dlarson101

I'm having problems passing smog here in CA. I have all the smog stuff still conected(except precat). I have a Bonez DP, Tri-point Cat and RB dual tip. My air pump is running at the correct RPM's. I also have clean air filter, new oil, plugs, PCV, plug wires, O2 sensor, ACV and new fuel filter. My vacuum hoses are new viton ones and boost is normal. I am still running the stock ECU.

How much of a roll does the coolant temp sensor play in fuel?

Is there any thing else I can check?

dlarson101

I have serched, but can't find too much about how this would effect the richness.

I was talking to the smog guy and he said this might be a culprit. I don't know if his knowledge applies to an FD.

GSLSE20B

the coolant temp is one of the main reading points that is always in play ... if it is sending a signal saying the engine is cold your car will not enter closed loop mode .. the engine will stay running in a choke mode ..

GSLSE20B

what kind of numbers have you been getting ...

rotor rod

A bad coolant temp sensor can definitely cause an engine to run overly rich, the ecu will stay in open loop. I am not familiar with the FD or rotary engine though.

Early to mid 90's Toyota's will almost always throw a check engine light when the coolant temp sensor goes bad.

You don't have a check engine light on I take it?

rotor rod

Doh! I posted late.

dlarson101

I'm not getting any CEL codes.

I am passing the 15 MPH but not the 25MPH. I don't have the numbers with me, but the HC's are over the limit. I believe 25 MPH is 53 and mine is somewere around 90-100.

I think it is down to either my airpump or the h2o temp sensor. I have an air pump on the way(thanks GSLSE20B) and tomorrow I am going to check the sensor.

I couild put some denatured alcohol in, but I'm about to install a PFC and want to make sure everything is cool before I get a tune.

AHarada

iTrader: (25)

Yes, the coolant temp sensor would definitely affect emissions. Does your temp gauge in the gauge cluster move? I doubt you would pass 15 mph though with a bad CTS.

HC's indicate misfires, not running rich. Running rich would give you high CO numbers. Maybe you have a weak ignition coil or something?

dlarson101

My temp guage acts normal(for stock)...

You are the first person that has said High CO is running rich, and not the other way around.

It does backfire as if it were misfireing. I think I will check that as well. To do this do I just follow the FSM procedures or is there a better way?

Mahjik

iTrader: (1)

Just FYI, the ECU and the coolant gauge get their readings from two completely different sensors.

jeff p

is your car an auto?.. if so have the tech test the car in 1st gear until 15mph then shift to 2nd gear for the rest of the test. if the car goes into overdrive during the test you will fail. with the auto cars the ecu gets very rich in overdrive. I had this problem until the tech tested the car like I stated above and I passed fine.

Jeff

Sr20fd3st

yea high levels of hydrocarbons (HC) would mean that there is excess unburnt fuel in the exhaust. Gasoline is a mixture of like over 500 different hydrocarbons. HC's are things like Hectane, Isooctane, Benzene ( all of which are in gasoline).

Aharda was right, rich mixture will give you high CO, while misfire give you high HC's. But a very lean condition that results in a misfire can also lead to high HC's. a goofed up o2 sensor or a hardcore vac leak can make that happen, which you seem to have replaced already. If you're not throwing a code on that sensor I doubt it's the problem.

If that's a highflow cat your using it's pssible it may not be as effective as a factory unit, but i doubt it would have the effect you're having.
Throw some injector cleaner in your tank, sticky injectors or injectors where the seats are completley sealing between cycles can cause you to run rich.

dlarson101

Well It's not the CTS. I checked it and the readings are fine.

I also pulled the UIM and checked the coils, ACV and checked all the vac lines that I could get at and these are all good as well.

I believe it's down to the airpump... My AP failed and I had it rebuilt and I was a gross polutter. I found from a few reputable rotary shops that they have never heard of a rebuilt AP that would work properly. I bought a used one from the forum and it got me to just not pass. I have a different one on the way and will put it in Monday. I hope that it's going to pump enough air to burn the extra HC's.

Sr20fd3st

If you wanna get away with it real easy like, just lower your car so low that they cant fit it on the rollers. they wont put it on rollers if they fear it will damage somethign because they dont want to be liable. a buddy of mine did this with his car and it never would have passed but it sits about 3 inches off the ground so they just put a sniffer int eh tailpipe and he passed lol