HI Guys,

I have a 1996 A4 B5 1.8t Quattro AEB engine

Ok after doing the cambelt and all the tensioners , set of plugs plus water pump as well . I decided to put it on a scan.

I have been having a little misfire accompanied but what I think is the sound of a diaphragm moving.( Just like the old mechanical fuel pumps , if you moved the lever back and forth you would here that funny sound it made) That is the only thing I can think it sounds like.

The misfire is not all way accompanied with the sound and vice a versa.

The misfire can happen at moving of from traffic lights. 3rd gear, foot of intersection coming up! (the sound happens here a lot but with no misfire). Or cursing at 60 just back off the gas misfire.

I have not put the car on a boost gauge or anything like that , but after reading up on everything myself i was leaning toward the N75 valve boost solenoid.

So I get the scan done and here are the codes I get back. 4 in total.

• N75 valve boost solenoid: 01262 (I knew It!)
• Supply Volt B+ : 00532
• Activated charcoal filter : 01247
• Power Supply terminal 30 : 18010

I Believe that the Supply volt and power supply could be related to wrong type of battery in car ( it does not have OE battery) or the battery is faulty ( charging gauge reads ok ) I could be wrong?

Any comments on the codes greatly welcome.

But i was happy to see the N75 show up. I have the part and will install new one.

Any glues guys to what the sound may be?? as I think this is contributing to the sound and the misfire.

And the turbo actuator not working properly and i can hear the diaphragm inside it as the noise seems to come on in boost moments .

Any how will report in after fitment of new N75 solenoid.

Cheers Guys
Smiladon

 

Hi Guys, and Gal's


LoL I see lots of lookers to this post but no reply's


Just an update.. I put the new N75 valve.. I notice a big improvement in power, but still the funny noise and the misfire have not gone.


I will still keep plugging away at it and please if you guys have any idea's please post them up.


Just and FYI I am getting no engine check light coming up.


So could this misfire be down to those power supply fault codes ????


May look at coil pac's next, but I don't think so because she idles like a ***** cat.


ICM perhaps ??? maybe but still the funny noise has me stumped my brain is saying turbo actuator..


Will keep you posted .. and any comments appreciated


Smiladon

 

Hey All,


Just an update.


I have managed to get rid of the sound. It was the Dv valve. Also it had a crazy one on there from a different model car.. they had put to hose adapters on the to main hoses to make it fit. As the two pipes coming out of the Dv housing would have been to be to fit to the genuine hose and the induction hose.


So I have thrown that off and put on a 710N Dv for now.


Still its good to get the power. From the first time I have started this ride, I have got small gains every step of the way. And I still believe their is more to come.


Unfortunately my small misfire is still there.. Would a coil pac be ok just at idle? and go faulty just after the load has come off?? what I mean by that is 3rd gear, just coming into boost take your foot just slightly off the gas, just by a rev counter bar or 2. And she will misfire and if you hold your foot there, the misfire will stay there as long as you have your foot in that position on the throttle. so you feather the throttle to get it back right.


What do you think. Coil Pac/Pac's ?????


Cheers
Smiladon

 

You're not getting any cel's? It might be a coil pack but the best way to check is to switch the non-working cylinder with one that isn't misfiring. Could be a small air leak. Have you done any test with smoke?

 

Hi mate,

Thanks for the reply.

No no CEL coming up. Thing is. It does not miss at idle in fact she purrr very nice.

I am seeing a guy tonight who I have brought a RS4 gear **** of for $50 NZD. He is selling bits off it due to an accident

So i will see if i can take his coil packs and ICM as well

Cheers mate
Steve

 

OK here is an up date,

I have ruled out coil packs.

Put some in from a car that was going sweet and my issue is still there.

AND the guy who I got the coil packs of said " Thats not a misfire thats your throttle body"

Soooo I am now looking at that avenue. will keep you posted

Smiladon

 

Did he specify what about the TB exactly? If you've got vcds you can do an alignment which takes all of 30 seconds.

 

Hi Mate.
The guy I saw last night had about 4 Audi’s in his driveway and I went to his place to buy a new G/lever **** which he was selling on trade me. (New Zealand's version of ebay)

Anyway I mentioned to him my problem with the misfire and asked him to take mine for a spin to get his thoughts. As soon as the car did the stutter he said to me that is not misfire it is most likely to do with the throttle body.
To make sure, he said I will take my good coil packs out of his AEB that he had there and we put them into mine to see if that was the problem. We did that. And the misfire/stutter was still present.

So he said once again that he was sure it was throttle body after what I had told him I had replaced.

So doing a little read up on the forums, there are some posts out there in regards to throttle body issues which are similar to mine. So he is keen to help me out. And one weekend soon I will go back to his place and we will swap parts over from his good motor and try things out from there.
The only concern I have in regards to taking my throttle body of is the throttle body aliment.

As I mentioned I did work for Audi back around 1996 and one of the tech guys still works at the dealership. Today at lunch I was having a talk to him on my issue and he said that it could well be the throttle body. He also said that it was not that critical to do the aliment as they should set them self’s once all plugged back up just do the turn the key on wait a few minutes and you should be all good.

Come in later and I will set it properly on the computer.

So that is where I am at. Will keep you guys informed

Regards
Smiladon

 

I took the throttle body off tonight. Gave it a good clean out with an old toothbrush (Sprayed CRC Brakleen), an another CRC product, Throttle body cleaner.


Just note that be careful, and you should be ok with the gasket between the intake manifold and throttle body.


Was a little bit of crap in there so used the crc. Which did a good job of cleaning it.


Bolted it back up. Did the key on thing for around 30sec and turned the key off. Then start her up?? ...All good... Sweet!


Took her for a spin down the road and the car seemed to accelerate smoother. So the grin started to go and was thinking so far so good...And just when you think. Hey this might of done it.. Happens again.


Still going to try the other Throttle Body. Just to rule that out completely..


Will keep you posted


Smiladon

 

Hey Guys,


Well sorted. Fixed. Was my Throttle Body.


Running with no misfire anymore. Just needs a calibration on the TB to make it perfect.


Smiladon