Thread: Calling all engine experts - Smog from hell

Do what andreas said, HC is a result of poor combustion which means ignition issues.

somebody else also mentioned opening spark plug gap, try doing that and also replacing ignition components that are old. test the plug wires to see if resistance is out of spec.

Told Dala that in chat yesterday. That is an unhealthy combustion chamber judging from just the plugs alone.

Here is what I tell customers in other states that have emissions problems in the USA.

1. Get a 00 to 02 P11 cat from a roller rocker motor. It comes with a cat in the header. The cat up close to the head burns hotter and cleaner. If that does not work then

2. MSD ignition and coil 90% of the time will clean up the situation.

never ever had to go past these 2 steps.

lastly as said before aftermarket cats suck ass

What do they look like to you? I'm not very good at reading spark plugs.

All the peppering is too much heat, detonation, and/or a dirty chamber. My B14 plugs looked just like that when I was running too much timing, with incorrect t-stat, and my ignition system was plagued by loss. I had moisture corrupting the signal from the distributor to the wires to the plugs. Huge mess, but those plugs he posted looks similar to mine. Maybe I have them somewhere....



Left side are good B14 plugs. Right side are my fucked up bad ones. This is on an car with a JWT ECU and normal bolt-ons. I had too much timing and a dirty combustion chamber caused by weak ignition. Cleared all problems once I fixed the ignition system using OEM parts and some common sense. New spark plug gaskets, new plugs, di-electric grease on all contact parts, problem solved.



Mine were FAR FAR worse than Dalas but I see similarities. Sadly, I do not know how to fix it electronically via ECU/NEMU/god knows what.

Close ups.

Dala's plugs look fine, and these ^^^^ don't look too bad. Light gray or brown is good and the electrodes aren't worn. Definitely more deposits on these though.

Noted. Coil-On-Plug is coming this week. See further down.



Passed previous year with it, cleanest the car has even been. Running decat previously, so this cat has only been used for smog tests. It looks so clean you would be able to eat from it. Higly doubt it.



I actually checked for vaccuum leaks just out of curiosity. I pressurized the manifold like this:


No leaks were found.

By the way, vacuum leaks on this car wouldn't do much. It is running a MAP-sensor, so its a speed density type tune. I get 250mbar absolute pressure, same as the car always has had. I know this is a healty value, my friends SR20VET got 240mbar abs press. at idle too.
High HC is definately unburned fuel. I'm beginning to think spark is to blame. See next post.



-Spark plug wire resistance is within spec. I have 3x sets of wires, am currently using the freshest least resistance ones.
-Spark looks weak? see this youtube video:



I plugges the sparkplug directly to the coil, and spun the dizzy by hand.

Next order of business is to test a COP, and see how strong the spark is with one of those.

Passed previous year with it, cleanest the car has even been. Running decat previously, so this cat has only been used for smog tests. It looks so clean you would be able to eat from it. Higly doubt it.

Experts say aftermarket cats are usually good for 1 test, couplemonths ago i helped a buddy with one of those cats took it off and it was completely clogged all the insides were falling off clogging the entire pipe we were able to clean it up and only pieces of what it looked like charcoal came out of it , hence showing the quality of this things , i would recommend if available to try an oem one ,the 1st run you did was pretty close of passing what ever you did after that you made things worse,

The first test was close to passing due to huge exhaust leak after cat. All the bad emissions escaping, introducing fresh air drawn into the system.

Finland is a very strict nation when it comes to emissions. Kinda like California you guys have? They don't allow cheap branded cats to be sold in stores just for the reason you listed. I paid 250$ for that cat. You can buy a "universal" Euro3-certified cat for 125$, without flanges, but I wouldn't bother. The cat i have on it now should easily pass Euro 4 all the way to 6.

Anyways, you can really hear the engine being rough. New cat or multiple cats would only be a bandaid solution. I am certain once the cause of the rough running is found, excessive emissions will go away with it.

Also thinking about purchasing an exhaust sniffer. Once the valid katsastus-time runs out in 10 days, I will no longer be able to drive the car. Will check prices on monday..

I haven't read the entire thread, an no doubt you're getting good advise from people with way more experience than me (it's been 13 years since I had to deal with emissions tests) but isn't the O₂% (Oxygen percentage) too low in all of your tests, which indicates a rich mixture, which could explain your high HydroCarbon readings?
You then went and added larger injectors and made it worse (even with retuning) because the atomization no doubt is worse on larger injectors and then added even larger injectors which made it just as bad (even with the retuning). HydroCarbon readings are basically gasoline readings, right? Unburnt fuel?

I'd be curious what you'd see if you went to the place you went to do some testing and instead of messing around with the timing so much if you got those AFRs in check. Raising the base fuel pressure could help with atomization as well. But frankly I'd be trying with the smallest injectors I could.

Apologies if I'm not making sense. I don't have much experience here.

Edit: I see lots of talk about poor ignition causing high HC. That makes total sense to me, since that too would cause unburnt fuel to pass through to the exhaust. However, I think the low O₂ readings are telling a different story. If the ignition were bad, I'd think you'd see high O₂% and high HC... But since you're seeing very low O₂% and high HC I would think the fueling is the issue, not the ignition.