smog troubles, 92 2.3L ranger

[MoToMaStR]

hey fellas, got a 1992 ranger XLT, 2.3L manual with 79k on it. Failed Komi-fornia smog test again today. I am only failing with hydro carbons (unburnt fuel) at the 15mph test. i am passing HC in the 25mph test (i am right on the limit but still passing). I have installed new plugs, wires, cleaned the Idle air control valve, cleaned MAF with proper CRC cleaner, new K&N air filter, fresh oil change and filter less than 100 miles ago, new O2 sensor. I can only guess maybe catalytic converter or coil packs? I repaired all previous codes (172 was o2 sensor), and i had code 341 because some ass-clown mechanic yanked out my octane adjustment pin and retarded my truck 4° and made it run like SHIT. anyhow, after plugging the shorting bar back in, truck runs great, ALL my power is back. I ran the code scanner again. i have code 1-1-1, SYSTEM PASS! I notice my exhaust still smells a little gasssy/rich, and i have an occasional hiccup where the RPM drops lower or stumbles for a split second every 30 seconds or so. any ideas? i am totally lost, im poor so i really dont want to take it to a komifornia ripoff artist turd shop; and get bent over for something i'm capable of repairing. so, again, the issue is (hydro carbons being about 3times higher then average) so i need to pinpoint WHY my HC is jacked up so high. Im guessing the coil packs are starting to give out if im getting the occasional hiccup? or clogged up cat (from my truck running in retarded mode getting 15mpg for a few thousand miles?) help me out guys!

 

[scotts90ranger]

You're overthinking things... the cat simply isn't warmed up when you are getting the test done. Drive it like you stole it on the way to being tested for at least 10 minutes, more if it's not warmed up yet, and go at a time where you don't have to sit and idle for more than a couple minutes

I'm not familiar with the chassis tests, do they just start you from a stop then go up in increments of speed? If so, that's screwed up, a cat isn't going to get to operation temperature by 15mph unless you warm it up beforehand

 

[MoToMaStR]

Well i ran the snot out of it up and down the freeway doing about 85 or 90mph for 20 miles then brought it in to the test station. The truck sat for about 20 minutes, then idles for 10mins while he "checks everything" under my hood. Then they put the probe in the tailpipe and start the rading at 15mph rolled on from a stop/idle. Then they take a reading at 25mph immediatly after the 15mph test. Minutes after that, he hands me a paper that says a failed. :/ but my concern is, why are only my HC so high? Everything else is well within the limits. Did soke more reading, now im thinking of two other things to check, injectors and EGR. So in order, what do you think? Clean/replace EGR, test/replace coil packs, inspect the injectors and lastly put on a new cat? Im lost man, i have to get this thing to pass before the 1st of november.

 

[wr250rdr]

I was at the limit for both tests when I took my 2.3 in and the guy failed me. Truck was running perfectly fine so I put in a new cat and got acceptable numbers.

 

[debogus]

compression check ?
These engines have a issue with exhaust valves.
Run a bunch of sea foam through it (in the oil, in the tank and through a vacuum line)


79K ? no roll over ,really

 

[MoToMaStR]

Hmmm, well im getting a slight hiccup at idle, every 20 or 30 seconds it skips a beat and the rpm falls/stumbles then catches itself right away. I did notice, at idle,... Me headpipe is around 355-365 degrees F and my cat under the heat sheild was barely making it to 200 degrees F (this is at idle) but when i rev the shit out of it to make some heat, both the cat and head pipe make it beyond 450 F which is the limit of my thermal reader) do you think the cat could cause that little hiccup and the rich smelling exhaust? I was wondering because im passing CO, and NOx tests, but just failing the 15mph test for HC. The coil packs are original 1992 ford parts, probably loaded with resistance robbing carbon due to their age. I have to test them today for ohms and will report back. Then im going to attack the EGR. Hopefully incan find a cheap shitty universal cat and weld it up myself.

 

[MoToMaStR]

compression check ?
These engines have a issue with exhaust valves.
Run a bunch of sea foam through it (in the oil, in the tank and through a vacuum line)


79K ? no roll over ,really

Yes, not rolled over. Youd believe it if you saw under the hood and under the truck. Cali truck so no rust, no moisture/weather beaten. All the rubber/trim is intact, interior is immaculate. Its a legit 79k, so i HIGHLY doubt its a compression issue. She fires right up on the first half second of a key crank. i know, hard to believe right? I picked it up for 3,000 about a year ago and it was running SUPER rich and sluggish. That octane adjustment pin was removed when i bought it, and it ran super weak due to the retarded timing from pin removal. Only god knows how long previous owner ran it in retard mode (pin removed) super rich, so maybe the cat is fried up? I will definatly look into that. I will check exhaust pressure before and after the cat today as well.

