Hi just wondering if anyone knew if there should be a type of cap or cover that should be on the tube that holds the mixture screw on the xr3i fuel metering unit?
Would it have had one when the car was first made at the factory?

Reason I ask is because there is a high pitched whistle coming from that tube on mine and goes away when I put my thumb on it.
I know these MFI''s such as mine are a bugger for vacuum leaks you see.

Whenever I see photos of other people's engines they never have a cap on but this just seems odd to me.

Anyone??

 

It is, in essence an air leak yes. And they should be capped. However its a rarely seen sight, and most people leave them open as per the pic

 

Oh right OK so it should be causing me any start up or running problems?

 

There wasn't a cap on K-Jetronic metering units as the (3mm inhex) screw inside is used to set the mixture.

There WAS a cap on KE-Jetronic engines (90 bhp, catalyst, this metering unit with the blue electronic/hydraulic unit like ERST units also have) because trying to adjust the mixture with the screw won't be good.


Vacuum leaks on K-Jetronic engines is a problem. But only between the flap in the metering unit and the cylinder head. The pipe sits outside, so it won't affect air/fuel ratio.

 

Thanks for that I didn't know it was different from the k jet to the ke jet.