Hello again. I've got a 93 fd that has a problem. When the motor is below normal running temp the turbos spool nice and the car runs great. But it seems to die down once I drive it for a couple of minutes. I get barely any boost although I do still have compression ( thank god ). I don't have the typical sighns of blown apex seals or falure of the rotor houseing. I am baffled. This leads me to believe that it has something to do with the turbos but what? It runs fine at the start. With nothing found by the ecu how the heck am I supposed to fix it. One theory I do have is that I do live in upstate ny and we have been getting some record breaking heat this summer. And if u know rotory than u know heat is like cryptonite to these motors. Can this be it? I'm just rambling on....... Simply put HELP!!!!

 

Check the Double Throttle Control actuator and the vacuum lines that operate it. There are only a few control items that operate off temp and this is a major one. This shuts off the air flow to both secondary runners. It is supposed to do this when it is cold and open at normal temps.

 

Is that the turbo control acutuator? If not I'm having trouble finding it. Can u let me know the general location? Thanks

 

It's at the throttle body. Most people just delete the secdon butterfly. If I'm correct

 

This diaphragm with the nipple and linkage assembly

 

Ok. Found it. Now how do can I tell if it's actualy the DTC actuator?

 

If the DTC is not working I mean. Sorry I needed to explain the last reply

 

Actuator rod out (like the picture) is butterflies open.

So, first thing you need to check is the position when it is cold. Cold the rod is in, butterflies closed.

To test it, temporarily disconnect the vacuum hose and plug it. Take the car for a ride see if the problem persists.

 

WOW what a difference. Perfect diagnostic. I unhooked the hose and plugged it then I'd say I went for a 15 minute drive. Worked perfect every time. So now can I permanently plus the hose or should I replace the part?

 

You can just leave it disabled, just remember not to go full throttle on the car when it's cold.

Dale

 

It is the solenoid that controls it that is the issue. If you feel like replacing it you can. However, depending on the condition of your vacuum lines, check valves, solenoids and engine harness you might be opening up an expensive can of worms. If this is the only problem that the car was having then just leave it disabled until you feel like doing a vacuum line replacement or simplification. A simplification would eliminate the double throttle completely.

 

I will eventually do a replacement of the lines but not now that's a off season project. Not only did this fix my cars overall performance I also had issues at start up because sometimes my car would rev high then stall. Now it just starts and idles perfectly. I would like to thank all. This forum is kick *** for real. Thanks

 

Well I think I opened an expensive can of worms. The car sometimes bogs heavy only when in low rpm in gear. It also started to stall again on cold start. And the worst thing is that the oil pressure doesn't get above 30 when I drive it at high rpm. Still no smoke thank god. I think it's a vacuum line but I'm no rotor genius. What do u guys think?

 

Oil pressure is probably just the sending unit, the fail all the time. Unless you are reading this from an aftermarket gauge, then you have a major problem.

Sounds like you need to get your car to a shop or start that winter project a little early.

 

Assume worst case. I know u can't diagnose for sure without looking at it ur self but humor me. I don't have an oil leak there is no black or white heavy smoke coming from the exaust. I can hear the turbos spool fine. If it's not the gauge then what can it be? I'm hoping for the best expecting the worst. I just want to be prepared u know

 

Humoring you.....the worst case senario it is the front cover o-ring blowing oil back into the engine.... or a worn oil pump.... or a faulty oil pressure regulator. All of which require major work. However, chances are it is just the sending unit as I previously said and I would not get too worked up about it without changing the sending unit first.

 

^^^
Agreed. Mine went bad at ~40K miles. Read erratically (very low). I looked for other possibilities, but it was the sender.

 

Ok. It's hard not to get worked up though. Problem after problem. If it was any other car it would have been in the scrap yard, I just love these damn cars.

First things first. The sending unit is located where? And how much do u think for a new one. Honestly I couldn't wait till winter to do the hose replacement project so I just dumped over a buck and half on hoses and misc tools. If u could snap another picture because the one u took of the double throttle control actuator helped me emencely

 

No pics, but the sender is just below the oil filter. One wire, and it usually has a rubber/plastic boot over it.

 

I took my car to work yesterday and on my way home a check engine popped on the dash. I'm going to get it diagnosed today. When I do I will pos the code on a new thread. I wan to fix the problem myself for 2 reasons 1). It gets me in the garage away from the wife and kids for a couple of hours. 2). I don't know if u guys know the difference between a mechanic and a tech but going to see a tech that has experience on these cars is a long drive for me. I hate going to a Mazda dealer because they r all mechanics. Ex. Say I have a blown apex seal. Instead of a motor tear down to replace it they will just say that I need a new motor. Techs fix, mechs replace u know

 

All you need is a paper clip to pull the codes

http://www.banzai-racing.com/FD_S5_error_codes.htm

 

I went and got a diagnostic on the car. Only code it showed was the engine coolant temp sensor that's it. I'm ordering that and a new sending unit for the oil pressure problem to see if it cures it. On the side not of no check engine my speedometer and my tack needles go crazy sometimes and a check engine comes on then it seems to be fine and the check engine turns off. I thought that it was some sort of speed sensor but it didn't show on the diagnostic read out. Could it be the cluster itself? Everything else works fine ( besides oil pressure).

 

What happens to/ with the DTC if it's not vac'ed in, at all (i.e.: Full reduction)? What problem(s) can this cause?

The DTC is on the backside of the UIM and is the highest thing (vertically) that has a vac line runing to it... Well SHOULD have one, anyway.

 

If you did a vacuum line simplification, then it should be removed and blocked off. It really will do nothing without a vacuum line, as I already said, the default is open.

Block off plate kit http://banzai-racing.com/store/FD_block_off_plates.html