Hi Folks i know its been done to death but my combi turbo has a problem with the metering unit. It seems to have a vacuum leak somewhere which is not pulling down the flap. I can wind it and nothing. if i remove the cone filter and press down it fires up first time.

Silly question but where would the leak be? Is there any prime locations that i can check?

I owned the car many years ago and it wasnt the best starter back then so im needing to get my finger out and actually spend some time tinkering about with it.

Any pointers would be greatly appreciated.

Thanks,

Ryan

 

Throw away the mfi and fit efi.
Or adjust the flap height adjuster that's just behind the cone filter,but since it's a water trap it will be seized.

 

Inbetween the air entrance and the fuel metering head is a tube with 2 screws,inside there's a Allen or flat headed adjustment screw for pushing down or raising up the flap,more than likely seized though so wd40 it to start with.
I'm guessing that it won't start due to no air which says to me the system us airtight as if the flap is closed and sealed then if there was an air leak that would allow air into the intake and the engine would fire,you pushing the flap down is allowing the air in so I'd say try adjusting the screw.
Pretty sure you set the gap between the flap and filter housing with a feeler gauge,maybe have to google the recommended gap?

 

You don't want to see the nick of it lol. I took it apart today and its seized solid with rust

 

Just remembered.
I'm sure the bit you adjust does not have a thread,I'm sure you push down and it engages with a square drive on the flap itself which is threaded so when you release the pressure the part you see pings back up.
It could be a bit of trial and error and I'm sure xr3i's are different so it has to come from a turbo.

 

I will get round it

 

When it starts, does it keep running or stall again?

 

Yes it runs no problem. Once its warmed up the idling becomes a tad erratic.

 

Ok, so we have a classic Bosch KE depression issue. Its like a human depression issue, but easier to fix, although if left... it can also CAUSE human depression too. LOL

First thing to check is crankcase integrity, so we need a good seal on the oil filler cap and the dipstick. Crankshaft mains can cause this too, as can teh distributor seal.

If you have a dump valve, remove and block the pipe immediately as its almost always these.

if none of teh above helps, add 1/8th of a turn clockwise to the metering flap base position adjuster. (NO MORE) and see if that helps.

Also bear in mind Bosch KE requires 25% throttle during cranking. (RTFM)

Bear in mind I am looking at hot start issues, If this is a cold start ONLY only problem it could well be the dreaded failed black box. Testing that is a lot more involved.