Just got an '87 Turbo with emissions partially removed (downpipe (no cats), air pump gone, AC gone). The car has a bad idle (idles fast and rough, will not idle slow). I'm thinking my first step should be to completely eliminate all the emissions equipment to simplify things, etc. Anyone know of a comprehensive "guide" to emissions equipment removal? Any help with the idling issue would be appreciated as well. So far, I've built a diagnostic code reader, which claims no problems. The fuel/air/emissions system is baffling (I've been away from RX's since my '82 with a 12A around 12 years ago). I have a Haynes manual. Thanks for any help.

 

This is my first time posting here. Does anyone know why it says "exhaust leak" under my screen-name?

 

its just kinda a ranking system. title will change as your post count goes up.

 

You should pull off and cap and/or bypass the following stuff:
Air Control Valve (goofy looking thing on the side/middle of the lower intake manifold)
EGR. Another vavle thingy on the back (firewall) side of the lower intake manifold)
If you don't have AC anymore, pull the BAC off. Its right above the ACV on the upper intake. Make sure you route the collant line dirrectly to the Throttle Body.
Do the Throttle Body Mod. Search for it.
Maybe pull off the couple gizzmos on the top of the upper intake.
Remove all the extra vaccume lines and solinoids. You'll need to keep the Fuel Pressure Regulator solinoid and the Twin Scroll acuator solinoid.

Once you fix all the crap, start by reseting the computer. Set the idle screw and throttle cable so everything is nice and closed. Then set the TPS. If that doesnt work, check the TPS, look for intake leaks and check the turbo inlet duct for cracks.
If all that fails, check the AFM, and the BOV....
hope that helps...

Make sure to cap any extra vacumme nipples you have left.

 

So, if you take all of that off, will the car actually idle correctly as well as have more power? I'm trying for a nice steady idle purr.

Thanks,

 

The most common problem is the thermowax going bad or the TPS being bad, so if you address those two problems (thermowax is removed in TB mod) you should be able to make it work.
The other stuff is just useless stuff that you can remove if you dont have to pass emmisions.
If you still have the A/C you need to leave the BAC on there.

 

Re: its just kinda a ranking system. title will change as your post count goes up.

Cool. Thanks.


Re: info from Dyre:

Thanks for the info. I actually found a leak at the turbo inlet duct (multi-axis 90-degree rubber hose). Does anyone know where I can get one at a reasonable price? The only Mazda price I've gotten so far was around $50. Regarding removal of the many solenoids, etc., what do I use to cap the exposed holes at the ex-mounting locations? Does anyone sell plates to cover the holes, or will I have to make plates? Anyone know of a "guide" to emissions removal, or is this just a figure-it-out-as-you-go thing?

 

New thought. Since my Intake duct is toast and my air-filter is in desperate need of replacement, I was thinking a performance intake kit would make an elegant solution. I've seen K&N Cone-filters on some of the cars on this site, but I can't find a K&N Fuel Injector Performance Kit for the Gen II Turbo. Does anyone know how to do this mod and which filter to use? . . . or maybe another cheap (relatively), custom intake system?

 

you just need to buy an adapter and a element and it should bolt right up

 

Rough idling is indicative of anything from a required minor tune-up to an intake vacuum leak...


-Ted