Stock Coils Resistance Info!

[FabS6]

Hello guys... unfortunately I am still having the engine running rought like a kind of misfiring or something like that especially under light engine loads or accelerating on any gear right from idle rpm.

The POS are fine, injectors fine, new coils ground wire, coil-to-sparkplugs boots have less of 30K miles, sparkplugs brand new... the last thing I can think it is the problem, are the coils! I have right here my 5 stock coils...can anyone tell me which is the coil resistance on the stock ones? I was thinking on the O2 sensor too but... it doesn't seems to be a lambda sensor failure. Suggestions? Opinions? Thanks in advance

[BrianSmith_S2]

Hello guys... unfortunately I am still having the engine running rought like a kind of misfiring or something like that especially under light engine loads or accelerating on any gear right from idle rpm.

The POS are fine, injectors fine, new coils ground wire, coil-to-sparkplugs boots have less of 30K miles, sparkplugs brand new... the last thing I can think it is the problem, are the coils! I have right here my 5 stock coils...can anyone tell me which is the coil resistance on the stock ones? I was thinking on the O2 sensor too but... it doesn't seems to be a lambda sensor failure. Suggestions? Opinions? Thanks in advance

What fault codes are you getting?

[FabS6]

What fault codes are you getting?

I don't know mate...I don't have the vag-com yet! I just noticed a fatal wire insulation cooking inside the coil's place on the aan... are worst than a sausage after 3 years in hell! On the pic you can barely see that it had the wire insulation off and noticed WHY the last owner added some red silicone around the wires...

[UrS4boy]

Missing and Hesitation Diagnostic Procedures

What fault codes are you getting?

OE POS and Coils do not throw ANY codes when they fail. That makes them so much fun.

Here is a Missing and Hesitation Diagnostic that can be used to figure out the problem(s) (with links to POS info and POS and harness pin swapping hints):

http://forums.quattroworld.com/s4s6/msgs/22611.phtml

[UrS4boy]

S64/S115 Coil Power Fuse Info

I don't know mate...I don't have the vag-com yet! I just noticed a fatal wire insulation cooking inside the coil's place on the aan... are worst than a sausage after 3 years in hell! On the pic you can barely see that it had the wire insulation off and noticed WHY the last owner added some red silicone around the wires...

When the AAN (or ABY or ADU) coil wires lose their insulation due to age and heat, they are very likely to short out to the coil cover or the head. For a C4 UrS, this will blow the S64 (UrS4) or S115 (UrS6) fuse, as explained in this post:

http://www.s2forum.com/forum/showthread.php?p=593754

[FabS6]

I see...! well thanks fot your info URS4boy! I'm still trying to solve the insulation problem on 3 coils. I think this a reason to upgrade my coil system...in the meanwhile I hope to make use of my car even at low loads. What is the correct resistance of the coils? If it's lower on one, could that be the problem? This is really a headache...especially if you are jobless

[FabS6]

Okay... coil's insulation wire problem: SOLVED. Engine hesitation, it's still there. WTF is going on?????? Coils are maybe gone?????? This is freaking me out!!!

[UrS4boy]

Okay... coil's insulation wire problem: SOLVED. Engine hesitation, it's still there. WTF is going on?????? Coils are maybe gone?????? This is freaking me out!!!

Did you test the POSs and Coils as per the DIY procedure I posted above?

BTW, the resistance of the coils is of little use. Better to test the strength of the spark as shown in the DIY.

[FabS6]

Did you test the POSs and Coils as per the DIY procedure I posted above?

BTW, the resistance of the coils is of little use. Better to test the strength of the spark as shown in the DIY.

