fastbreak88

2000 1.8tqm with giac 1 bar:

A few days ago I started having a quick surge then throttle cut at WOT in 5th gear. I was running Bkr7e (3 or 4 sets now with no problems) at the time but changed them back to Bkr6e's gapped at .028. When the 7e's were pulled they were very sooted up around the first 3 threads and the ground electrode area.

With the fresh set of Bkr6e's in I developed a fun new problem. At WOT instead of feeling a quick surge and a throttle cut, I get consistent bucking, like multiple rhythmic misfires?

Pulled the bkr6e's just now (maybe 70 to 100 miles on them) and they are already totally fouled with black soot on the threads and white soot on the ground electrode.

I am throwing no cels other than the same cat below efficiency cel I have been throwing for years with my labree hfc.

Running the same coil packs (hitachi e) since I got her at 56k, now at 124k. Run BP 93oct.

I am reading that it could be the icm on top of the air box or maybe I just finally need new coils?

Any insight is greatly appreciated.

@wesome

"click url"

if so; i'm looking into injectors. I'll check the duty cycle (not sure how but i'll figure that out)

then see what numbers i should have versus what I do have.<ul><li><a href="https://forums.audiworld.com/a4/msgs/2870997.phtml">click for pics... i just posted yesterday</a></li></ul>

fastbreak88

So I can add failing injectors into the mix of potentials? Arg.


What leads you to believe it is injectors? I know the fast sooting points to running too rich but my car is only running a 1bar giac chip, nothing fancy like yours. I find it hard to believe all the injectors are failing? One maybe, but all my plugs look like that.

@wesome

I emailed pics to a friend who knows his ****. He got back to me and told me what to look for. This guy has helped me diagnose a ton of stuff and so far he hasn't missed.

He said since my car was sitting for the summer with gas in the injectors; it's possible they are gummed up... looking at other problems my car has had; i can believe that.

Another option would be a boost leak; or hell a leaky valve cover gasket.

I'm pretty certain on my boost leaks + valve cover gasket. Plugs = fine now but i'm going to switch to 6e's

Might just pull the injector and swap to another cylinder. See if it follows.

meh; i want a custom tune anyways in the near future. So i'm going to end up with a new injectors anyways... i'd just like to have this diagnosed

RallyVermont

omgz they look like mine! woot!

@wesome

what was yur problem?

RallyVermont

I'll pull the plugs this weekend though.

I do know since replacing the 02 I have not been running as rich.. at least it smells like it.

Spring cleaning will include the RC injects getting flow tested and cleaned.

@wesome

no codes either.

Pscheoverdrive

Answer was to replace the N249, N75, MAF and primary O2. Also, make sure your 710N is still healthy and it would probably be wise to get a pressure test. SAIS crap leaks and can cause headaches.

Make sure those are done... Best to do it all at once and avoid running rich/lean/rich/lean like I was as each component failed one by one.

Btw - this was on the same MY car w/the same chip.

fastbreak88

I doubt it is the maf (I always throw a cel when the maf goes, twice so far) and the n249, well...

I did that stupid bypass on it (it didn't make any gains or losses that i noticed) about 9k ago. Maybe I added some stress to it then and it broke? I have been chasing down a leak sound from under the manifold so that might be it.


I pressure tested the system about two weeks ago and found nothing, but under the manifold is a different story. Can't see under there.

Do we have any write ups on intake mani removal? Last thing I need to do is break something else.