Yeh, I think Cams rite, it was your clutch cooking id imagine, it would explain the DSC and also since it was slipping so bad it probly overheated then blew. I hope to god that its the only problem.

 

Denny, I may have blown the clutch, but I wasn't doing anything remotely abusive at the time. I was doing 40-45 mph in 3rd gear on neutral throttle. I've never done anything to abuse the clutch; no drags, no racing, no stupid ****. The PCM was on from when I went left the garage since I had the battery disconnected. Up until the explosion, which was in the intake manifold, there was no problem with the clutch or transmission, car shifted smoothly, clutch was normal. After, the clutch stayed on the floor, I think the explosion damaged the clutch cylinder, and, of course, without ground and tranny speed sync, no wonder I couldn't slide it into gear. The entire episode lasted 10, 15 seconds tops, from OK to No-K. I'll know a little more in a couple days


Why did the DSC think I was on a slippery surface? No clue. The battery was disconnected when I changed the injectors, and when I hooked it back up, I had the DSC light.

BTW, I want to make it clear, this is not a Pettit problem. It's either my bad or a Mazda bad, but I don't see it as being a problem with the S/C system.

 

I don't think the 09 injectors are that big of a mismatch for this setup, especially with the larger pulley. I've beaten myself already thinking I didn't get the injectors in the rail properly, but dammit I triple checked them before, during, and after re-installing the fuel rail, and then rechecked them after I did the ECU room fuse/idle reset, and there were no leaks. None. The car idled perfectly, ran through the gears well, but when I got on the gas in 3rd at 6k, it fell flat on its face, owing, I thought, to the DSC being active. Then I see 20 degrees of timing retard with large TPS values and figure that's the DSC at work; trouble is, at those points, the lamba is stil within ranges, so fuel is still being delivered, but not burned completely. After I realized the DSC or something was holding it back, I didn't try to romp on it any more, just wanted to get a feel for how the car was running. Took a total of three miles for it to grind to a dead halt.

 

He may be right, I haven't considered the clutch up to this point, but a clutch blowing up makes a different sound than an intake backfire, and doesn't bow the hood up 6 inches. Usually there is a little trail of tinkly parts left behind, and I checked, that wasn't the case either. I'm fairly sure whatever happened happened inside the motor/exhaust. The question is, what.

 

Plugged cat, and a broken Apex seal?
It sounds like fuel was being sprayed and did not go into the engine, then a spark hit the mixture.
Another thought: "Vacuum" tap comes loose, boost pushes air and fuel out (the stumble), then boom.

Are you sure your fuel injectors were wired correctly?

You were not running NOS; were you?

 

First, No NOS.

Second, absolutely positive the injectors were wired correctly; I numbered the connectors before I pulled the injectors from the rail, even numbered the rail to correspond. I suppose it is possible that the vaccuum tap cam loose, I honestly doubt it. Also, I'm confused about that one; if the tap cam loose, how did fuel come out? The tap is on the inner aspect of the UIM, the injectors deliver fuel below the LIM; if the tap did come loose, the car would run like crap for sure as it leaned out, but I didn't get a CEL before the big bang. Apex seals, can't honestly rule that out yet, but the car only has 24.500 miles.

I'm pretty sure the fuel went into the engine; it's what happened after that I'm trying to verify. Next questions?

 

NOS isn't flammable. So unless the detonation was from over pressure in the rotor housings (which doesn't seem like it was) I don't think it was NOS--as in a leak of NOS out of the system or what not.

It could have accelerated a small fuel leak if they were both present in the intake... but I don't know how they would both end up there?

 

Boost pressure can push out of a vacuum tap, if that tap is below the injectors, like the two on the passengers side of the lower intake down low, or the one on the bottom of the lower intake that connects via a short vacuum hose, below those two visible ones.....

Any leak from the lower intake (below the injectors) could leak air and fuel under boost.

OTOH: Cam is usually right on anything Mazda.

 

I think Denny's ideas sound resonable,,,
And of course Moon mentioned what happened to me but that was at 120mph and I hear a big bang, a huge plum of smoke shoot out the exhaust and a boost spike of 15psi (again 5th gear moderate pull at 120mph), but it sounds like you were just cruisin at a safe speed,,,,
You said the car was sitting for a while????
I wonder if that had anything to do with it along the theories of fuel build up,,,,

Were you in between shifts? what rpms were you at?...

 

Denny is thinking along the same lines as I have been; spent all weekend watching Rolex Series race at VIR watching the '8s when that process occurred to me. The most obvious answer is that I screwed something up, but the fact that I was so careful about make certain everything was installed properly kept nagging at me, and if I hadn't seated an injector in a rail properly, I should have noticed or smelled it when I idled the car. Whiskey Tango Foxtrot.

