[urq] Injectors out under boost?

DGraber460@aol.com DGraber460 at aol.com
Mon Oct 3 15:09:54 EDT 2005

In a message dated 10/3/2005 7:58:13 A.M. Mountain Daylight Time,  
fdekat at sentex.net writes:

HAs  anyone ever had a CIS injector sort of 'come loose' under boost?

I'm  trying to sout out a 'miss' under boost. After a long pull under boost
(Say  a big hill), I get a condition where the motor sounds sort of like a
miss,  and I can smell  LOTS of fuel. The sound when this 'miss' happens  is
sort of like a long running mellow fart, for lack of any better  explantion..!

The plastic 'shround' that is supposed to cool the  injuctors is 'sort of' in
place, but since it's been broken (aren't that  all?), I'm not sure it's doing
an effective job of holding in the  injectors..

My theory is that an injector may be coming out just enough  to let boost air
(and fuel) out past the injector. THat would explain the  miss, and the fuel
smell.  Repeated attempts at full throttle then can  provoke the miss with ANY
boost (as I figure the injector still could be  loose)

After letting off for a bit, the vacuum in the intake pulls the  injector back
in, and things are good again.

So, if anyone has had  an injector come out, what were the symptoms? Similar
at all?

(A  further detail: the MC motor has the original WX 'non shrouded'  injectors
in it. Maybe a case of them not matching the MC's head shrouded  injector
holders correctly?)

And second, does my theory even make  sense?

( I was thinking of testing my theory by removing the plastic  injector
shround completely, and seeing if an injector pops right out. But  the thought
of fuel spraying everywhere on the hot motor if an injector  pops out makes me
think that's not such a good idea!  Maybe just  replacing the injector  o


The injector seals should hold the injectors in unless you have increased  
boost a bit. There is a cam cover trim on older 5ks that has an injector  
securing function you might try to source, but I believe those injectors have a  
different profile on the joint, and it might not fit.
I'm running 16-18 PSI and never had one come out. Then again I have the new  
green seals in place.
I'd go for the new green seals. They are awfully tight.


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