hey guys,

I was hoping you could clarify a few things for me. I happen to be running FD Throttle Body and UIM with S5 LIM on my '87 Turbo II. I just need to know some things about the vac nipples for the FD UIM.

I need to know where to connect the Secondary Injector Air Bleeds and the OMP Injector hose. I believe they both need to source filtered air prior to throttle plates, not boost. Are any of the nipples on the UIM drawing from prior to the throttle plates?






Thanks,
NJGB

 

Does anybody know where to hook up the fuel injector air bleeds, both primary and secondary?

I am not worried about the OMP stuff any longer but would like to be able to route the lines for the fuel injectors air bleeds soon. Thanks for your help,
NJGB

 

The OEM primary injector air bleeds on the 93-95 models are fed by the compressor outlet on the primary turbocharger. If you've got an extra nipple between the turbocharger and the intercooler this is where Mazda chose to plumb them and my guess is this has something to do with pressure drop across the intercooler.

If you want to replicate the FC setup, you might be able to use the idle control solenoid blockoff plate. The flange for the OEM idle control solenoid has two halves; one of these halves gets air from before the throttle and the idle control solenoid lets a certain amount of air bypass the throttle. You may be able to tap the pre-throttle side of your idle control solenoid blockoff plate and install a nipple to feed the injector air bleeds.

PS, I'm a nice guy so I won't poke fun at your blockoff plates; if they get the job done and don't leak I suppose that's all they really need to do.

 

From the factory that stuff was hooked to the clusterfuck of intake and intercooler piping, not on the UIM like on the series 4 and 5 manifolds.

There are a couple ways you could plumb it, but one way to do it is to just drill and tap two holes on an intercooler pipe. For one of the holes, tap it 1/8 NPT" and use a 3/16" --> 1/8 NPT barb. Attach your fuel injector bleeds to this using 5/32" hose or 3.5mm (hose will stretch for a tight fit). I don't recall if the FD UIM has secondary air bleeds or not like the s5, but it does have a primary air bleed port.

For the OMP, I think I am using 1/4" (double check that size) fuel line to the big part of the 4-way splitter. So after verifying the size of the hose you need, tap the intercooler piping either 1/8 NPT or 1/4 NPT and get a brass fitting with the correct thread and the appropriate barb size. I use 5/32" or 3.5mm hose from the splitter to the four oil injectors.

 

Thanks for the information fellas, I do appreciate it. I just took the car out for the first time in a few months with them blocked off and it seems fine but I will hook em up like you said.