Vapor Lock/Bonehead admissions

Ameer Antar antar at
Tue Aug 13 18:00:36 EDT 2002

yes, i think you're right...that's why Audi decided to put them in there. The injector
cooling fan helps quite a bit, b/c the injectors are in a stifling part of the hood. If
you can' get the injector cooling plenum or don't want to spend the $$$, how about
connecting the large hose to 5 smaller hoses and tie each to an injector. You'll
have to be creative in connecting all the hoses together, but shouldn't be too bad.
There are other problems that cause hard starts: fuel pump check valve, leaky
injector or fuel component, fuel damper, etc. Start w/ the easy stuff (like putting
on the injector line boot..) and then move on to the expensive stuff if there's still a
problem. Good luck.


---Original Message---
>Message: 10
>From: "Mark Woodland" <markwoodland at>
>To: quattro at
>Subject: Vapor Lock/Bonehead admissions
>Date: Tue, 13 Aug 2002 11:14:32 -0400
>Hello listers
>After replacing the fuel distributor and injectors on Max ('87 5KTQ), I
>didn't replace the rubber boot over the injector lines, or the injector
>cooling fan's hose(ripped) and injector air diffuser plenum (cracked/broken/
>disintegrated on removal).
>All was well until June, when it began no-start conditions when hot. Between
>battery ailments (it was in the process of dying)and home/work demands, I
>just shelved the whole issue, putting only the odd hour or so into diagnosis
>every week or so.
>After replacing the battery, and getting it  ready for state inspection.
>its finally dawning on me that its probably vapor locking, as it has always
>started from cold, and always failed after being warmed up, then shut off
>for ten minutes.
>1. Does the rubber injector line boot need to be refitted?
>2. Does the vapor lock diagnosis sound plausable?
>(Anybody out there have a decent used air plenum for the injectors?)
>I just find it hard to believe that the injector cooling fan can bring the
>injector temps down when the block/head temps are so high.
>I suppose that I should know better.. its all there for a reason.
>MSN Photos is the easiest way to share and print your photos:

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