High HC=Misfire?

[87GNSteve]

Here is the story part II:
Stock 87T 115K
Tuned up, new pcv, o2, coil, mod, r44ts plugs, seafoamed, and misc vac lines
failed with a 2.300 HC
Then I installed new 32lb inj, billet alum vac mod, welded cracked header, MSD ignition wires.
Failed with a 2.500 HC!
WTH?!
What else causes misfire? Car drives smooth idle isnt the best but alot better after I did all this work.
I did a scan at cruise yesterday 40-45 mph GM chip.
Temp: 197-200* BLM: 107-115 INT:128 o2s: drop very low when I release pedal up high as 600-790 MAF: is suspect 236 max @ WOT.(but I dont think that would cause hi HC/misfire)
Could the NEW coil and/or module be no good, the mod is a auto zone and the coil unkown brand.

 

[gofstbuick]

Stock PCV valve or no? I hope the answer is yes. Is the EGR vavle stock? Look at answer to first question. Is the EGR valve leaking? How do you know it is misfire? High HC coupled with High CO and really low NOx could be too rich. What is your plugs gapped at? 0.32-.0.36 inch. I am kind of partial to 1 or 2 steps colder (CR43TS or CR42TS).

 

[87GNSteve]

readings were:\
HC 2.5 limit .8
CO 9.2 ......15.
Nox 0.4.......2.0

PCV is Deutch brand made in usa, passenger side pcv to turbo inlet is vented and blocked. I havent looked closley at the EGR doesnt appear like its leaking...

 

[gofstbuick]

First off, I hope you haved the factory PCV valve. If so clean it up and put it back in. Also, it appears that the emissions are rich, especially since BLMs are low, HC and CO are high and NOx is low. Do you have an adjustable fuel pressure regulator? If so lower fuel pressure. If you're running a 237 regulator, return to a 233 regulator.

 

[chopped39]

What Does The Fail Trace Look Like That They Gave You. When Do The Hcs Increase? Make Sure You Have No Gas Leaks .make Sure You Have No Major Oil Leaks. Because When They Put That Fan In Front Your Car Its Not To Cool It Down .its To Get A Full Sample Of What Is Coming Off Yor Car Let Alone Whats Coming Out Of Exhaust. Make Sure Regulator Is Not Leaking Fuel From Vacumm Line.check Egr Make Sure Its Not Leaking Or Stuck Open.tap On It With Small Hammer And See If Idle Smooths Out . Don't Hit To Hard. Or Just Remove It And See If Pintle Is Stuck.is Car Going Into Closed Loop. Fail Trace Will Show If Your Getting Any Type Of Fuel Control.post Fail Trace.

 

[87GNSteve]

The graph chart is very spiked, looks like everytime they accelerated to maintain speed.

 

[chopped39]

Does It Look Like It Spikes Right Away And Stays High Does This Car Have A Cat On It? Does The Car Smoke At All ? Check Cat Temp Before And After Cat. Make Sure Its Working .hotter Towards Rear Lets You Know If Converter Is Lighting Off If Same Temp Cat May Be Bad. If Cat Is Not Functioning Properly Or Missing Exhaust Flows To Fast Past O2 Causing More Fuel To Be Dumped . What Are 02 Crosscounts. What Kind Of Scan Tool Are You Using.any Codes?
Does This Car Have A Misfire? Spray Coil Dowm With Light Mist Of Water And See If It Gets Worse. Or Take Test Light Ground It And Then Move Around Coil And Wires And See If You Can Find Any Arching Wire Or Coil . Be Real Careful Doing This. That Coil Is Not Forgiving. How Did Wires Look On Module? Delco Modules Are The Best. I Have Installed Bad Modules Before. If You Know Someone With Scope You Be Able To See If Module Is Working Or Not. Where At In Ill Are You. I Might Be Able To Get It In My Friends Shop To Scope It. I Am In Addison Pm Me

 

[87GNSteve]

Car spikes and drops-doesnt stay high, no smoke, Cat is 1 yr old.I am using Turbolink no codes,
It doesnt feel/sound like misfire. and the coil and wiring looked mint.
I might just abandon trying to pass becuse i am moving away in a month what are they going to do?

 

[Hacksaw]

What did the old plugs look like? If one looks OK, but the other look lean or rich, then that injector is flakey. Take the EGR valve off, & check to see if it's stuck slightly open, & clean it as needed, and use a new gasket. If doesn't smoke or use a lot of oil, then the rings & valve guides are OK. Is the air filter clean? Did you clear the ECM after the last work you did?

 

[chopped39]

Who put cat on car? because if it is aftermarket that could be the problem. aftermarket cats suck. if they last more than the 25000 mile warranty your lucky. and that is on a car with no mods and running perfect. once you add mods cut that in half and then some.you put one of those on a new car it will set a cat code in no time. sometimes on test drive. i have heard people say they past without a cat. Well you know how the great state of il is with the IM 240 test. no cat no test. and when they start testing for nox gas. were screwed. I would bring car to shop that put cat on it and tell them car failed test and have them put new one on it and retest it. and dont tell them about injectors. tell them they are new stock ones if they look . because that extra fuel takes it toll on the cat. And make sure cat is big enough for car. best of luck

 

[87GNSteve]

The previous owner changed the cat....has low miles on it. My car is registered in WI and they arent busting my chops as of yet and like I said I am outta here in a month and 3 days! Heading south...so I'll see where I wind up exactly and hopefully no where a emissions test is required.