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'95 Hunter Green LS 5-Speed
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Discussion Starter · #23 ·
No new pics, but a few updates:
  • Parts coming in for a full EGR system replacement (valve, solenoids, vacuum lines).
  • Have replacement O2 sensors also (I'm not digging up behind the engine more than once).
  • Got her registered yesterday. Nice discovering that dealer prep, doc and shipping fees are all taxable. :mad:
So after a few weeks with Megumi, here's a running list of things I appreciate about the car's design (read: things they did but didn't have to):
  • Inboard fuel tank (lower polar moment of inertia).
  • Independent rear suspension.
  • Rear disc brakes.
  • 60/40 folding rear seat back.
  • Left side cupholder.
  • Proper 3-spoke wheel w/thumb grips.
And that's not even getting into the actual styling, which is very much the car's selling point... More to come!
 

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'95 Hunter Green LS 5-Speed
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Discussion Starter · #24 ·
✅ Replaced the whole EGR system: Valve, lines and solenoids.
✅ Installed intact radiator overflow tank + new cap.
✅ New PCV valve.
✅ New O2 sensors.

I had to drop 1) the exhaust up to the cat and 2) the whole farking rear exhaust manifold b/c there was so little room behind the engine to separate the EGR unit.

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The EGR valve was actually a bit of a successful hack job. So, a normal replacement runs $400+ (!!) from RockAuto. I found this unit for $60 BUT the connector is female and a different shape than the male connector on the car's unit. I performed a neat splice into the wiring harness, and...lo and behold, it works!

Megumi is error-code free! No VRIS codes, no FPR codes, no EGR codes. Feels good!

....but the misfire is still there. :mad: So close! Going to reset the TPS, time the engine and maybe replace the spark plug wires next...
 

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'95 Hunter Green LS 5-Speed
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Discussion Starter · #26 ·
Thanks! I went in through the bottom b/c I didn't want to have to deal with reattaching all the vacuum lines, although whenever I disconnected one, I did replace it with its 4mm silicone equivalent. Also I didn't have a 23mm flare nut wrench for the EGR line, so I think the valve + manifold was going to have to come off anyway... All's well that ends well though.

There's a tapping sound from the front left that wasn't there before the repair. Sounds like either swaybar bushings or maybe a blown shock. Bushings + endlinks on order, as is a set of NGK spark plug wires. Potential clue to the misfire: The front O2 sensor was a lot sootier than the rear one, so I have a hunch one of the cylinders on the front bank is marginal, whether b/c of a bad plug wire or maybe a clogged injector. Will keep you posted.
 

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'95 Hunter Green LS 5-Speed
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Discussion Starter · #27 · (Edited)
Somebody followed (carried, actually) me to work today for the first time.

She did great. Still got the misfire, but she's still got enough pick up. My commute is 20-25 minutes of 60/40 suburban/highway mixed driving, and she handled it all like a champ. Opened the sunroof and enjoyed the fall breeze wafting through the interior on the way home.
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Got a very high estimate over lunch for the PDR she needs. Going to shop around a little more...
 

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Discussion Starter · #28 ·
A little progress to report. Installed a set of NGK plug wires:
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These are the way to go. EXACT fit, very high quality. Seems to have smoothed out the engine a little bit.

The car has good power and actually smooths out more past 2K or so rpm. I'm to the point where I'm wondering if it's just the natural frequencies of the V6. I've been spoiled for years by the total smoothness of my E46's I6. Going to actually time it this weekend and see if that helps any more.

In other news, I replaced the dash backlights. 5 large and 1 small bulb. The dash trim came out ridiculously easily. 3 screws and my trim tools and off it came:
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Done and done:
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I took the opportunity to repair a crack in the trim at the lower right corner of the headunit. I used epoxy and a piece of stiff wire to reinforce the joint:
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It was cracked through in two places, but you can hardly tell now:
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Onward!
 

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'95 Hunter Green LS 5-Speed
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Discussion Starter · #29 ·
✅ TPS set.
✅ Idle set at 650 rpm.
✅ Timing at 11° BTDC.

She runs really, really well. The throttle tip-in seems to have improved and she has ample power. Some very slight residual shuddering in certain regimes, but as noted above, that might just be the natural frequencies of the V6. My E46 would drive circles around her, but that's expected from 60+ more horsepower and a newer BMW chassis in a good state of tune.

Next goals: Pulling off the door panel to see if I can re-glue the insert, 3D printing a new door cup/pull and the PDR appointment on the 24th.
 

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It sounds like you have become fond of this car in a short period of time. I replaced my spark plug wires last month, and as you mentioned they smoothed out the engine a tiny bit. When you get the timing exact, the engine is very smooth. Mileage around 25 mpg. With time and enough tools, I have been able to figure out most things on this car. One item I have not been able to correct is the fuel gauge does not show the correct amount of fuel. It can't be the instrument panel, as I have tried 2 different ones with the same result. Fuel pump replaced not long ago. I would have no idea how to trace a wire from the wires that clip into the back of the instrument panel.

