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Discussion Starter · #1 ·
Well I replaced my cat with a universal one I got from my friend, it worked absolutely fine for him. The cat is a high flow one that is only like 3 months old. He gave it to me so I thought I'd install it, I need to pass emissions soon. I hooked the car up to a scope to check everything out, thinking it would be just fine, but I was completely wrong. At idle I'm running around 700 HC PPM and 20% O2, I didn't copy down the other numbers. Last emission test I did when the car was stock I had 72 HC PPM at idle. I then proceeded to do the 2500 RPM test, and it was at 1700 HC PPM :freak:
The plug wires are new, I ran the codes and only got 42. (boost solenoid.. i removed it) I never messed with any emissions stuff or fuel pressure or anything. The car runs pretty good, so I'm kinda stumped. I'm really starting to get burnt out on this car and eventually it's going to have to go. Especially if it won't pass emissions. Any suggestions?
 

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Your moniker says "somewhere in front of a cloud of blue smoke". That tells me that your using oil from somewhere? Three places: rings, valve guide seals, and turbo seals. The high HC will also come from being too rich (black smoke). Those are some very high numbers... replacing a Cat will not band-aide the problem. The O2 is suffering also.

If you're using oil from the turbo, the pathway will be "slimed" downstream only.
If you're using oil from the rings, your compression may be low too, and your plugs will be black and greasy. You will have blow-by.
If your valve guide seals are gone, the above applies, but the compression may be ok.

What's your milage? (and typical MX6.com) What have you done to the car?
 

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Discussion Starter · #3 · (Edited)
well the oil burning is from a cracked piston, I know that. I have rebuilt the motor 3 times this year. The engine only smokes after I boost and smokes really bad for a few seconds. It's the 2nd time this has happened, and last time it was 2 cracked pistons, and I have low compression on cylinder #1 so it's the piston. As far as mods, theres a few threads out there. Basically..

VAF relocation
1G DSM bypass
.48/.42 Saab T3 with flange welded to stock manifold
Hard pipes (or most of them)
5th and 6th injectors
Zombie chip
2.5" exhaust w/ high flow cat
190 lph pump w/ rewire

And some new stuff... spark plug wires, '91 miata plugs gapped .030", radiator, hoses, belts, pistons, rings, my life savings, basically a whole new engine. When I first bought the car (171k on original everything) it passed with absolutely no problem.
Like I said I'm getting no codes or anything. I'm stumped.
 

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Detonation cracks pistons. Either you're peaking too high at some point in time, or something is going lean. Really bad news if your pistons are forged. Its easy to crack or melt a cast piston above 10psi of boost.
You will only get codes if a sensor fails, or goes waaaaay out of spec. The Zombie chip changes alot of those operating parameters (no, I'm not knocking Zombie, I don't even have one).
Lack of spark will not crack pistons. Its either not enough fuel or too much boost.

I will have to admit that some of the stuff 'ya all are doing is a little "after my time". I taught automotive for many years, and worked for Mazda when the 1st Gen was new, but never touched on some of the wild stuff I've been reading about on this web site. If Alter Ego was still around, he could fill in alot of answers. Other than that (locally) someone from SD6 or SCPOC maybe...
OEM (stock) is my long-suit.
 

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Discussion Starter · #5 ·
Yeah I've been battling detonation forever. First engine, I had no clue, and cracked 2 pistons. 2nd engine was a head gasket that blew because it was cheap, and finally my 3rd current motor was faintly pinging and before I got a chance to investigate it, bam, it was broken. Put it on the dyno and found out I was running lean after all. I am pushing as much boost that my motor will make (15 psi) on 91 octane with 2 extra injectors, a 190 lph fuel pump, and this ecu chip mapped for 16 psi but apparently that wasn't enough fuel.

As far as the emissions though, I'm gonna swap in a new longblock and hopefully whatever it is that's causing this thing to run so dirty will be fixed along the way. Believe me, I'll be tuning it right this time, on a dyno :)
 

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just curious but how well do the 5th/6th injectors work? i'm just thinking that no matter where you place these things, you will always get uneven amounts of fuel to diffrent cylinders. so you may be running way rich on the cylinders nearest the injector, and lean to the ones furthest away. could this be possible with what you've experienced on your car?
 

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Discussion Starter · #7 ·
Could be possible, I think I'm scrapping the additional injectors and going with an FMU instead. However, on the a/f on the dyno, it showed even with the 5th injector I was running a little lean. The fuel curve is all wrong
 
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Have you considered measuring it with the stock chip back in?

Also, where did you pick up your scope and how much? I like nifty devices that are pointless in my state :)
 

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pointless

you are point less and you have no points other than the one on the top of your head
 

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Discussion Starter · #10 ·
FlySwat said:
Have you considered measuring it with the stock chip back in?

Also, where did you pick up your scope and how much? I like nifty devices that are pointless in my state :)
I will probably swap chips but zombie said he doesn't even know how to change idle fuel maps so I dunno if it'll help.
my college auto class has the scope. It has ignition graphs and everything too. Awesome tool, would cost more than my life if I had to buy it because it's like.. a huge machine. haha
 

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A 16psi pressure spike is enough to blow anything if its lean...
crack pistons, break rings, blow head gaskets, over stress bearings.....parts have their limits.

Have you ever considered just getting something different to satisfy you need for power? It may be cheaper in the long run.

By the way, what is your state? - besides being in front of a blue cloud :p
 
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Silver Misspeller: I believe your thread was more pointless than mine.

Rebel: Damn, I wanted one, that would have been a neat thing to have.

MSGTR: Good to see you back on the 1st gen section, for a while you were only posting in the Australian forums and I really missed your good information. FYI, Rebel lives in Denver.
 

