248/232 cam swap cause lean condition

[iitywygms]

93 s13 with a ka24de with intake and exhaust.
So a few years ago I did the 248/232 cam swap. I just recently had to get a smog done. (Good ol California)
Anyway, the engine now runs lean. The maf, egr, o2 sensor have all been changed and it is still running lean.
Could the cam swap cause this lean condition?

[numbnuts240]

i ran my car through emissions with the 248/232 swap and an entire tune-up (minus pcv) and the car passed with flying colors.

[iitywygms]

Mods I posted up in the wrong forum. Can this be moved to the correct forum?

[themadscientist]

One possible effect of long duration cams is the charge blowing out the exhaust valve during overlap. Those cams are nowhere big enough to do that. Are you sure you didn't install one one tooth off. Double check. You may have an advanced exhaust cam or a retarded intake cam.
And I'll move this fer ya.

[Dattebayo]

retarded

Yeah, that's probably it right there.

[iitywygms]

Hmm, I would not think I have it one tooth off. It runs like a champ, smooth with no surge or anything. If it is off it has been like that for two years.
And I take have taken second and third at my local competition.
I did redrill the cam gear using this thread.
djpantsspecr-s-diy-adjustable-cam-writeup-t199832.html (the pics are gone now)
Maybe I have it screwed up somehow? I guess I should start advancing the intake cam???


I

[themadscientist]

No, you should verify it is in fact timed correctly. It's a shot in the dark, don't go messing with what you have until you confirm it is actually incorrect.

[iitywygms]

Latest results after o2 sensor swap

[iitywygms]

No, you should verify it is in fact timed correctly. It's a shot in the dark, don't go messing with what you have until you confirm it is actually incorrect.

Is there a thread or a how to that you can point me to?
Sorry for not searching but I am in a rush. I got a fix it ticket for my tags that is due in a week. Gotta get it smoged before I can get the tags and time is a running out.
I have seen the how-to's that say when at top dead centre the lobs should be pointing away from each other. But that does not seem like a very exacting way of checking if I am off a few degrees one way or the other.

[themadscientist]

I'm the CA18/FJ20 guy, surry. I'm sure one of the KA gurus can help.

[iitywygms]

Um, okay yah. I just read this post on how to check cam timing.
http://www.ka-t.org/forums/viewtopic.php?t=41963

To much work for me. I might just buy the jwt gear and use it.
My drill job on the cam gear might be off a little, which can result in large timing errors, from what I understand.

One really odd note from the smog guy today. He said that removing the air filter from the short air intake brings the numbers more in line???????? Wtf???? So removing the filter makes the car run richer?
IDK. We are going to put the original intake back on and see if it will pass smog. Just so I can get my tags.
I still need to figure out exactly what is going on after that.

[iitywygms]

So. The cat/o2sensor/maf have been replaced. Still runs with high no. The egr test good.
This weekend I will check my intake cam to see if it is retarded.
If it is, and I set it correctly, (advance it 2.5 degrees using a redrilled cam gear) the car should pass correct?

[iitywygms]

If the intake and or exhaust was off by one tooth you would defiantly notice correct? A lopy idle or something.
It would not sound factory correct?

[motoman399]

http://www.youtube.com/watch?v=oZPMhra0sz0

^ that is a video i made to help a guy out one time. it might help you. that is s13 cams in an s14 (shouldnt matter) but they are in stock postition. good luck

[iitywygms]

Yeah I finally found that video a few days ago. Nice an informative thanks for posting it.
So
I have a new egr, bpt, cat, o2 sensor, and maf sensor. All vacuum lines are clean and no lose connections.
Still has high nox. The cams are now back to stock 240/248. ECU has been reset.
I am going to have to sell this thing if I cant smog it.
WTF!!!!!!!

[motoman399]

what about your catalytic converter?

im really glad people are seeing the vid. i honestly had no idea that anyone would ever see it lol.

[iitywygms]

Yeah, did the converter too. Called it cat in the previous post.

[motoman399]

meow.. sorry just didnt read again and forgot that i had already read it lol MEOW!!!

[iitywygms]

So, a month and a half later. I got an exemption so I can get the tags.
Now the nox are at 3000 at 15mph.
Is it possible to somehow screw up the bottom timing chain? I have checked my cam position multiple times. they are pointing slightly upward, away from centre. Just like all the photos I see. I have 8 links between the cam marks.
Thing is, my nox went up to 3000 after I reset the cams. But I know I set them correct. I am thinking maybe I screwed something up but have no idea what it could be. The bottom chain cannot get fd up unless I take it off right?
I put the crank at tdc, verified by setting a screwdriver on the #1 cylinder and watching it. It is at the top when the timing marks line up, so I know it is right. The distributor is at the correct position, timing is good. Cams look correct. Car runs great above 2000 rpm. Smooth and steady with good power. Idles okay, with slight misfire and occasional stumble. But of course, extremely high nox.
What am I screwing up?????????????????????

[motoman399]

pull the timing chain covers off completely and reset both chains. it is possible that you got your top chain one tooth off when you changed out your cams. do that and then have them put the probe in your rear. report back lol

[iitywygms]

pull the timing chain covers off completely and reset both chains. it is possible that you got your top chain one tooth off when you changed out your cams. do that and then have them put the probe in your rear. report back lol

Thanks for the advice.
I don't necessarily need to pull everything off do I? Couldn't I just advance or retard each cam 1 tooth?

[motoman399]

well im not really sure how that works with there being two chains. if it was only one chain i would say yes but it might be a little different with the two.. should be only a few hours and some rtv, if i was you i would do it all just so you KNOW its correct.

[iitywygms]

So I took everything off and checked it out. The cam timing is correct.
So, its not my cams causing the lean condition. Or the mafs, o2 sensor, cat converter, egr, tps, ecu, injectors, or fuel pump, or fuel filter, or back pressure transducer valve. Or the plutonium p238 explosive space modjulator,
WTF!

[motoman399]

lol holy crap. im lost. have you checked compression? done a leak down? maybe you have a blown head gasket or cracked head? burnt valve? i dont really know just throwing out ideas..