My 93 R1 with around 38k miles only does 10-8-9 boost and I've been told that it's within Mazda's specs. I have heard that some 94+ cars only do 10-8-9 but I thought all 93s were supposed to do 10-8-10. I'm trying to figure out if there is in fact a problem with my turbo control or if my car is actually running normally. Also, my idle is a bit high at 1k rpm with the idle screw adjusted as low as the rpms will get so I'm thinking maybe there's a vacuum leak somewhere that might also have something to do with second turbo only reaching 9 psi... Any ideas?

 

perhaps one of your hoses is kinked

 

You have a vacuum leak, most likely, or some kind of issue with your idle control system. See the FSM for info, and troubleshooting for the idle system
(too much to list, see section F, and memorize it if you want to work on your own car, and do ANYTHING to it.....)

It could be a popped hose.
Kinked won't cause the high idle and reduced boost.

Two ways to check:
1) Use carb cleaner on a "warm" motor, and see where you spray, that the idle goes down (basically, matches the extra fuel for the extra air getting in).

Watch where you spray, and don't hold me responsible if you set your car on fire (have an extinguisher handy)

2) Ultrasonic leak detector ($200+) found at www.acstore.com
Haven't used it, but it should do the trick. It is on my "to buy" list...

9psi isn't really out of spec. In 3rd gear, you should get 10psi, drop, recover, and then drop. Those who don't drop again (around 6000k) have boost controllers, and NEED a chipped ECU.

Why? home.istar.ca/~dvandit/ecu.htm (may not be active)

Look at the max boost - the ECU reduces it towards redline. I ran my car non-seq, which basically means, no boost control. As soon as 6.5k came around in 3rd gear - WHAMM! Fuel cut....

1k/rpm warmed up car idle isn't in spec. A vac leak will do that.
It could be a vac hose, it could be the lower intake gasket, or the upper/lower gasket, etc...etc...

Have fun!

A.F.

 

i've been told that sometimes boost guages just
vary slightly, you might be getting the right boost,
just maybe your guage is off by alittle bit.
just a guess.

 

I have an A'PEXi gauge and I would think it should be fairly consistent. If the first turbo does hit 10 psi... which is should be right, so i think 9 psi on the 2nd turbo really is 9 psi. At this point I'm thinking I'll just live with it until I get the vacuum hoses done, maybe the problem will just fix itself with new hoses...