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Discussion Starter · #13 ·
MSGT-R said:
A 16psi pressure spike is enough to blow anything if its lean...
crack pistons, break rings, blow head gaskets, over stress bearings.....parts have their limits.

Have you ever considered just getting something different to satisfy you need for power? It may be cheaper in the long run.

It was actually holding 16 psi but you're right :)

1st motor : 2 cracked pistons
2nd motor: blown head gasket, low compression
3rd motor: cracked piston, low compression

You would think I'd give up by now eh? Well I probably would, but a car with a blown motor isn't gonna get me anything. I have to at least fix it, and if I'm fixing it, why not make it fast? lol. I dunno if I'm gonna follow through with that, but I have to at least fix the car.
I think that 16 psi is too much for pump gas. It is still pinging with 2 injectors and 15 psi and low compression. That showed around 10.5:1 a/f ratio on the dyno with about 12 psi of boost, so I know it has plenty of fuel and is in the neighborhood of 11:1, no way higher than 12:1. Here in CO we only have 91 octane from the pumps. If I get some 100 octane race fuel when I feel the need to push high boost then I think I will be okay. 'Swat you still making those dual stage boost controllers?
 

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rebel2k4 said:
It was actually holding 16 psi but you're right :)
You would think I'd give up by now eh? Well I probably would, but a car with a blown motor isn't gonna get me anything. I have to at least fix it, and if I'm fixing it, why not make it fast? lol. I dunno if I'm gonna follow through with that, but I have to at least fix the car.
I think that 16 psi is too much for pump gas. It is still pinging with 2 injectors and 15 psi and low compression. That showed around ]



I dont know what youve been doing to your car but the cat will not solve your problem,im running a catco high flow cat and 18psi on stock turbo.oh did i say stock injector too.and i still pass emission.for the next 2 years means no emmission for me.and i have never,never blown a motor.and I believe im running more power to the wheel then you.
you need to figure out what the problem is and fix it.it looks like your car is running extremely righ.700ppm is insane.:rolleyes:
 

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Discussion Starter · #15 ·
Um exactly what do you mean? I know that a cat isn't going to richen my a/f up? Do you think I'm stupid?

BTW I put down the numbers in my sig with a compression reading of 55-95-95-100 and 5300 ft above sea level. That's simply amazing, dont care if you disagree or not.

I didn't start this thread to have people tell me I have a problem. Of course I have a problem to be reading 700 HC PPM. I know that. I was just wondering if other people have had any similar problems, not if you're putting down more WHP than me or not. Thanks but no thanks for those comments.
 

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rebel2k4 said:
Um exactly what do you mean? I know that a cat isn't going to richen my a/f up? Do you think I'm stupid?

I didn't start this thread to have people tell me I have a problem. Of course I have a problem to be reading 700 HC PPM. I know that. I was just wondering if other people have had any similar problems, not if you're putting down more WHP than me or not. Thanks but no thanks for those comments.
hey rebel,I dont mean to offend you,im just stating the obvious,if you had blown 3 motors that means you doing something wrong with the car or something is not right.I understand the compression numbers are low,but the catalytic converter will not cause your car to run rich,if the cat is bad,you might fall your co/nox,since the temp will go up from the clog cat resistance.but as for Hc,is either your 02 sensor is bad,high fuel pressure,even your Air system can cause your car to run rich.I mean that rich.or you might have a leak(air/vacuum)somewhere..
Dont take anything offensive since this is a forums and im just stating my opinion.
 

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Discussion Starter · #17 ·
It's okay, I guess that kinda came off wrong because I felt like you were telling me I was dumb.

I'm thinkin after all this cat might be bad. There's 20% 02 and 700 HC PPM, something is not happening inside that cat. Plus it doesnt make any sounds after I turn off the car when it's hot. With almost every cat I've run into, you hear them making little popping noises as they cool. This one does nothing. It's like something isn't right inside. For my readings to be that far off with a good cat I would have to have a misfire or something terribly wrong.
 

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look at some facts first, t3 turbo that isnt meant to be on the car, not only a 5th injector -but a 6th as well, zombie chip that isnt meant to be in the car, boost solenoid that has been removed, and a bypass that works differently than the stocker. It doesnt take a genius to realize that parameters are going to be off. I'm not sure how your emissions are there, but here in California, those parts arent even allowed on your car, and everyone knows not to roll up at a sniffer with a 5th injector, let alone a 6th. Messing with emissions is a fine in the multiple thousands of dollars, and by multiple, I mean $25,000 range

Not saying anything against you personally, but like I said, it doesnt take a genius.

Obviously you/and everyone else would lik to pass emissions with their aftermarket parts, but you have to face the fact that it 1) won't happen 2) is going to be VERY difficult

my advice is simple

stock boost
stock chip
stock solenoid
stock turbo
stock everything

I know it sucks but, you'll probably pass
 

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Discussion Starter · #19 ·
Well thanks for the advice. I have a buddy that lives in a county near me that said I can register my car there, and that means NO emissions :)
If it's possible then I'll do that, if not looks like I'll be rolling up the sleeves and swapping some parts, possibly for good.
 

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You can get race gas @ Bandemier, but its not cheap.

SixSick6: This is more your territory than mine when it comes to lots of mods. In Colorado, the smog check rarely ever raises the hood, and they have many non-containment areas that don't require a check (low population).

Flyswat: I didn't move to Australia :D I'm still here in So Cal... I can deal with stock issues, smog, and 4WS, but I am totally "out of the loop" when it comes to the wild stuff I've seen everyone do to their cars in this web site - its an eye opener for sure! I'll stick with the mild stuff, or my husband will divorce me when I break his beloved car. @-

I will be in Denver between Christmas and New Years. You want me, look for me @ Winterpark :p

Hang in there Rebel. You're in a learing curve.
 
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