ColinB

Not so Bob
See Hilton's first pic. It comes off the underside of the throttle body.

Colin. 89GT.

the flyin' scotsman

Its interesting that there's a difference on vacuum ports on the throttle body between auto/5 speeds/RH drive and LH drive cars.

I clearly recall my own intake R&R this past winter as well as Adrians who was doing same at the time. Both our cars are '88 autos but his being RH drive in the UK and my car being LH drive in Canada. The pics of Adrians tbody and my own were identical; 2 ports on the topside, one for fuel system/trans the other for the charcoal canister; one port on the bottom side for the air diverter from the air pump to air filter or cats.

Hilton

Dr bob, that photo'd cap is indeed a vaccum line - white plastic vacuum line; the same one in my first post.

Jon and I also have the factory test ports. Our cars are both UK RHD non-cat 5-speed cars. The cap on the exhaust test port is hard grey plastic rather than red rubber.

Oddly, the thread Paul (ukkid) linked to shows his throttle body ('87 MY) has 2 vacuum connections on the underside, compared to a single one on mine.

Hilton

Ah interesting, sounds like the RHD auto's match the diagram in the WSM. I'm guessing Paul's throttle body with two ports was to allow for manufacturing autos with the vac test port too.

the flyin' scotsman

As your cars are non cat do have have an air pump and all the plumbing? Where is the charcoal cannister on a RHD car?

I suspect what your reffering to as a vac test port is actualy the vac line for the air diverter which you dont need or have in a non-cat car.

jon928se

RHDs non cat have the in the air pump usual place but the air is injected into the underside of the exhaust ports in the heads right next to the exhaust manifold connections. These holes have threaded bungs in them in Cat cars two of which are used for the exhaust gas temp sensors.

The charcaol canister is in the normal place.

The Vac test port is a vac test port. The vac line for the diverter valve is separate and connects to the 4 port Tee.

ColinB

Jon
I've never looked closely in that area, (and I'm a long way from the car right now) but I don't think I have any air injection piping beneath the exhaust ports. What size piping do you have and what purpose does the air injection serve on a non-cat car? My air pump is disabled (belt off) but the car runs perfectly.

Colin. 89GT.

UKKid35

You can see the hex headed blanking plugs in this pic. The purpose of the air injection is to reduce emissions by burning combustion products more fully (less CO more CO2 etc).

jon928se

Hi Colin

It's all but invisible from above - infact I don't actually think you can really see any of it. Even from underneath it isn't blindingly obvious until you go searching for it.

If your 89GT is originally a non cat car it is always possible it has been removed prior to your ownership ?

Mrmerlin

XLOT it looks like your ride is a prime candidate for some new fuel lines there are 4 of them since you doing other things nows the time to fix these

ColinB

Thanks Paul. So having no air injection wouldn't affect performance then, just emissions?

Hi Jon. As far as I can tell my car had no cats when it left the factory. They weren't required here in '89. For example it has the open loop ECU. But since it has the air pump I suppose the pipework must be in there. I'll need to take a closer look.

Nice new avatar Mr Merlin. Now, let me see, didn't some Mustangs have a RR Merlin engine?

Colin. 89GT.

jon928se

No that's my ride ! and yes you are correct it is a prime candidate for new fuel lines. Xlots' 89 has all new fuel lines.

westside oz

Hallelujah this thread has answered the same question for me. Driving me nuts. One more thing ticked off The List.