I believe your EGT's get lower if your engine is running rich, when you run lean your EGT"s go up.

 

Yup that's exactly how it moved. It seems OK, I just have to get the damn thing back on now, which is a PIA because it seems impossible to get on there with that hose that connects the bottom of the BAC to the intake duct. Is that hose supposed to be hard? It seems like it may have been pliable at one point but now mine might as well be a solid piece of plastic.

 

OK well I don't think it's the BAC. I took it out, let it sit with injection cleaner in it, drained it out the next day and wiped it down, exercised the valve (the accordion moved just like you said - 1/4 inch) and threw it back on with a new piece of hose and hose clamps to attach it securely to the intake duct. No change in anything.

I also noticed something bad. My coils were sparking. Now, they had been doing that before, only then there were little sparks jumping up and down the whole length of the plug wires. So I replaced the plug wires and no more sparking anywhere, until tonight - this time just at the junction of the plug wire and the coils. Both leading and trailing. I find that pretty freakin strange. Anyways I replaced both coil packs and no more spark but also no change in my problems. The only thing left to change there is my plugs. What a bitch.

 

Loosen your throttle cable linkage to get your idle down?

 

Changed my plugs. Engine is stronger than **** now but still doing it's fricken bounce thing.

As for the throttle cable, I suppose I could try that but I highly doubt that has anything to do with it. If it was tight, for instance, it should hold steady at a certain RPM, which it doesn't do.

I do find it sort of interesting though, that if I try to hold the RPM's at say 2000, then they still bounce, but they bounce less. So like, at closed throttle, I get a bounce of 1300-1600. Trying to hold it at 2000, I get a bounce of more like 1950-2050. Shortly above that it disappears entirely.

This is probably going to end up being an intake leak. Son of a bitch. I still have to try the water thermo sensor. Who knows, maybe I'll get lucky.

In any case I'm learning a hell of a lot about this damn emissions set up.

 

OK change of pace. This is one of the first things I should have checked of course, but I didn't. Anyway, I just found a crack in the inlet hose to the turbo. it's about 1 inch long and it begins at the end where the turbo is. Doesn't look like it would let a lot of air in but obviously it needs fixing. Also the hose clamp that holds it on doesn't even look like it can really grip the thing very well, so that might be compounding the issue.

Questions:

1) Is duct tape securely applied before I get this part new a really bad idea?

2) Is Mazdaformace the cheapest place to get this part?

PS I unplugged the water thermo sensor and no change, though the cold startup at 3k for 17 seconds appeared to happen with greater gusto. So I don't think that sensor is my problem.

 

Argh. I jury rigged that crack shut with electrical tape and my problem is totally unchanged. I guess it wasn't letting much air in. Son of a beyotch. Back to square 1, again. Stupid stupid stupid.

 

bump

 

Fixed my idle, there were acorns holding the secondary throttle plates open. I'm psyched.

Still need a TID though. Don't know if I should try making one of my own... now that I have it fixed I want it running right away.. I covered that crack temporarily in electrical tape.. no danger of tape getting sucked in the way I did it, but I'm not sure if it might melt if I get the car really hot.

 

You are correct that the _engine-out_ exhaust temperatures will be lower when an engine is running rich than when it's running less rich (technically, most spark engines never run leaner than 14.6:1). But the extra fuel in the exhaust burns in the catalyst when it combines with air from your air pump. So the catalyst temp is higher (with a working air pump) when you run richer.

Sorry for the off-topic comment, just had to clarify.


And for something on-topic: I had the same high and bouncing idle problem, and it turned out that my throttle cable was too tight. Now it only bounces when it's half way warmed up. Apparently, if the TPS tells the ECU your throttle is closed, and the ECU thinks the car is warmed up, the ECU limits engine RPM to 1500, and cuts fuel if they go higher. So for some reason my ECU thinks the car is warmed up before my thermal wax does...

edit: or maybe I haven't readjusted my TPS since I fixed the tight throttle... Maybe the ECU only looks at the TPS position (which should be slightly open until the thermal wax allows it to close). That would explain the behavior I'm seeing.

Sorry for the slight thread hijack to explain my epiphany!

 

My bouncing idle ended up being caused by a tiny amount of acorn shells which had been mashed against the outside of the throttle body where the stopper for the throttle plates rests when the throttle is closed. So the throttle was being held ever so slightly open by bits of acorn. I found this while I was staring blankly at the workings of the TB.. I looked down into that little space there and I was like, wait a F'n second.. stuck a screwdriver in there and scraped out like 1/32nd of an inch of this crap and saw metal underneath. Threw the intercooler back on and bam, fixed. Unbelievable.