14 replies to this topic

[MikeStewart]

Hi,

I have a 1991 SPi Cooper, I have noticed that there are two vacuum connections at the back of the throttle body.
One goes to the thermal valve on the air filter however I cant find where the other one connects to, currently
this is open allowing air in to the body of the throttle below the throttle plate.

Anyone know if this should be blanked off or connected to something as I cant find anything obvious.


Mike S.

[coyttl]

Hi,

I have a 1991 SPi Cooper, I have noticed that there are two vacuum connections at the back of the throttle body.
One goes to the thermal valve on the air filter however I cant find where the other one connects to, currently
this is open allowing air in to the body of the throttle below the throttle plate.

Anyone know if this should be blanked off or connected to something as I cant find anything obvious.


Mike S.

I may be mistaken, and I'm sure others will say so, but the other one goes to the fuel trap (held to the left (facing engine) and under the air filter housing) and then a hose from that goes to your ECU..

[DaveRob]

As above.... this goes to the black oil trap to the left side of the TB.... from their it goes to the bottom of the ECU where their is a connectoin for your MAP sensor....... without this connection you will have all sorts of fueling issues.... ... make sure all the elbows you fit are good condition... they are prone to cracking .... If you dont have the tube get some Samco vacumme tubing and replace the lot.

Rob

[MikeStewart]

Hi,

I have a 1991 SPi Cooper, I have noticed that there are two vacuum connections at the back of the throttle body.
One goes to the thermal valve on the air filter however I cant find where the other one connects to, currently
this is open allowing air in to the body of the throttle below the throttle plate.

Anyone know if this should be blanked off or connected to something as I cant find anything obvious.


Mike S.

I may be mistaken, and I'm sure others will say so, but the other one goes to the fuel trap (held to the left (facing engine) and under the air filter housing) and then a hose from that goes to your ECU..

Couldnt find the fuel trap but did find the hose from the MEMS unit, must have come adrift at some point. Connected it up to the throttle body and the misfire, black smoke etc. all went away, now running well again. So I'll have to get a fuel trap ordered up and connect it back together properly.

Thanks,
Mike S.

[coyttl]

Couldnt find the fuel trap but did find the hose from the MEMS unit, must have come adrift at some point. Connected it up to the throttle body and the misfire, black smoke etc. all went away, now running well again. So I'll have to get a fuel trap ordered up and connect it back together properly.
Thanks,
Mike S.

I don't have a picture handy - perhaps someone else does? - the fuel trap is mounted on the firewall behind and to the driver's-right of the engine. There should be a little mount with two tabs on either side, and a tab on top, perhaps 2 inches (~50mm) wide - it's small. And yes, not having it connected makes the engine run very rich. - that was the issue I was having last year.

My gut instinct says to be careful driving it without a fuel/oil trap, as if your ECU gets a lot of it in there, it could damage it. But, I'm not 100% on that, so..

[gordioda]

as above about being careful driving it like that for now, im not sure how much/if it will damage the ecu, but even with the fuel trap connected you can get fuel blocking the hose where it enters the ecu (im assuming not having fuel trap will speed up this build up)

even with a fuel trap connected i clean this (hole where hose goes into ecu) out occasionally, i use a bit of rolled up tissue, a lot of people will say leave it on a radiator overnight and the nastiness kinda oozes out but i've never had time to try this

[coyttl]

as above about being careful driving it like that for now, im not sure how much/if it will damage the ecu, but even with the fuel trap connected you can get fuel blocking the hose where it enters the ecu (im assuming not having fuel trap will speed up this build up)

even with a fuel trap connected i clean this (hole where hose goes into ecu) out occasionally, i use a bit of rolled up tissue, a lot of people will say leave it on a radiator overnight and the nastiness kinda oozes out but i've never had time to try this

I've honestly never cleaned mine - I think that's on my to-do list. Other than a connector breaking, I haven't had a problem with these (two) hoses, so I'm curious as to how much 'gunk' I will have in there.. hmm..

[gordioda]

i didnt think i had a lot when i first did it, but i suppose its relative to how big the hole is so it could have been loads
i cant say if it made a lot of difference as i've had a blowing exaust forever

[nipper167]

its most likly to block up on the injection mount (fuel manifold ) side as the filter will keep the ecu side clean

[coyttl]

its most likly to block up on the injection mount (fuel manifold ) side as the filter will keep the ecu side clean

Ah, good point. It never occured to me, since I've seen posts on how to clean the ECU's sensor, but never anything on cleaning the fuel trap (which would seem to need cleaning more often than the ECU!)

[MikeStewart]

The fuel trap is here and has a green and a black connection, any idea which one goes to the throttle body and MEMS module?

[coyttl]

The fuel trap is here and has a green and a black connection, any idea which one goes to the throttle body and MEMS module?

Green goes to ECU. Black goes to manifold.

.. at least that's how it is on my car. '92 SPi.

[MikeStewart]

The fuel trap is here and has a green and a black connection, any idea which one goes to the throttle body and MEMS module?

Green goes to ECU. Black goes to manifold.

.. at least that's how it is on my car. '92 SPi.

Magic, thanks.

[captain kirk]

when mines running a bit rough i take the fuel trap off leave it on a warm radiator over night, works a treat dont ask me why because i dont know

[coyttl]

when mines running a bit rough i take the fuel trap off leave it on a warm radiator over night, works a treat dont ask me why because i dont know

I'd wager a guess because the fuel evaporates. I may have to try that, see if I notice a difference now.