Kugelfischer back to the basics

[Rustyfe]

So I’ve been sorting an A4, 4k and above it pulled really hard, then a run and lost a cylinder.  # 3 appears to have lost fuel.

injector checked and cracks about 450 psi.

canked with fuel line off the delivery valve and no fuel.

plenty of fuel flow.

checked the suction valve and seems to be working as it should.

watched the plunger move up and down

checked th belt for the injection pump everything in order.

only thing I have left to check is system pressure, couldn’t find my fuel pressure gauge.

checked spark plug and wire, working as it should.

followed Jason’s tuning instructions.

looking for ideas, suggestions or just plain comments.

compression test 185 psi, valves set at 0.008”.

Thanks,

Rusty

[dlacey]

Theres a good fault tracing step-by-step guide here:

I wouldn't worry too much about inlet fuel pressure... this pressure is just the pressure required to open the suction valve and fill the little cylinder.... so, especially with a one cylinder problem, your issue is likely related to suction and delivery valves or (worst case) a stuck pump piston.

 

[SydneyTii]

3 hours ago, Rustyfe said:

canked with fuel line off the delivery valve and no fuel.

plenty of fuel flow.

checked the suction valve and seems to be working as it should.

watched the plunger move up and down

Serves you right for having an A4😁

 

so if you loosen the delivery valve itself ever so slightly do you get fuel leak out of the piece that screws into the Kuglefischer head?

How do you know the suction valve works if there is no fuel?

Does the feed into the suction valve chamber in the head have fuel in it, is the gallery clear?

 

Robs write up may give you some clues, good luck!

 

 

 

Edited June 7 by SydneyTii

[bergie33]

I would swap the delivery valve to a different location on the pump and see if the problem moves with it. Then you know you have a faulty valve.

Edited June 7 by bergie33

[Rustyfe]

So thanks to all of you for your insight.

swapped suction valves between 1&3 problem stayed with 3.  Swapped delivery valves and problem moved to 1.

i can now see why some go mad for the A4/.

snappy throttle response and pulls hard in the first three gears.  Didn’t go into 4th or 5th.

i had some spare deliveries so other than some fine tweaking everything good.

thanks again, great group of folks.

enjoy you weekend,

Rusty 

[markmac]

They are fun for sure, especially so with HC pistons, and a 300 cam.  Easier to tune than standard Tii's imo.  The only thing you really have to look out for is worn butterflies/throttle shafts.  They are wear items and wear out.  On used sets after a couple hundred thousand throttle blips, it happens.  The good news is that skilled machine shops and or Weber specialists can do the work - its the same deal really as a sd carb.  Have fun with your A4!

[SydneyTii]

I’d love an A4 my brother in laws was epic, out of curiosity what’s the going price for a set of the throttle bodies and manifold without the pump?

[jerry]

9 hours ago, SydneyTii said:

I’d love an A4 my brother in laws was epic, out of curiosity what’s the going price for a set of the throttle bodies and manifold without the pump?

I was offered $7500 for my set a few years back. I will add that it cost me $1000 to have Harry Beiker rebuild it years earlier. He was retiring at the time.  It cost above $3000 for a worn out system on eBay about 15 years ago if I recall. It did include a turbo KF pump that the PO suggested could be harvested for the fuel cone.