i have an 88 fc3c that im having trouble passing smog with, the car sat for about 8 months while i was at basic training and tech school, when i came back, i replaced thermostat, plugs, wires, oil and filter, cleaned my k&n, and it failed smog. i replaced the 02 sensor, and the main cat and it failed, but just slightly. then it developed an exhaust leak near the header and the smog numbers jumped up a little. i just ordered a replacement pre cat and i am going to fix the exhaust leak, my smog tech told me that its running rich... am i on the right track for sucess? also, when i hold the revs on the engine, it pops occasionally like its misfiring.

 

Step one: Compression check. Lower compression means an incomplete burn of fuel. There are several other things, but I recommend finding out if the base engine is good before continuing on.

A quick search in the FAQ will yield results of how to do it on a rotary.

 

i dont think that the compression is low, the car pulls as strong as the first day i got it.

 

you have to check the air control valve (ACV), to make sure its working PROPERLY. the air pump and ACV are very important to how the car performs on an emissions test.

 

That's exactly why it'sone of the most overlooked issues. If you want other answers, that's fine, but don't rule anything out until you've gotten it pinned.

Spark plugs, wires, ect sensor, AFM, intake air temp sensor, dirty injectors, clogged cats, O2 sensor, variable resistor, air pump, air control valve, egr... the list goes on.

 

i have had this car for 6 years, and it has less than 150,000 miles. the last two smog checks passed with almost no emissions, and i had never changed any of the cats. i will be performing a compression test, but the last one that i did roughly 15000 miles ago yielded compression readings that were still strong.

 

You will be surprised how much a GOOD working cat with no exhaust leaks will do to improve your emissions numbers. After testing and fixing nearly everything in the emissions system on my car, it was still failing miserably. So i replaced the cat and had it welded on so there were for sure no leaks. Took it immediately to the smog shop, not even 4 miles away. The car passed with flying colors.

But first, look in the fsm and test your emissions system per fsm specs. Not as hard as it sounds once you actually get in and start doing it.

good luck

 

Move to Oregon [or anywhere that does NOT have ****-DEQ] plug the airpump directly into the split air pipe and put 2 bottles of isoheet into 1/4-1/8th tank of gas, win. XD

 

make sure the Air Control Valve works, trust me. i've lived in CA my whole life, my Rx7 is cleaner than my moms mercedes.

 

^
Agreed. If it isnt, hit me up. I have a KNOWN working one off my old engine you can have for cheap.

 

Did you watch him do the test? How long did he warm up the cat for? Law says 2 minutes at 2500 rpm either rolling or stationary.

Also can you post your smog test results please? Was this an ASM (dyno driven test) or TSI (stationary idle test). Heck if you can just scan the result sheet that would be great and help me out a lot.

But like everyone else has said so far make sure your airpump is working as intended that is the #1 failed reason for FCs to fail smog.