UR Quattro 20v Injectors

[predding]

Hello, I have the above with ABY engine (I think). Apologies for what is probably a very simple question but, having been pretty ill these past 2 years, car has been standing and was last used with E10 fuel on board. On start up, engine is hunting on idle and whilst running on 5 cylinders is v rich on idle and under accelleration is gasping and misfiring. Everything points to the injectors being gunged up and/or the fuel press regulator diaphragm is leaking. I have all the tools to clean them now and replace BUT simple question - after 32 years, how easy is it to pull the injectors out as the joints may be heat hardened etc. Basically any tips appreciated as I have lost a shed load of confidence...Kind Regards

[B5NUT]

I removed my ABY injectors without any issue. Give them a bit of penetrating fluid a day or so before you remove them as it should help a bit.

[newsh]

Remove the two bolts holding the fuel rail and pull the rail upwards with the injectors attached working one end then the other, should come out complete. Fit all new O rings ?

[predding]

Thats great guys - thanks so much on the tips on the pen fluid and removing the whole rail assembly as had been wondering if that was the way to go. Really appreciated. Cheers

[K Simmonds]

Remove the two bolts holding the fuel rail and pull the rail upwards with the injectors attached working one end then the other, should come out complete. Fit all new O rings ?

This is the correct way of doing it, with bit of a wobble it should come free quite easily and lift away from the engine.

Before removal blow the area surrounding them off with an airline to prevent crap from falling into the engine, if you don't have a compressor then a hoover will do.

I would replace all the O-Rings and give them all a light smear with proper red rubber grease, this will ensure they all seat properly when being refitted as well as making the job a good deal easier.

Also while your at it check the condition of the pink inserts in the plugs to the injectors, these are often failing to bits after 30 odd years. The ones on my 1990 3B where brittle as hell ten years ago and were causing connection issues.

The pink inserts are a generic part used on a lot of VAG cars from the 1990's so are still available or at least they were last year...

If not I can probably find you five inserts, I scrapped two complete looms today and cut all the connectors and boots off first.

[newsh]

I came back to mention the pink connector inserts but you've done it Kit, well done. Had to change them all on my 3B, easy enough.

[predding]

Thanks so much K Simmonds and newsh; the garage was alot warmer this morning so bit the bullet and gave it a go. It was easier to remove the clips holding the fuel rail to the injectors as the injectors were stuck fast in the head. With some very careful easing it lifted off but it wasnt without alot of trepidation, not least the two Allen bolts holding the rail on as they hadnt been undone since leaving the factory so I made sure the key was a really tight fit. . Then getting the injectors out, I needed to fabricate a forked lever to ease them up as I pulled and even then it took a heck of a lot of pulling. As you said, there is a lot of debris around the holes, I will plug them and clean the area carefully. I will check the pink inserts too and lubricate the rings on re-assembly as I got full seal sets from Audi Tradition. Next job is to clean them all with an ultrasonic and purge them through with the pulse tester I bought. Is injector cleaner the best fluid to use to clean them out? Cheers

[Tractor Dave]

Best way to clean injectors is to find someone local who has an injector cleaner machine. This will properly purge and flow test each one. New o rings and gauze filters also recommended. You can't just flush as they need voltage to open up.

[predding]

Thanks Tractor Dave; I bought one of these testers to activate while purging with the aerosol cleaning fluid https://www.amazon.fr/dp/B01CNPKN1K?...roduct_details Thanks for the note on the filters too as I wasnt sure if this type was fitted with them. I will continue tomorrow and report back. Its all probably pretty standard work for you guys but its a journey into the unknown for me so appreciate all your helps

[predding]

Do the injector micro filters really come out as mine are well and truly stuck in despite inserting a screw and pulling, Is there any knack to it? And if they do come out, is there a part number or size for them? Thanks

[predding]

Small update: I have all the injectors out and just waiting for the micro filter extractor and new filters to start the clean and test. In the interim, what would be the best way to fettle the square injector rail ie remove the rust and treat. The original factory finish is a very smooth silver / aluminium finish. I assume the tube is steel?

[predding]

Back again. All the injectors have now been cleaned (purged) and tested and giving a good spray pattern - it took a good 2-3 seconds on 4x of them to clean and the fifth nearly 10 seconds continues purging. I went through about a half can of carb cleaner in the process

I am now refitting the injectors; installing into the head / manifold has been a press fit but the injector rail onto the injectors needs quite a force ie none are pushing over the new O rings. I have lightly smeared them with grease keeping clear of the injectors but it seems to need a hck of a force which doesnt feel right.

Is there a trick to it?

When I get to the restart, should I get a good 5-10 litres of fresh 98 E5 in the tank (in cans) as it is about 1/4 full of old fuel and / or add fuel injector cleaner too to clean the residual out of the fuel lines?

[newsh]

Is there corrosion in the fuel rail, you might need to polish the inside with Scotchbright and metal polish so they slip in easier. I ended up using a later fuel rail from an AAN or ABY which are stainless.
I'd siphon the old fuel out and put in some fresh 98. Use the old stuff up a few litres at a time or in the lawn mower.

[predding]

Thanks newsh - there is some roughness / dirt inside the rail cups and you can see the shiny parts where the old O rings sat so will get to work on it and polish them. I am also going to fit all the injectors into the rail first using some kind of press tool then fit the assy into the head (the injectors seem to push into the head quite easily - what is bizarre is when you look down inside, the hole/seat is actually shaped in 6 sides yet the O ring and cap that faces onto it is round . I took a load of pics before removing so can see how many rings on the injector body show when it is fully seated. Will look into draining down the old fuel too.

After all this I will be taking a heck of a lot more care how I store the cars over winter!

[newsh]

I use a blue waterproof grease on the rings or plumbers silicon grease works too, nice and slippy.
The hex is for the big Allen key for removing the plastic injector seat from the manifold, the part where the O ring actually seals is round. Don't try and remove them unless they leak though, they will probably come out in pieces. BTDT