I have an 88 TII and am trying to clean up a rats nest/emissions removal by the previous owner. He had several UIM nipples uncapped, i have no idea how it was able to run with the vacuum leaks.

Anyway, I have a question about where the secondary injector air bleed. Here is the vacuum diagram i am using...



Here is a pic of my engine..



Which one of the capped lines with arrows do i connect to the secondary injector air bleed on the UIM? And BTW, what is that thing anyway?

 

hey thats a nice diagram you got there, the way i did mine(yesterday and the day before yesterday) with the guide from rotaryres.com, was just to capp the front 3 and all but the OMP nipple off. and i havent had any problems running with those 2 on the back your talking about capped off, but its only had 15 miles on it soo far :\ Lol

 

S4 have no secondary air bleed.

 

I made that diagram using the vacuuum routing diagram in the 88 FSM. It shows a secondary injector air bleed but as Hailers said it doesn't actually exist. Very strange on Mazda's part... Hook up the primary injector bleed but you can stop looking for the secondary one.

Sub-zero start assist injector. Remove it and blank off the hole.

The injector air bleeds are there to improve fuel atomisation, which improves the engine's efficiency across the board. There's no good reason to cap them.

 

gxl90rx7,

Not that Hailers needs back up from me, but I think he's right. Also, I'm not sure the blue notation added to your diagram re the secondary bleed is correct. I think that cannot be a bleed line going down from the throttle body to the LIM.

The closest thing to a "secondary air bleed" that I can find in my 1987 S4 FSM Fuel System section are on pages 4B-73 and -74 which sites and shows, a primary and secondary "air bleed sockets" which are located in the LIM.

Good luck.

 

Like I already said, it's an error on the FSM's diagram. I posted that diagram ages ago, before finding out S4's don't have air bleeds for the secondary innjectors.

 

Mine just has a plug where that diagram shows the secondary air bleed. What's the deal?

 

While you have your manifold off, do yourself a favor and check your pulsation damper. On the right side of your primary fuel rail. Sometimes the screw comes off the diaphram and just rolls around freely under that plastic cap. Could save your car in the long run.