Mi16 Throttle Body Butterfly Failure

[VisaGTi16v 1]

Strange one this. The Mi16 lump in my Visa sprint car has been idling high for the last few hundred miles. I thought it was probably a breather issue or something like that so I had a quick poke around in the engine bay yesterday. I noted that the throttle linkage on the throttle body had about 1cm slack in it each direction if I moved it by hand and you could pull it in and out! I had a look at my spare throttle body and couldn't work out how this was even possible.

 

So after noting this slack yesterday, I had a closer look today and started unbolting things.

 

Reason is shown below! One of the screws had come out and then that bar across the middle snapped due to the stress on it. Due to this other retaining bit on the outside, the throttle linkage couldn't have fallen off but the other screw may have failed after a while.

 

Of course, the screw was from the inside and so it went engine direction! In a moment of sheer brilliance and using a bit of cloth cable tied around the end of my trolley jack handle (!!!) I managed to shove that into the inlet manifold, fish around a bit and drag the screw out.

 

I fitted my spare TB and it all seems fine. I only ran it for a few minutes but it seemed to be idling lower. Perhaps the air hole on closed throttle was annoying it, maybe not but either way I am glad I found this problem before the screw bounced up and had a meeting with the valves!!!

[Baz 421]

My old Mi was like this, with a screw missing and the spindle broken, think it was like it when i bought it, but i never did find that screw though!!

 

Could've been nasty!!

[James_m 0]

How did the screw not get ingested before hand then? was it just sitting around in the inlet manifold for all that time?

Pretty worrying, would be a bit of an unfortunate way to lose an engine!

[VisaGTi16v 1]

No idea James! If that hole where the screw was is the cause of my high idle then its been in the inlet manifold for a few hundred miles and one sprint at Debden!! Need to go out and bed some pads in one night so will see if its back to normal then which will confirm what I just said and also how lucky I am!

[Sandy 191]

Bloody lucky!

[maxi 36 1 Cars]

This is a common problem that happens all the time with mi's! My old engine sucked in a screw and f***ed a valve and a piston. I did post a few years back on this forum saying all converted people should check their TB's and if in doubt loctite them in.

 

Baz, your miami mi inducted a screw when my mate Luke owned it. It has had several different engines and heads since then though so I should think it must have done it again.

 

Maxi