TechSmurf

Hmm.. I started my account here about 7 months ago to help out a friend who bought an '87.. oddly enough, he gave up and gave me the car after it died on him on the highway.. so here's where it stands:

This evening I finally decide to actually take a look at it.. no combustion. I pop the plugs.. they're fouled beyond belief.. clean 'em up, toss 'em back in. It eventually starts.. barely.. runs crappy as hell, won't idle, the exhaust fumes are straight up noxious (burning eyes/nose), smoke show, barely produces enough torque at WOT to rev itself up. It's done this to my friend a few times, so I give it a minute to warm up and see if it starts behaving like it did for him.. nope.. bah. Glance under the car, exhaust is glowing bright red/orange between 1' prior to and 2' after the cat.. and I notice a small patch of carpet in the car smoking slightly. Shut it down, sprayed down the exhaust with a garden hose (I know, not healthy, but between killing the exhaust and burning the car down, I'll kill the exhaust), spray down a small spot of the interior (which sizzles.. yike), it's fine.....

From searching/reading here, either
1: the glowing exhaust/total lack of power suggest either the cat(s) is/are toast and/or she's running on one rotor (fuel afterburn causing glow)
2: from the hard flooding starts I'm assuming I've got leaky injectors (again, fuel afterburn causing glow), but I can't figure out why this would zap the power that horribly
3: Could the AFM be that level of toast? I haven't fabricated an ECU diagnostic setup for it yet.. on to-do list.

I'm probably going to start with brand new plugs and cat removal, but I'm highly open to input at this point. The plugs had been replaced by my friend, and it did help, but things have gotten worse than they were when he bought it.

82_annrx7

Sounds like your on the right track with the cat being clogged. I would get a compression check first before doing anything else.

TechSmurf

Hmm.. yeah.. probably not a bad idea.. should have a tester available down the street, though I don't know anyone in town with a rotary tester, so even if it shows compression, it'll be inconclusive.. if it shows bad, though.. well.. heh. Always wanted to rebuild a motor with less moving parts than you can shake a stick at

Brad89RX7

Cat's sound clogged, one test is to take out the O2
sensor and see if that relieves some back pressure.
You might get a better Idle. But I think if your carpet
is smoking you have melted the Cats. The cheapest I've seen
stock Cats is Victiria British, about 179.00 per Cat.

TechSmurf

... almost 200 per cat? Ouch. Oookay.. well.. test pipes it is till the thing's running at 100% again. No smog ***** where I live, but I do like the idea of being able to breathe outdoors in 20 years.. no point in melting new cats though.

Templeswain

no point in melting new cats though.


I doubt that you'll melt the cats again. Once the cat gets clogged then it builds up exhaust and keeps it there like an oven because the waste is not able to escape correctly.

Since its an 87, I would not be surprised that they're clogged.

If you're going to pay 200 bucks per cat, just get a RB down Pipe and presielencer for almost exactly the same cost. Then later you can get the mufflers.

Much better buy then just getting some aftermarket cats that will probably be harder to install.

Here's a price list and info:

http://www.mazdatrix.com/pictures/racing/r8-c.jpg
$200

http://www.mazdatrix.com/pictures/racing/r8-h.jpg

$200 also.

TechSmurf

My primary dilemia is getting it running with as little $$ as possible. If the motor is completely toast, I'm not going to be able to afford another 13B anytime soon. It'll be a week or so before I get her in the air for the exhaust work, so I'll come back with a situation report then

Digi7ech

iTrader: (1)

Hi Tech and welcome even though you've been here a while.

I'm Glendale. Sounds like Bad cats since their glowing and getting ready to burn the car down.

If you've already passed emissions then I'd say just gut them for now and see if it helps anything.

If your going to buy new exhaust then you might want to think about either Racingbeat header or downpipe(won'
t have cat so not emmision legal) or the Bonez/rx7.com downpipe and cat(around $300 and street legal/bolts up).

I just passed emmisions easily with this and it gives a deeper little more quiet tone to the exhaust.

I have an extra custom downpipe and cat which came on my car when I bought it. I'd sell it for really cheap because it was not built correctly. The flange to the manifold angle is slightly off and will slowly pry at the gasket ultimately blowing through it. It has a custom downpipe which eliminates the 2 pre cats then a cat.
I don't know about the life of the cat but my car ran fine with it.

I actually think my Bonez Downpipe restricts the exhaust a little more than the older pipe did.

TechSmurf

Just thought I'd give this thread some kind of conclusion.. finally got back to working on the car and did a compression check.. rear rotor seems to be hosed. Zilch across all 3 rotor faces. Is there any way to do a rough check of the condition of the apex seals without pulling the motor.. i.e. feeling them through the exhaust port? Wondering if this would make good territory for an attempt at the atf trick.. though I doubt it, it could be worth the quart or two of atf. Otherwise, may she rest in peace till I find another 13b...

andrew lohaus

i think in a nother thread it was concluded that extreamly hot exhausts can be attributed to the timing being out of wack which causes the fuel to light only once its already on its way out the exhaust. something to check. could be a cheap fix, probobly help the starting too.

poor_red_neck

yeah, take the header off and you can see the tips of the seals (or what is *not* left of them) straight through the exaust port.

Wicked_razor

i dont know how easy it would be to see in there or not or feel for that matter with the exaust inserts in there, i dont know how easy they come out...how long has the car been sitting, has it been garaged or outside? if its been sitting for quite a long time before you got it it could be stuck apex seals