. But above 6K...certainly backfires like a RX should. Ideas? -Front rotor has likely been getting very little oil for the last several thousand miles (previous owner repaired broken OMP lines with rubber sleeves). But...the car runs smoothly and isn't rough at low RPM like I understand a bad apex seal is supposed to feel like. -Said OMP lines have been leaking all over the right-front subframe and that engine mount has been soaked. -Trans mounts need replacing too. __________________ 1990 Mazda RX-7 NA; Lucy, after the main antagonist from Elfin Lied. Eventual plans? Something cyberpunk and spicy.

11-29-2010, 11:58 PM	#2
NoDOHC The quest for more torque Join Date: Sep 2008 Location: Sheboygan, Wisconsin iTrader: (1) Posts: 855 Rep Power: 17	If you are not injecting oil, you should be premixing. You could have any number of problems, but you should verify that your VDI is operating correctly. How new are your plugs and wires? By rough, you mean that it is misfiring, or just shaking? It is possible that there is enough carbon buildup to make it out of balance (although I have never seen that). If it is misfiring, check the ground on the MAP sensor, the connection to the AFM, the TPS adjustment and linearity, plugs/wires and the VDI as previously mentioned. If it is not misfiring, you may have carbon buildup (which should be removed). __________________ 1986 GXL ('87 4-port NA - Haltech E8, LS2 Coils. Defined Autoworks Headers, Dual 2.5" Exhaust (Dual Superflow, dBX mufflers) 1991 Coupe (KYB AGX Shocks, Eibach lowering springs, RB exhaust, Stock and Automatic)

12-06-2010, 10:04 PM	#3
sv51macross Rotary Fan in Training Join Date: Oct 2010 Location: Ann Arbor, Mi iTrader: (0) Posts: 47 Rep Power: 0	Sorry for the lateness, out internet s*** the chicken. Don't worry, injecting oil now (at least three of four. Premixing anyway). Well, another discovery, the Aux ports aren't coming online like they should. Seriously thinking about dumping the actuators and air pump though, I removed the actuators and rolled the aux ports open by hand. Then took a couple trips around the block...wasn't that bad. It could be misfiring, as she often misses while idling (not regular, like hiccuping at irregular intervals), but still, it gets real smooth 3-5k. Certainly a possibility though, I've been wanting to for awhile. (Where is the block-body ground, BTW?) __________________ 1990 Mazda RX-7 NA; Lucy, after the main antagonist from Elfin Lied. Eventual plans? Something cyberpunk and spicy.