Stock Coils Resistance Info!

[FabS6]

I can't tell you much more at this point. What I can say is, I would suspect either the POS for cylinders 4 or 5 (again, try a good used (borrowed) brown V6 "351" POS to see if the problem goes away) AND/OR suspect the wiring to coil 5 (it would have been twisted when you lifted the coil pack and laid it on the cam cover when you removed the spark plugs. MIght have broken a wire and/or insulation. Other than that, Plug No. 5 could have an issue or the coil to plug connector boot. Find those "old" ones and replace at least No. 5's.

I understand mate...I"ll try to find out if it is exactly the #5 that is causing the problem/headache to me! About the brown 350 POS...I don't know anybody with a gasoline Audi V6 here so I'm forced to buy it unfortunately Anyway, I will follow your instructions tomorrow morning as a must!!! I appreciate and thank you for all the support you are giving me mate!

[UrS4boy]

I was only suggesting the brown V6 "351" POS because where I am, you can typically find them in autowrecking yards for cheap money. I understand the situation might be different in Italy, especially with the large number of diesel powered vehicles including C4 Audis. Try to determine whether it is No. 5 and then try swapping the pairs of POS connectors and see if the miss moves to No. 2 instead. If it does, you can swap the pairs of the connectors back to the way they were and then go after using the spare channel on the 4-5 POS to trigger the No. 5 coil properly.

And BTW, they do just go, or at least get flaky, for no reason. One day fine, the next day, problems. So your July to Oct. car siesta might have just put off was would have happened back in July if you had kept running the car.

Let me know how you do with the No. 5 checks.

[FabS6]

Great mate, I think I found the problem. On my garage I had the old coil boots, a set of sparplug wires, the other 2 POS, and 3 spare coils from a UrS4. I catched the coils on my S6, took off the coil boots, plugged the sparkplug wires and made some test with a screwdriver to see if there was a viewable spark and at the same time changing the POS I have... Conclusion, doesn't matter which POS do I use, the coil #2 does a very small and very weak spark and the screwdriver must be at 2mm OR LESS from ground to see that tiny spark...on the rest of the cyls...the spark is strong enough to even keep watching a spark with the screwdriver 1cm away from ground. I made a video so you can watch it and give your opinion or suggestion!!!

http://www.youtube.com/watch?v=sUz5tI1u4lE

[UrS4boy]

Excellent ingenuity to use the 3B/7A spark plug wires to track down your problem coil. Now you need to replace it with a good coil.

One question: What are the hoses and solenoids laying on the injector cover and intake manifold (see photo capture below)? Are you running propane?

[FabS6]

Excellent ingenuity to use the 3B/7A spark plug wires to track down your problem coil. Now you need to replace it with a good coil.

One question: What are the hoses and solenoids laying on the injector cover and intake manifold (see photo capture below)? Are you running propane?

Thanks mate!!! I was just going to start the soldering job to replace the bad coil!!! Yes, those are the LPG injectors! the noise you hear like discharged lifters are the injectors...are pretty noisy....sounds like a diesel when the hood is opened hehe

[UrS4boy]

Thanks mate!!! I was just going to start the soldering job to replace the bad coil!!! Yes, those are the LPG injectors! the noise you hear like discharged lifters are the injectors...are pretty noisy....sounds like a diesel when the hood is opened hehe

What "kit"/brand LPG system? Are you still dual fuel, i.e. can run on gasoline/petrol as well? Where is the LP tank? In the trunk? How big? Driving range?

[FabS6]

What "kit"/brand LPG system? Are you still dual fuel, i.e. can run on gasoline/petrol as well? Where is the LP tank? In the trunk? How big? Driving range?

It's a LOVATO direct port sequential system mate, yes the car runs on gasoline or LPG.. on gasoline as a must during warm-up till it gets 60°C on the main heater exchanger, then it start's to run automacally on LPG (I can manually choose to run on gasoline or lpg). I have a 72L fuel tank on the spare tire place (image above), and it does the same mileage as runing on ron98 gasoline with no power loss I still have to do a good mapping). 130euros for a fuel refill on gasoline and 44euros of LPG! a lot of difference!

[FabS6]

Mate!!!! APPARENTLY and I pray to God for it, the proble has now been solved!!! The whole trouble was coil number 2! After several tests I won this fight! Lol It wouldn't be true if you don't give your support! Thanks a lot mate!!! I will upgrade my coil setup anyway, but at least I can make use of the UrS6 in the meanwhile I get a job and some money! Thank you once and again UrS4boy!!!!

[UrS4boy]

Good job. And you are welcome for any help that I might have provided.

The OE ignition system with the POSs and coil-on-plugs is a good strong system - when all the components are 100%. However as they age, they become very expensive to replace. Until you get a good job, I would just keep the OE system going, using your spare parts. At least now, you are an expert on tracking down the problems.

Good luck with the job hunt.

Dave F.

[FabS6]

yeah!! at least the car is running fine for now... then I will buy some better coils as soon as I have some money available to spend! hehe well track this trouble wasn't fast but... it is at least and finally solved! Thanks a lot to you again mate!!!

My best regards,

Fabio.