The car had been sitting about 2 months - usual bad winter weather. I wasn't between shifts, was cruising steady throttle about 40 mph, maybe 3K rpm.. Yes, I agree a LIM leak would allow fuel to leak out, it's the only other place, funny it would choose to show up now, who know. The LIM has never been off.

I don't know if the car having sat for a while had much to do with any fuel build up. After I installed the injectors, I did an ECU reset by letting the car sit and idle until up to operating temp, then holding at 2K, 3K, and 4K rpm for 10 seconds each, the shut it down. It idled smoothly as always during the reset, and I checked for leaks, loose hoses. There were no leaks, no smell of raw gas, either in the engine bay or from the exhaust. I did the reset in the garage, so I got a goo sniff.

Here's one other issue: recently there had been some discussion about the potential dangers of a clogged cat. I had begun to suspect that my stock cat might be going; the car didn't seem to have quite the punch I remembered when the S/C was first installed, but it didn't throw any codes so I kind of back burnered the thought. So now I leave with new injectors and a larger pulley and questionable cat; throw in 20 degrees of ignition retard thanks to the DSC and there's the potential for a lot of unburnt fuel to make it to the cat; I think that's why the car stalled when I turned around in a parking lot; the cat was starting to get hot and plugged. Just a little farther down the road and the cat loses a piece and obstructs; raw fuel ignites and blows back; that with the blower pushing, albeit at very low boost, and bang, there goes the boot connecting the blower and the UIM. Beyond that, I'm not sure. Hell, not even sure about that. The only thing I do know for certain is that the injectors were in tight and there were no fuel leaks when I left home, but 3 miles later, bam.

Any further diagnosis will have to wait 'til Moon makes it up here; she'll sit until then. And yeah, I plan on calling Cam too, and let me say again, this problem is either my fault or a problem with my car, not with any Pettit gear.

 

I think more consideration needs to paid attention to the ABS,,, Especially since you said it went AWALL just before and after the incident....
WE all had to cut the outer bracket of the ABS system,,,, and this is really way out in left field but what if something jarred loose an electrical connection, this partnering with re routing the fuel lines, I wonder if somehow you had open current which somehow ignited a fuel line,,,
Way out in left field but who knows....

 

Bittersweet news Zen,

I ran all written data last night on my state-of-the-art computer and here is your car diagnosis. You have a clogged catalytic converter and a broken clutch disk. Exhaust gases where not able to escape at optimum “speed/flow” hence stalling/catastrophically reducing the engine revolutions per minute RPM while the car was in gear. Therefore, luckily your clutch disk became the weakest link between the flywheel and the drive train. BTW, I’m just writing exactly what the computer monitor says since my Polaroid camera does not have the capability to focus past 1X.

 

The one thing I would like to add deals with combustion. You said there was an explosion? A large explosion. That means that either you had a lot of back pressure or a lot of fuel ignite.

If the cause of the boom was a fuel leak igniting, the only thing that would cause an explosion like that is vapor--not liquid--gasoline. So the fuel must have been able to vaporize or pool in one spot before it could have been combusted. I think it would take either a fairly large amount of vapor to explode in the manner you described, or a very small amount in a highly pressurized location.

I think it rules out fuel lines.

 

^^

...that seems to fit to me.

 

 

the good thing is you are ok, zen! Hope you get to the root of it....

 

I had an incident with a clogged cat this past summer, but all my car would do is intermittently stumble/stall for no reason that was apparent at the time. After a week of this, I decided to take off the cat pipe. Immediately after removing the cat pipe I could hear that something was loose inside.

Looking inside of it, I noticed a huge chunk of catalyst material was loose and was just the correct diameter to prevent it from moving out of the end of the pipe. I immediately took a long screwdriver and hammer to it, and have not experienced the problem since.

My suggestion is that you jack the car up and take off the mid-pipe and see what you have.

 

Well, I failed to mention the the 09s come with only 1 bracket holding the ABS unit.

 

Damn, Juan, I wish I'd known your degree of electronics sophistication before I solicited your advice

 

Did I mention ABS? Or DSC? All these letter confuse me

 

Should be able to get at it in a couple of days.

 

The only time a clutch explodes is under excessive load - so I'm picking it is nothing to do with the clutch and everything to do with the recently installed injectors ........................

 

Ill put my money on the CAT cause it blew the coupler from the intake to the I/C. I bet theres a cork in the CAT.

 

/\ how does a backfire in the exhaust find its way into the UIM ?

 

If you meant exactly what you wrote, you, sir, are a moron.

If you are trying to make a funny, you failed at that as well.