Just wondering if a stock FC T2 would pass smog if my precat, main cat and o2 are new?
I changed my 600cc primary injectors back to 550cc ones remanufacturered by TLF Performance.
my turbo barely spools and I think I have a small leak by the manifold.
any other things to check to reduce the richness?
anyone here with a stock FC that passes smog? Trying to see if it’s possible before I spend even more $ and time on this car. Thanks 🙏 so much.

 

A little trick not often used or known about, the AFM does have a tamper proof cap on it that can be drilled and popped out so you can tune the AFM and fuel mixtures. However you should screw the pilot needle in and count the turns before messing with an AFM and write the default screw setting on the AFM for future use, i would only use this as a last resort to try and bypass spending countless hours trying to figure out why the fuel mixture won't meet emissions.

the TII has LOTS of places to leak air in the intake, TID cracks, leaky old seals on the throttle body, dry rotted injector seals not shimmed just right... to name a few. a smoke tester would come in handy on these cars.

Turbo spooling issues could indicate you have a large leak somewhere that you aren't seeing.

when i would smog cars i would use my nose before bothering with a test facility, if i can't breathe near the exhaust without choking or my eyes burning you have zero chance of passing smog. good high quality cats(Bonez or OEM) and working air injection systems are a must.

other reasons not so easy to spot too are fuel pressure or internal leaks, a leaky FPR can dump fuel into an intake runner and cause one rotor to run rich, other cases like Walbro 255LPH pumps or higher volume ones overtaking the FPR and pushing too much fuel pressure causing an overly rich issue to develop.

I would consider the turbo spooling issue to be the biggest indicator though, likely telling you to press harder to look for intake leaks.

Other less likely issues are the timing is just wayyy off, i have seen engines rebuilt with mismatched front pulleys where timing was retarded by over 25 degrees. the only way to verify this is with a known good matched pulley set, or having yours sent off to be verified by me or someone else who has a proper TDC jig. aftermarket pulley sets from reputable shops like mazdatrix or Atkins should have TDC properly labeled, but not the 5/20ATDC marks we are used to(you can make your own based off the marks they have existing). timing can also only be set if the engine audibly sounds like it drops into idle mode and running smoothly below 800 RPMs, you can hear a difference from just off idle to idle timing mode. the idle should abruptly drop almost 200 RPMs below 1000 and into a much deeper sound. the eccentric shaft keyway for the pulley should line up directly at 9 o'clock to the block deck to be at TDC, this is a rough way to tell if the pulley is very far off.

 

+1 its possible. if you haven't the air injection control valve (ACV) needs to work.

we checked my old T2 once, with no air pump and no cats it was ~5500hc's
adding the air pump brought it to ~1900hc's
and putting the cats on it ~180hc's, which was enough to easily pass at the time.

 

when i lived in nevada i didn't even use the ACV, i ran my smog pump directly to the main cat inlet port, worked like a charm, at least to get the car to pass but nevada doesn't care how you get the car to pass, so long as it meets the HC/CO/NOX limits, the smog tech actually let me tune my car with my microtech handheld tuner while we ran the test. it was in fact running too lean and i had to fatten the trims up, a common misconception that unburnt hydrocarbons is always a rich mixture.

as far as i recall the stock setup doesn't inject air until 3500RPMs, which is outside california smog testing perameters(which is honestly why i don't know a ton about its function), you likely could modify the ACV to inject air earlier or all the time during testing procedures. i never messed with the ACV so i can't even speculate as to how you could accomplish it, likely it's as simple as putting vacuum to that ACV diaphragm port or removing it from the bypass diaphragm which dumps unused air to atmosphere.

injecting air all the time especially at idle isn't great for the cat, so consider it just a recommendation for smog testing purposes. also consider there is a air check valve in the ACV to prevent damage to the air pump during backfires and excessive backpressure in the exhaust.

 

The stock setup does "Port Air" form idle to ~3500rpm which is the exhaust ports.
it works great.

 

right, it has been a while since i had to deal with all the stock emissions stuff. glad florida has zero of any of it, lol.

for reference though in nevada i only plumbed air to the main cat and it passed rather easily. once the test was done the smog pump came right back off. the car had no precat either, just a Bonez main cat. Nevada has similar limits as california though they are a little more lenient in the numbers.

FCs in general run either rather clean or really dirty, i have seen them run 3HC on the machine and other times peg the machine at 1500+. smog techs can get quite annoyed when the latter occurs because it can clog the sniffer, resulting in a whole lot of maintenance required to get the machine operational again.

 

Not spooling points to a leak in the intake tract. I had a 88 TII that a crack in the elbow back at the firewall from the turbo to the IC. I didn't know it was there but the guy I sold it to did. It ran fine, except every once in a while it went down on power and wouldn't idle, or hunt wildly. It did pass emissions in Texas, though.

Chase the entire intake tract for cracks in the rubberized tubing and connections.

You don't mention what the readings are, or what they'er supposed to be, but I'd always change the oil in our RX fleet before inspections. Never sure it helped, but couldn't hurt, since the engine does purposely use some oil. Fuel in the oil can affect emissions.

What do the plugs look like? Just some thinking out loud here.

 

First off, get a smog report even if you have to fail to get it. . . .. . .It will tell you what you are dealing with.

Rich mostly means high carbon monoxide although you can have high hydrocarbons as well. Failing with high carbon monoxide means you should add denature alcohol 1:10 prior to testing. The goal is to raise the O2 content to convert to Co to Co2

I would change the water temp sensor behind the alternator (I assume you have one on a S5) and new spark plugs.

Definitely change back to 550's. . . .Surprised you only have 2 cats. . . .Mine has three.

Here's my 86 non turbo from CA couple years back.

 

My HC was 154 and 402 for 15mph and 25mph respectively (max allowed is 85 and 67) . Also CO was 0.32 and 4.80 ( max allowed is 0.54 and 0.45).
something is wrong with my car to run so rich. Maybe one of the sensors or air systems not working or leaking?

thanks for the info and proof a FC can pass smog here 🙏. It gives me hope.