Just passed smog test. Hydrocarbons a bit high

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Here are 3 smog test results 12 years apart on same vehicle/engine, most recent 2017 on bottom:

smogcomparison2017.jpg


In a previous thread showing macro pics of my previous bosch +2 sparkplugs, Trav said the coil could be on its way out.

All the other ignition components are new, Taylor 8mm wires, NGK Gpower platinum plugs, new airtex/wells distributor cap and rotor.

It is a 12 or 13 year old Echlin.

Thinking the replacement will be an Airtex/Wells.

http://www.rockauto.com/en/moreinfo.php?pk=2060580&cc=1073506&jsn=438

I was impressed with their distributor cap
 
You have good wires plugs and cap n rotor throw in a nice coil like an accel, flame thrhrower or screamin demon and open the gap a bit to something like 60 thousandths. On my old 1994 grand cherokee with 318 i had taylor wires, summit racing cap and rotor and a screamin demon coil with plugs gapped at 65 and it ran like a swiss watch.
 
I would not worry over it. The readings are not drastically different from 2005 and would pass with flying colors in my state.. You passed and do not need to worry till next test time.Why look for problems that may not exist. Your probably dealing with a converter which is slowly losing its effectiveness or a small vacuum leak.
 
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I'd find something else to worry about, you passed. The engine and emissions system are older with more time, miles, and wear on it than the last test. That in and of itself can make slight changes in emissions.
 
Instead of changing the coil, you could try closing the gap between the rotor and the individual poles in the distributor cap. I usually modify the rotor to accomplish this.
 
CO has also always been a bit high, and NO kind of low (at least it was back in the first test when the converter was new). This suggests a rich run not misfiring.
 
+1

And, run a new dedicated ground lead from the battery Neg ( - ) pinch bolt to the intake and then on to the firewall. #8 wire or bigger with crimped and soldered lugs the size to fit the bolts chosen. It will help the ECU see all the engine sensor circuits with a clean "O" baseline, so the injection will be better and more stable.

Coils don't fade away. They either work, or are shorted internally and don't. They can be intermittent with heat. But they do not slowly die.
 
Originally Posted By: mk378
CO has also always been a bit high, and NO kind of low (at least it was back in the first test when the converter was new). This suggests a rich run not misfiring.

The CO isn't high. He's atleast half of the limit.
 
I just got a handed down 1994 Crown Vic with 200k, it only blew 5ppm on nasty plugs. I only knew because I have since changed them. I'd think one of the sensors or cat is starting to go on your vehicle. My friends 99 dodge 360 passed with a broom sticked cat a few years ago and it blew higher numbers similar to yours.
 
Originally Posted By: BrocLuno
+1



Coils don't fade away. They either work, or are shorted internally and don't. They can be intermittent with heat. But they do not slowly die.
I used to think that too. Until I had one that would run poorly and raw gas collected in the exhaust and touched off. One of my BMW buddies reported a similar situation. These were the typical can type coils. On the whole reliable. easy to replace.
 
I drive my truck less than 500 miles a year so between smog checks I'm not exactly wearing out parts. Every time I get it tested it shows different totals sometimes vastly different numbers with no hardware changes. Before I start spending money I would just go on nice freeway trip with a few WOT pulls and then pull into the smog station with it nice and hot.
 
It will be two years before I get another smog test, as I don't have a friend with a sniffer just to run that portion of the test, and will not be paying just to see the results of any changes I might make.

I replaced the last coil as oil was weeping out of the tower. These are mounted on their sides.

I had pulled into station with several WOT pulls and with it as hot as the engine gets. They pulled in onto the rollers almost immediately.

With all new ignition components, but the coil, I was hoping for better HC readings

A new coil is about 25$
 
I wouldn't lose sleep over this. I'd buy the best coil you can afford. Seems like CARB isn't tightening up their pass/fail parameters just yet.

Pics of the car?
 
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I have never lived anywhere that even does smog testing, But you passed I wouldn't worry about it.
 
MSD Blaster 2 coil - Great coil & cheap, and comes with a CARB decal, too.

I've even found them at Pick-n-pull
 
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