Audi 100 Won't Start: Removal of Injectorq

[Ben Swann]

Mark - that is great progress in that you have shown no fuel coming out of the injectors ports!

My experience on this as I mentioned earlier, was to thoroughly clean the DPR and orifices in the metering head.  Sometimes you need to do this several times, and running the pump to purge fuel through can help expel crap too, try to catch in a rag or container and of course be careful with the gas.

Following that you may need to take the distributor head off.  I think you have enough access to everything first, by removing fuel injector lines individually and getting the gumout in all the orfices you can find.  If/when you take the metering head off the airbox, be most careful with the plunger as if damaged you can write everything off as they are matched individually to the metering head.  Removing the plunger will provide access to thoroughly clean everything.

You may have clogging around the plunger, if you can access underneeath spray enough in to work it loose.  I don't think so however, as that would mean all of the slits in the metering head would be clogged.

So I'm not advocating taking all apart as I explain above, unless you are fairly certain the fuel was old and pretty much turned to varnish.  In this case, you should have completely drained and purged the tank and be starting with new fuel - injector cleaner in there would hasten the cleaning.  If you think about it, there really isn't much to break on these, only bad fuel can clog and/or water may rust components - I have really never seen this, perhaps someone else has.

Again, the most recent time I recall having this problem - that is when air plate lifted, no fuel came out of the injectors - a thorough cleaning of the DPR was the fix.  This means getting the little kit from the dealer with O-rings and crush washers, which should be used on reassembly.  I don't beleive the DPR can be easily disassembled, but again cleaning can be done by shooting gumout or other through the orfices on both DPR and distributor - spray in one and spray comes out the other - watch those eyes!

Ben
p.s. I have at least one extra metering head if you need one.

[snipped disertation on fuel not coming out injector holes when sensor plate is lifted]