As a continuation of my last thread, I apparently can't change the title - but new issue, new thread if you ask me.

I have a Mazda reman engine with approximately 56k miles on it. It came out of my old rusty car where it was running with no issues, into my new clean car. With the engine swap, I replaced the coils and wires with the BHR system, replaced the plugs shortly after when it started giving me trouble starting when hot. I also installed an RB dual resonated midpipe, so there is no cat to be clogged.

I found about a quart of oil in the intake. I ran two cans of brake clean down the intake, cleaning it completely. I figured the MAF sensor to be fouled since it was also soaked in oil and MAF cleaner had little effect, so I replaced it. I tested the car with my old coil packs to be sure the BHR system wasn't giving me any issues - they weren't.

I took the car for a ride last night to see if my lingering stall at idle issue was relieved, and it seemed to be. The car ran fine on my way out to the halfway mark. 30 minutes in I had half a tank of gas and wanted to run a bottle of Techron fuel system cleaner through it, so I filled up (engine running as I wasn't sure it would start back up yet) and took off. As I hit the highway I tried to redline but the car seemed to hit a wall around 7-8k and misfired, so I backed off and cruised. I tried a couple more times to hit redline with the same result, and the last time I backed off into sixth the car did not respond to the gas pedal, and I could hear a kind of scraping noise coming from the engine bay as the RPMs slowly dropped. The second I hit the clutch pedal, the engine died so I pulled off to the shoulder. Trying to restart the engine resulted in a very slow crank, like a dying battery would produce. Had it towed to my work.

Today, I charged the battery with a heavy duty rapid charge unit set to 10A. Battery charged to 13v (it's a five year old Optima red top) and cranking speed was better, but not good. It took probably fifteen seconds to start, had to cut fuel with the accelerator for a couple seconds to make sure it didn't flood, and it stayed on with my foot on the clutch but idled cold at 750rpm, very lumpy like a V8 with a heavy cam, with a strong gasoline smell. However as soon as I let off the clutch, it cut out.

Several hours later I tried to start it again before leaving work. It started again after excessive cranking, revved to about 1500 with the same lumpy sound, let out a bunch of white smoke and eventually died out after a minute or two. It threw a p0506 along with the pending p0302 and p2096 that had been present before. I left it at work.

I'm beyond stumped. Did my own work on these cars for 5 years now and never had an issue like this that couldn't be solved by the usual suspects. I did break the top vacuum line on the intake (near the butterfly valve) pulling it out one time, but glued it back together as best I could - I have no idea what it actually goes to though.

To recap, I have replaced:
• Fuel pump (not mentioned, but yes it's brand new - 255lph unit)
• BHR ignition kit
• Plugs
• MAF sensor
• Reset ESS w/ 20 brake stomp
• Disconnected battery several times working on it

I'm hoping the apex seals aren't shot but fearing the worst. Lay your suggestions on me and I'll try my best to get a look at it.

 

Engine Power Loss
• chokes as revs increase
o O2 sensor failure (too rich)
o MAF failure
o MAF disconnected
o e-shaft sensor fouled
o accessory belt fraying
• high end power loss (hard fuel cut)
o Rev limit reached
• high end power loss (jerky and stumbling)
o Ignition failure
o fuel pressure loss
o e-shaft sensor fouled
• high end power loss (smooth)
o Catalytic converter clog
o air filter clog
• low end power loss (smooth)
o Engine compression loss
• low end power loss (stumbles)
o Ignition failure
o front O2 sensor failure
• revs slowly but smoothly
o O2 sensor failure (too lean)
o catalytic converter clog
o air filter clog
• sudden power drop at a specific rpm
o Intake valving actuation problem
• trouble getting to redline
o Ignition failure
o front O2 sensor failure
o catalytic converter clog
o air filter clog
o e-shaft sensor fouled
o fuel pressure loss
o MAF failure

P0506 Idle air control system RPM lower than expected ON 2 CCM ´

P0302 Rear rotor misfire detected Flash/ON 1 or 2 Misfire ´

P2096 Target A/F feedback system too lean ON 2 Fuel system ´

 

I have RIWWP's thread with that information bookmarked actually, thank you.

I know I have yet to check the ESS for dirt, and the air filter isn't choking anything out. I did forget to mention the car threw a rich code at some point but I don't remember which one. But I don't think the O2 sensor is bad, I'd be very surprised if it were since it's relatively new within the last few years.

 

I'm trying to think what else would cause a scraping sound besides a loose seal or some sort of piece of metal in the engine

Maybe you can remove the leading plugs, put it in neutral, and turn it by hand to get a look through the leading plug holes at each of the 6 apex seals. If you see that one is missing or bent, you'll know for sure what the problem is.

 

How would I turn the rotors by hand? Is there a nut on the outside of eccentric shaft I can turn, or another method? That's a new one for me.

Edit: Found a thread with a reply by RIWWP. Will try turning via main pulley and see what I get if I get a minute at work.

 

Chambers look dirty but the seals aside from one don't look bad to me. They do appear rounded off, and one is not shiny like the rest. I took pictures, I know generally what I'm looking for but actually seeing the seals outside of video is a first for me.

Pics here: https://goo.gl/photos/jRrSnSMeVbKqxkBQ9