Hmmm Any one has ideas?

 

I probably won't find out for sure till the header swap which I might get to this week. I got some things done today during the intake job. I took off the egr system and and a few parts of the air system. I have to send the pcm off for the tune so while it's away I'll try to get the headers in.

 

I have had a scanmaster in the past and watched as timing was pulled when I had a leaky header gasket. It definitely will affect fuel consumption and performance. I would put it on knock retard setting and watch it pull more and more as the ticking got louder from exhaust. (I was having recurrent problems with the header loosening from #8 port)

If you listen closely in my vid below you can hear it.

Stay on top of your bolts after you install you headers until everything settles in place.

 

It is using a lot of gas. The guy that installed my gears also put in the set in my old camaro. He could tell a difference in the performance between the two. My old z felt much stronger. That leak is killing performance. I can't wait to get headers in .

I got a set of percys split lock header bolts. Hopefully I won't have to mess with them much.

 

Your gasket will compress whether or not your bolts stay locked in position. It will for sure run better, but you going to have to re tighten a few times, if I had to guess. Better to bite the bullet then to burn your gasket.

Its good that your running diagnostics, and pinpointing things.

 

I may be in the minority - I don't like the idea of a knock sensor on a modified car. There are just too many sources of "false knock". Yes, I understand the benefits but think that with good tuning and proper operation, the KS just isn't needed. Anyway, as far as this situation goes you should fix that exhaust leak! You are losing a ton of power with 12 degrees taken out! I think it can take out even more, but it has been a while since my car had a working KS so I can't remember for sure.

Rich

 

Throw 12 degrees of knock retard (stock programming allows 15) on top of one bank of the engine running pig rich from the huge exhaust leak, and performance is going to suck - no question about it.

 

I seen it spike as much as 17 deg briefly. No doubt about it that it doesn't run as well as it should.

 

Finished installing my longtubes today. Started it up (straight headers still) and I'm seeing no timing being pulled! I revved it up several times and the scanmaster read 0.0 the whole time. I would take it for a drive but my neighbor is a state trooper. Don't think he would appreciate it lol. I'll probably finish the ypipe sometime this week and hopefully confirm the problem is gone.

 

Great! I had a feeling you were going to get rid of the knock after you did the install.

 

It's back! I got my ypipe hooked up today and took it for a drive. No knock retard whatsoever. I drive it for about 4 miles turn around and come back home. I got on it a little bit, hmm not running as strong as I expected. I get back home and pull into the driveway. It starts idling kinda lower than normal and has a bit of a miss . The longer I let it idle the worse the miss got it seemed. Also it started backfiring slightly when revving it up. I looked at the scanmaster and about 6 deg timing was being pulled again as I revved it. WTF? I started pulling plug wires trying to find if it's a certain cylinder but had no luck. What should I be checking?

Here is a really crappy vid. Some of the noise is the rear o2 sensor holes in the ypipe that I still need to plug.

http://s20.photobucket.com/albums/b2...=Video0058.flv

 

BTW I know it is coming from the passenger side of the engine. The o2 sensor on that side was a pain to get out of the manifold. I had to soak it in pb blaster overnight but didn't see any pb on the "sensor" part. Could this have done something to it? I forgot to look at the o2 values on that side.

I should also add a few weeks ago I got a code 36 (high res) come up on the scanmaster. It only happened once and never came back. Could this be the opti crapping out on me? Why would timing be pulled again, though not nearly as bad?

 

Maybe post #4 has the answer.

You shouldn't soak the outside of an O2 sensor with anything. There is a vent passage on the outside, that allows ambient air to reach the outside of the zirconium sensing thimble, and it is the difference between the O2 content of the air on the outside of the thimble and the O2 content of the exhaust on the inside of the thimble that generates the sensor voltage. I've seen O2 sensors contaminated by exhaust leaks, dripping oil and power steering fluid, etc.

 

I had both valve covers off while I replaced the intake gaskets. I didn't see anything out of the ordinary. It's possible I missed something. What exactly should I be looking for?

 

I think I found the problem. The bottom o-ring on injector 4 is not seated right. I don't know how I missed it before but there is a loud sucking sound from there. Hopefully this will cure it. I guess that would explain the low o2 readings on that side?

BTW I pulled the valve pan again and everything looks fine.