I have two questions:

1) I read somewhere that having the wastegate control and turbo precontrol switched (at least I think those are the two) can cause a low 7psi boost on the secondary turbo. I had a mazda mechanic tell me they were reversed and fix them a while ago, but its very possible something else happened to reverse them again (maybe another mazda mechanic). The two solenoids I'm talking about are the ones bolted to the front of the UIM. Since I'm getting similar boost patterns and can't find any other source to the problem, I thought I'd try switching the two just to see if they are reversed. In any case, is it safe for me to switch them just to see what happens? Or could that result in damage?

2) If it is safe to try switching them, then what is actually meant by "switching"? Is it the top two vacuum hoses, all the vacuum hoses, or maybe the electrical connectors?

Thanks

 

the wastegate and precontrol actuators are bolted to the casting on the primary turbo. I'm confused

 

just reverse the electrical connectors to the solenoid. That is most likely what has been swichted. Be careful as you may get a LOT more boost than expected.

 

he is refering to the selonoids, labeled I and J on the vacum diagrams, not the actuators.
i just swithched the elictrical connectors when i thought i had them cross. this didnt cause any problems, nor did it fix the one i had.

 

yes, it limits boost. i have them switched right now while waiting on a boost controller. i can run a perfect 7psi all day long, and still hang with many-a-car......

 

Try switching the elect connectors , there should be a white dot on one solinoid and one connector they go together

 

Switch the electrical connectors. There should be a white paint dot on one of the solenoids and one of the connectors, but it can wear off after a while. If they are wrong, you get 7psi and if they are right you get normal boost, so I don't see any danger in switching them.

-Max

 

I had a chance to try switching the two electrical connectors, and although it fixed one symptom (no more loud whistle above 4500rpm) it resulted in lower boost from the secondary than I was already getting so wasn't the original problem.

My boost pattern with the connectors on correctly is something like 10.9-8-8.9, with the wires switched it was 10.9-8-6.2 which is about what would be expected when connected incorrectly. I have to admit I briefly considered just leaving the wires reversed because it is so much more pleasant to drive without the whistle. I'd never be happy that way though.

So anybody have any ideas what else could be wrong? I've checked all the hoses I can find, including under the UIM, everything looks good to me. I'm starting to worry that there is something wrong with the turbo since everything else appears to be in order.

 

well, where are these electrical connctors? Where do I look?

 

they are between the airpump and the uim. They're mount on the UIM with 4 bolts...

 

i have the whistle too..anyone??

 

I discovered the connectors switched on my car a few months after I bought it and after installed a boost gauge. The dealer did it when the previous owner has it worked on. You might want to check the hose with the "restrictor pill" in it. If the boost control hose is real hard and old then pressure could bypass around the restrictor pill which will reduce boost. Check out robinettes website on boost control for details.

 

Could this be my non seq boost problem?