 

[MoToMaStR]

UPDATE
So i started tearing into my EGR valve today in hopes of cleaning it and bolting it back on. Thing was gunked up with rusty looking carbon, but the valve still operated and the diaphragm held vacuum relatively well. so after i cleaned it out and rinsed it out with CRC cleaner, i stuck my finger in back of the throttle body where the EGR bolts up. my finger tip came out goopy and wet, so i stuck a screw driver in there and felt ALOT of resistance. figured, theres no other way to clean that baby out then remove th TB and Intake manifold.
anyway, after 20 minutes of moving stuff and unbolting that sucker, and she was free, i shoved a larger screw driver through the hole and it was STUCK, had to tap it with a hammer to get it through. and out popped a cylinder of carbon which use to sit in that EGR tube. so i ran a 9mm pistol brush on a cleaning rod with my drill to bust out the rest of the stubborn gunk, and hosed it with Carb cleaner. bolted her back on and now she idles much smoother and lower rpm i think. still having that "hiccup missed rpm" every so often but i guess things are looking better...
now, do any of you think that would cause me to fail the 15mph HC test on smog? should i keep diggin for problems?

Today, cleaned EGR, throttle body and intake manifold, checked my coil packs for resistance. they all tested out ok, except the right side (intake manifold side) coil pack had tested about 1.5 (x1) ohms more resistance then all of the others. should this be a cause for concern? perhaps thats whats causing my stutter step on idle?
also, if they are of any help, here was my last smog test results (minus all of the work i put in today listed above)

15mph test | RPM 1640 | %CO2 MEAS 12.6 | %O2 MEAS 2.9 |
HC PPM |MAX 92|AVE 38|MEAS 114|
CO % |MAX 0.58|AVE 0.05|MEAS 0.09|
NO PPM |MAX 1043|AVE 352|MEAS 734|

25mph test | RPM 2604 | %CO2 MEAS 14.5 | %O2 MEAS 0.2 |
HC PPM |MAX 78|AVE 32|MEAS 78|
CO % |MAX 0.72|AVE 0.07|MEAS 0.09|
NO PPM |MAX 903|AVE 297|MEAS 687|

this test was run with my EGR passage way in the throttle body completely stuffed, sealed shut with carbon and goop.
what do you guys think?

 

[wr250rdr]

That could be a big issue you were having and should drop your carbon quite a bit

 

[MoToMaStR]

right on, im running a can of injector cleaner through a tank of gas right now for preventative maintenance. I think im going to replace the cat anyway, just to be sure that i dont fail smog again. Im pretty sure that EGR effects mainly/primarily the NOx which are already at an "acceptable" level. I am 22 points high on the hydro carbons, so im worried about that. HC has been the trouble area. Im willing to bet dollars to donuts, that since my truck has been running super rich for probably a REALLY long time, that original OEM ford cat from 1992 is completely cooked.
If i dont pass smog after installing a new catalytic converter, i will probably drive it out to the desert and set it on fire, lol hahah, do you guys suggest a direct replacement or the chop and weld style universal cats? both are about $110 bucks give or take online. i have a welder, but im scared that the flange bolts arent going to give, the old O2 sensor was a mother F'r to take out....

 

[shane96ranger]

One of these other I/M guys can straighten me out if I"m wrong, but I understand EGR to only have an effect on the NOx reading. And you're passing there. I would check for a vacuum leak. Also, take a reading off the fuel pressure regulator - it should be 39psi with the vacuum line unplugged (cap off the vacuum line with a little bolt or something). Those two things can go undetected by the ECU.

 

[wr250rdr]

I think I payed 140 out the door with the cat included to have a local muffler shop install, for the extra 30 bucks in my mind it was worth it to not hassle with it

 

[Mark_88]

My EGR was plugged at one time and when I cleaned it out my truck ran better and I also came closest to passing the emission test...failed by 25 or so on the hydrocarbons...but the EGR should, hypothetically, suck in everything that is in the exhaust and help burn off excess gas and reduce hydrocarbons in the process.

I think with a new cat and a clean EGR it should pass...and you may be able to help that a bit with some octane boost...supposed to burn cleaner than lower octane gas (hence the increase in products like Guaranteed To Pass which are, apparently, octane boosters).

Not sure...haven't actually passed an emission test with this Ranger...ever...and some part of Ontario have eliminated the test...thinking of moving to one of those areas...lol

 

[shane96ranger]

Thought of another thing.... any exhaust leaks will cause HC's to increase because of a false reading at the O2 sensor.

Here are a couple tips I found. Still doubt EGR has anything to do with it. Does the 2.3 have a smog pump? That could cause issues if it or it's fellow components weren't working properly.

http://www.smogtips.com/failed-high-hydrocarbons-HC.cfm

Sent from a Commodore 64 using a 300 baud modem

 

[MoToMaStR]

Hey thanks man. I went a bought a new cat and had a muffler shop weld me up today. also, I tore into the truck again today, had to yank the throttle body and upper intake manifold again to reach the PCV valve with my ogre hands. It was kinda sticky and boogered up. It didnt rattle very well when i shook it. Had a bunch of slime and cruddy carbon in it. So, aside from coil packs, everything has been done from top to bottom. I didnt test the FPR yet or yank the injectors but, i have a feeling that the PCV, EGR and new cat oughta take care of everything. Maybe after i pass, i will make a write up for the forum and one of the mods can make a sticky for us poor souls in california getting screwed with increasingly strict emissions laws. I know im not the only dude in this kind of situation, hopefully my pain and suffering could help out somebody thats having similat issues. thanks again man, going to smog test again tomorrow, 3rd time is a charm; ill post reaults after i pass.