Socal Smog fail.

[JohnX]

Soo....

Higher ocatne, borrow smaller tires, go first think in the morning when its still cool, run it in a lower gear, and have the smog guy spritz water in the intake (oopps, did I say that), make sure he uses a good fan in front to cool it down and be sure he props the hood up for the whole test.

 

[GrimmJeeper]

Andy, you keep calling BS on my truck overheating when i run 91... im telling you for the fourth time IT DOES.

 

[JohnX]

OK. so everyone without ASE cert (a piece of paper) go home. You don't know anything. :moon:

Thats right. Wheres your paper if thats all it is???

 

[KRAKER]

and yes 91 octane does burn hotter than 87

Sort of. Now correct me if I'm wrong. Isn't the octane rating only a measure of resistence to detonation? That's why it's run in higher compression motors?

 

[JohnX]

Sort of. Now correct me if I'm wrong. Isn't the octane rating only a measure of resistence to detonation? That's why it's run in higher compression motors?

Yep, doesn't really burn hotter, just slower.

 

[GrimmJeeper]

if i wanted this to turn into a peen contest i would have just whipped mine out from the begining. i need to take my kids to thier performance right now, have fun checking inches while im gone.

 

[JohnX]

Okay, I'm done.


Had to get my drama in for the year.

Peace.

 

[daytog19]

Sort of. Now correct me if I'm wrong. Isn't the octane rating only a measure of resistence to detonation? That's why it's run in higher compression motors?

haha u can read thread links

the jeep will run fine on 87 dont put 91 in it for the smog test just check to make sure everything is working fine and go retest my knowledge on this is obviously usless at this point so back to your guys's drama hope i helped with the smog info

 

[KRAKER]

Now now now.... Just cause mine is bigger .!..!.

 

[silverslk]

No. runnning higher octane would make HC's go up. The NOx can also be caused by a lean conditon/ or vacuum leak.

So, because it resists burning (igniting quickly) it would lead to possible unburned fuel?

 

[KRAKER]

Exactly... That could be whats causing Mike to run hot. Burning fuel out the exhaust.

 

[silverslk]

I am not doubting what Mike said about his jeep running hot on 91. Just trying to figure it out. I failed the same high NOX and I just filled up with 91 and am wondering if I screwed myself.

But if the gas isnt burned completely wouldn't that , in effect, lower chamber temps because of a smaller flame?

 

[KRAKER]

I doubt high octane will cause a Nox issue

 

[erikwylie]

Two very likely solutions...

1. borrow some smaller tires and run it again.
2. Have the smog guy run it at a higher rpm (lower gear). Usually one gear down will not get it outside the rpm limit range, but it will raise the rpm enough to lessen the load on the engine and thereby reduce NOx

Doing both of these, plus dumping about 1 cup of water in oil (I know don't flame) but it worked and I passed on the nox by 2 points!!!

 

[Leep]

ok, just checked what we did when we smogged tims jeep when it failed. We changed plugs, wires, cap, rotor, seafoam and a tank of 87 with seafoam and it passed.

The first attempt we had a new(er) cat and muffler so we now know that was not the problem.

Just my .02 worth and dont hate me for posting what worked for us.

 

[silverslk]

funny thing is my RPM for test was the same on 33's and on 225's.......Can't explain it except maybe the trans upshifted again to compensate. My smog guy (not my buddy) said they are told to just put it in drive. I guess I have to find a guy who will test in a lower gear.

 

[silverslk]

ok, just checked what we did when we smogged tims jeep when it failed. We changed plugs, wires, cap, rotor, seafoam and a tank of 87 with seafoam and it passed.

The first attempt we had a new(er) cat and muffler so we now know that was not the problem.

Just my .02 worth and dont hate me for posting what worked for us.

Thats what I did too Dennis (along with O2 and Coil) and HC and CO dropped but NOX jumped. That is why (along with Scott's suggestion) I am gonna try a heat range colder plug. See if I can get just enough heat out the chamber to help.

 

[xtimmax]

ok, just checked what we did when we smogged tims jeep when it failed. We changed plugs, wires, cap, rotor, seafoam and a tank of 87 with seafoam and it passed.

The first attempt we had a new(er) cat and muffler so we now know that was not the problem.

Just my .02 worth and dont hate me for posting what worked for us.

First attempt was normal.. it failed.
I then changed the cat.. it failed
That is when i did the plugs, wires, cap, rotor, seafoam etc.. it passed.

But being my jeep is an 87 it is a renix. I believe this whole thread is regarding the 91-96 jeeps which are HOs like mike stated in his original post.

 

[GSequoia]

funny thing is my RPM for test was the same on 33's and on 225's.......Can't explain it except maybe the trans upshifted again to compensate. My smog guy (not my buddy) said they are told to just put it in drive. I guess I have to find a guy who will test in a lower gear.

Got a second gear switch? If so put in it 2nd gear mode, that will keep it out of overdrive. (you won't have first either but they only test at cruising speeds so it should be good)


Smog guys always run it a gear too high, they had my Chief (five speed) pretty damn close to stalling, they must have been in fourth gear at the 15mph test!

 

[silverslk]

First attempt was normal.. it failed.
I then changed the cat.. it failed
That is when i did the plugs, wires, cap, rotor, seafoam etc.. it passed.

But being my jeep is an 87 it is a renix. I believe this whole thread is regarding the 91-96 jeeps which are HOs like mike stated in his original post.

And what really sucks is that they lowered the limits ALOT form renix to HO Tim. We only get like 770ppm NOX where I believe you get over 1000ppm.