Think I found the problem!

bugjuice · Post by **bugjuice** » Fri Feb 28, 2014 9:22 am

So some time last year, the car started misfiring and the CEL came on to acknowledge it, along with the knock sensor. I thought that the knock sensor just came about because the misfire cause a knock and threw it out. I bought NGK-R plugs from the US ($50 for 6 vs $75 each from Repco!!) and a new plenum, and got Yellow Jacket coils from Oz, hoping that it'd be the fix it wanted, but nope, still ran like crap and half power. No CEL tho.. So got it checked and the knock sensor was still causing the issue. Finally pulled it all apart yesterday, and found this! Whilst I was at it, I pulled the injectors out for cleaning and servicing at Injector Tech (thought might as well, and they match them within 5% as part of the service) and saw one of the injectors had 3 holes and an almost-oval, which also probably wasn't helping!! So hoping to get them back today, back in the car, and we'll see if she has full power back, and drinking the normal amount instead of doubles!!

Also glad that I thought ahead and bought the sub loom from the US too, so so glad!!! Tbh, I think it's actually a piss poor place to put anything vulnerable like that, but hey.. Also adding a thermal lower plenum gasket, Nissan wants $150+GST for a new gasket (all been fine to reuse btw), or $30 for a thermal 'performance' gasket from the US!! We get so ripped off here

BRONZEE · Post by **BRONZEE** » Fri Feb 28, 2014 12:52 pm

Will be interest to hear how she's going with everything sorted out.

bugjuice · Post by **bugjuice** » Fri Feb 28, 2014 1:29 pm

Well here's something even more interesting; just got back from picking up the injectors (he said the spray pattern was all over the place, and some lean some rich, so excited about the injectors now!), and Phil at Injector Tech said that it's not heat deterioration - it's mice. Bit shocked, but we did have a few mice running around before this happened, and we got cats, and now no mice. And then the car played up. So may be they did the damage, and it's been holding out all this time until the vibes just killed it..?? Don't know. He also showed it to another mechanic to double check, but yep, unlikely to be heat damage!!

maukuzed · Post by **maukuzed** » Fri Feb 28, 2014 3:28 pm

Yeah had similar problem some years back , a rat decided to make a nest on a nice warm Toyota surf engine block in the middle of winter ! amazing how much damage it did, chewed up cables hoses etc made a real mess took a couple of days and a fair few bucks to sort it too . the cats were useless ,not interested in a big rat so rat poison did the trick in the end ... Good luck hopefully you've got it sorted

bugjuice · Post by **bugjuice** » Fri Feb 28, 2014 4:13 pm

yeah, hope I've got the mice sorted too!!

All back together and running now, bu hasn't fixed the problem tho

Was running about 70%, I'd give it about 90% now. I want to get the ECU reset and then see what happens (I've done the learning stuff for idle, air and throttle etc). After that, I guess it's on the dyno and see if it's just fueling wrong or something..? And see if the ECU says anything more. Else I'm outta ideas for the moment!

OMSIN · Post by **OMSIN** » Fri Feb 28, 2014 5:36 pm

02 sensors full of carbon / unburnt fuel?

kirihi · Post by **kirihi** » Fri Feb 28, 2014 6:12 pm

After reading all of this, I think I'll reset the mouse traps in the garage tonight!!!

bugjuice · Post by **bugjuice** » Fri Feb 28, 2014 8:07 pm

one of the four O2 sensors are new.. I could pull them out and clean them (if you can clean them.. I'd rather not buy more if I can avoid it!), but they're not coming up on the ECU diagnostics..

Baker93 · Post by **Baker93** » Sat Mar 01, 2014 6:53 am

Yep definitely looks like the type of damage that rats and mice do. They love cables, flexi conduit and ducting. I run an electrical contracting business and we see this type of damage all the time in wiring looms of machinery and in houses and buildings. Pest control /rodent expert tells me they chew on the stuff to stimulate tooth growth. Often cables end up covered in sticky rat saliva goo. It lovely to work in !!! That's a bit of useless non car related info for the day.

OMSIN · Post by **OMSIN** » Sat Mar 01, 2014 9:29 am

Baker93 wrote:Yep definitely looks like the type of damage that rats and mice do. They love cables, flexi conduit and ducting. I run an electrical contracting business and we see this type of damage all the time in wiring looms of machinery and in houses and buildings. Pest control /rodent expert tells me they chew on the stuff to stimulate tooth growth. Often cables end up covered in sticky rat saliva goo. It lovely to work in !!! That's a bit of useless non car related info for the day.

They often chew the data cables and not the 230v ones, wish they would every now and then - teach them a lesson

OMSIN · Post by **OMSIN** » Sat Mar 01, 2014 9:31 am

bugjuice wrote:one of the four O2 sensors are new.. I could pull them out and clean them (if you can clean them.. I'd rather not buy more if I can avoid it!), but they're not coming up on the ECU diagnostics..

CRC electrical contact cleaner works well, I used it to remove the gunge in my upper / lower plenum. Otherwise brake cleaner should have the same effect

bugjuice · Post by **bugjuice** » Sat Mar 01, 2014 4:02 pm

If the O2 sensors were bunged up tho, wouldn't they flag on the ECU as a problem?
One out of three are new, so I guess it could make sense. Could the car need tuning to the new O2 sensor, and that's why it's running rough..?? Don't mind pulling them all and cleaning them up, but only if it's for the better!

bugjuice · Post by **bugjuice** » Sat Mar 01, 2014 9:09 pm

So I took the battery off over night and then ran it again today, feels so much strong, almost like a sports car again!! Just feels like it's running too rich down low. Might pull the O2s out and give them a clean, if that's a good idea..?? Else I'm thinking a dyno run might be what's needed next..

Been thinking more regarding cleaning the O2s - actually makes sense, and I don't know why I didn't see it before! I replaced the sensor in the header/collector because it became unplugged and I thought it had just died. I replaced that, and that was it. I never did anything with the sensor down the line, which is probably clogged up! So I'm going to pull the new one out, clean it, replace the 2nd one with the spare new sensor, pull the other two and clean those too. Then we'll see!

OMSIN · Post by **OMSIN** » Sun Mar 02, 2014 7:16 pm

The skyline coil packs which are known to be crap, failed on my R34. And of course after awhile if too much crap goes through the 02 sensor they they stop working, had to replace mine a few times while I had coil pack problems - even tho the o2 sensor had only just been replaced, the un burnt fuel and what not killed it again

When you plug in the diagnostic thing that the mechanic had you could see how the 02 sensor was working, its meant to search up and down the range quick quickly, when they aren't working they usually only scan half as fast and not the whole range

bugjuice · Post by **bugjuice** » Sun Mar 02, 2014 7:44 pm

yeah, well I was back under the car today. I pulled out the one I stuck in the other month and cleaned it, and replaced the 2nd sensor just down from that with the other new one I was trying to sell. I couldn't get the top one out of the other side, but got the 2nd out, and it wasn't bad (altho I can't really see if it is or not inside!). Cleaned that one tho, and no black stuff ran out. Took the car for another spin, and it's now around 95% back. Seems to bog in the low revs slightly, so might pull and clean the plugs, and then I want to get a computer on and see what else is going on. Starting to run out of ideas! Which is why I'm also thinking a good tune is what's next (after a new exhaust!)