I did everything but testing the coils with that strange coil tester mate...! I had 2 other POS from another AAN I had before... I changed them and problem is still being there! I wouldn't want to spend RIGHT NOW 300euro for the coil set and keeping that hesitation even with new coils... I was going to buy a new set, but not in this moment I don't have a job

[UrS4boy]

I did everything but testing the coils with that strange coil tester mate...! I had 2 other POS from another AAN I had before... I changed them and problem is still being there! I wouldn't want to spend RIGHT NOW 300euro for the coil set and keeping that hesitation even with new coils... I was going to buy a new set, but not in this moment I don't have a job

Well if you changed the POSs and the problem is still there, it either means that your spare POSs are cr@p or one or more of the coils are bad. Have you isolated which cylinder has the problem, e.g. checking for missing at idle by pulling the injector electrical connections one at a time as per the DIY?

[FabS6]

I did disconnect each injector at once an observe if the problem stills there ... but running on 4cyls is hard to detect it! Yeah I thought if my old POS were fu**ed too. I'll make another test disconnecting the injectors mate

[FabS6]

Well if you changed the POSs and the problem is still there, it either means that your spare POSs are cr@p or one or more of the coils are bad. Have you isolated which cylinder has the problem, e.g. checking for missing at idle by pulling the injector electrical connections one at a time as per the DIY?

Okay mate... I did change the POS again with the other two I had...maybe are cr@p and are causing the hesitation like the stock one on my Ur, so I have 4 POS, I exchanged them all and the failure still there... It's probably that I maybe found something disconnecting cyl #5...it's hard to detect it running on 4cyl so I can't be sure of it at 100%!

[UrS4boy]

It's probably that I maybe found something disconnecting cyl #5...it's hard to detect it running on 4cyl so I can't be sure of it at 100%!

The injector disconnection trick is that when you disconnect an injector electrical plug and the miss gets worse, it is NOT that cylinder. So you reconnect and try another. When you disconnect the injector electrical plug and the miss does NOT get worse, then you have located the problem cylinder. Running on 4 out of 5 is rough but disconnecting a good cylinder and running on 3 of 5 will be rougher. Hopefully this is what lead you to believe it is cylinder no. 5.

If you can find (borrow?) one absolutely positively good POS, even a brown one from a V6, and the problem goes away, then you have a dead POS channel on No. 5. That would be good news since you have a spare channel on that POS (only 2 of the 3 are used. Assuming that somebody hasn't previously swapped channels, you could swap pins to use the unused good channel). However, you might be better off just using a good used brown V6 POS for cylinders 4 and 5 - unless you think you can swap the pins.

[FabS6]

The injector disconnection trick is that when you disconnect an injector electrical plug and the miss gets worse, it is NOT that cylinder. So you reconnect and try another. When you disconnect the injector electrical plug and the miss does NOT get worse, then you have located the problem cylinder. Running on 4 out of 5 is rough but disconnecting a good cylinder and running on 3 of 5 will be rougher. Hopefully this is what lead you to believe it is cylinder no. 5.

If you can find (borrow?) one absolutely positively good POS, even a brown one from a V6, and the problem goes away, then you have a dead POS channel on No. 5. That would be good news since you have a spare channel on that POS (only 2 of the 3 are used. Assuming that somebody hasn't previously swapped channels, you could swap pins to use the unused good channel). However, you might be better off just using a good used brown V6 POS for cylinders 4 and 5 - unless you think you can swap the pins.

I say that of cyl 5 cuz I realized that disconnecting it the engine ran ""smoother"" on 4cyl without that strange hesitation...but unfortunately I am not sure about it! So you say about buy a POS from a v6 then...buying it used but...who knows if it fine mate
Do you know what is strange?? I stopped the car w/o any failure on it on july 22nd... I went off for 2 months, then on october 2nd I made an oil change, took out the plugs, run the engine with the starter motor for a few secs till there was some oil pressure on the system, then replug the sparkplugs and the coils.... then start the engine and....surprise!!!! a bad hesitation that almost a month later, I can't find out WTF is it!

I have a set coil boots somewhere here from my old aan, I will replace the urs6's with these ones that were good when I had my aan CQ...just for curiosity.

[UrS4boy]

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.