I had a KLZE engine for a while, and went back to a KLDE. The KLZE has more of a feeling of effortless power, while the KLDE is more fun to drive with, especially around the 40 to 75 mph range.
 

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Discussion Starter · #32 ·
Sounds like the fuel level sending unit could be flaky, but you'd likely have to drop the tank to replace that. Not a small job...

Interesting about the ZE vs. the DE. What is it about the DE that makes it more fun to drive? Does it rev more readily?

Decided to try to clean the injectors earlier. Pretty easy to remove the fuel rails.
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A little disappointed to discover the injectors are side-feed, which meant I couldn't cycle them and spray straight through. I did what I could though re:cleaning.

Also, I had to get creative with some stiff wire to fish the fuel rail spacers out of the V when a couple inadvertently dropped down there.
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Got everything reassembled, and.....she runs worse now. Also, there is what appears to be raw fuel coming out of the tailpipe in white puffs, so maybe my cleaning efforts caused an injector to stick open? I have some reman replacements on the way for delivery Wednesday. Stay tuned.
 

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The KLDE is more fun for me as you still get some climbing sensation as it increases revs and reaches speed. With the KLZE engine it was effortless power. I guess that is good is you want to go faster. Kind of like the supercars now that reach 60 mph in 3 seconds. I replaced the fuel pump a short time ago, as sometimes the car will cut out completely going around a corner fast and a few other symptoms of a bad fuel pump. The fuel gauge was bad at this time also.....but still moved around and had current. Since they attached the fuel sender to the new fuel pump, I thought that would have solved any problems there in the fuel tank....but no change to the fuel gauge....but a lot better with the new fuel pump.
 

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Discussion Starter · #34 ·
The KLDE is more fun for me as you still get some climbing sensation as it increases revs and reaches speed. With the KLZE engine it was effortless power. I guess that is good is you want to go faster. Kind of like the supercars now that reach 60 mph in 3 seconds.
Yeah that's not what the MX-6 is about. Anyone who gets one expecting to win drag races is really barking up the wrong tree, IMO. I actually like a smaller, revvier engine. My E46 has, as you say, effortless power, but it's not as rev-happy and fun as the M50B25 in my old E34, somehow.

Got everything reassembled, and.....she runs worse now. Also, there is what appears to be raw fuel coming out of the tailpipe in white puffs, so maybe my cleaning efforts caused an injector to stick open? I have some reman replacements on the way for delivery Wednesday. Stay tuned.
Pulled the fuel rails off again (now that I know what to do, it took me about 15 minutes), and...eureka?

Injector for #2 is dead. No resistance, no click when jumped (all others 12-16 ohms per spec). Would explain the "misfire" feeling of a dead cylinder.

Also the lower o-ring for #6 is ripped. Would explain the white puffs of raw gas out the tailpipe last night.

Hopefully the reman injectors solve both issues. I also plan to do a precautionary oil change just in case some raw fuel leaked past the rings into the sump and is diluting the oil.
 

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Discussion Starter · #36 ·
So, good news and potentially bad news.

Good news: The remanufactured injectors completely fixed the misfire! The engine runs buttery smooth now in all regimes and has some pretty good pickup, especially in 2nd and 3rd! Very impressed.

Potentially bad news: The white smoke still hasn't gone away. I'm having a hard time identifying its smell. It smells a little sweet, but also a touch oily and burnt. The only things that keep me from definitely suspecting a head gasket are:
  1. The engine doesn't overheat at all and I'm not losing coolant.
  2. It started immediately after I cleaned the injectors. Before that, there was no smoke whatsoever.
It seems to be somewhat intermittent also, and less now that I've driven her around 5-10 miles. But it's still there. Going to do some more investigation tomorrow when I have daylight.

Worst-case scenario is a head gasket job, which doesn't look too expensive or tough. Annoying to be so close, though...
 

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Discussion Starter · #39 ·
A little hard to tell, but it looks like the spark plug wires for # 4 and #5 cylinder are reversed.
Nope; they're all in the correct locations.

* * * * * *

So, long weekend of car work. Report:

Someone on another forum suggested my issue may not be a head gasket, but might be the coolant-cooled EGR valve, which I recently replaced. The diaphragm may have ruptured, allowing coolant into the exhaust.

And...it turns out that's exactly what it was. I capped off the EGR coolant and vacuum lines and bypassed the lines between the thermostat housing and the TB, and...no more smoke (after the residual burned off, at least)! I'm getting a CEL and EGR code 16, as expected, but that doesn't affect how the car runs. I took the opportunity to do a full coolant flush & oil change and replace the thermostat and its o-ring and gasket as well.

So happy to not have to replace head gaskets. Dodged a bullet there.

Evening Megumi:
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From the photo, the # 4 cylinder wire sure looks like it is on the middle prong of the distributor cap, where it should be on the one at the front. And the # 5 wire looks like it is on the front, and should be on the middle.

4 5 3 and 6 1 2
 
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