Ok, just pulled the air filters out of rx7_lovers car. Top filter did not look that bad, but the bottom filter was horrible. Even after taking out the leaves and brush that was lodged in the filter, banging it around a couple of times, still could not see any light coming through the element. Going to start with cleaning the air filters, changing the oil tomorrow and getting the stock cat changed and put back on the car. Any suggestions on what type of plugs to get and what the gap should be at? I will be taking another trip to the auto parts store tomorrow after talking to the muffler guy about a cat. I will let you all know what we find out this weekend when we go to retest again.

 

Also, when I was driving the car for that past couple of days, started to feel it bucking when just at part throttle while crusing on the streets or freeway. Not sure if this means anything until after we change the plugs and oil, but could have some meanings. When on boost, or off throttle completely, car runs great, but still dies when cold and rpms drop when reving or coming to a stop.

 

Get the stock plugs (stock heat range). No gapping necessary, as they're surface-gap plugs.

I still think he needs to pull back on his fuel curve on low rpm/throttle settings.

 

I downloaded the PFC manual and also found a map from someone with similar mods. If we cannot get a decent smog with new stock plugs, then I will definitely play with the maps. Your advice is very helpful. Lets see what happens in the next couple of days.

 

Ok, we changed the plugs, oil, cleaned the air filters. Ran 1 gallon of alcohol in an almost empty tank. Put 2 gallons on top. Car started to sputter. Two more gallons of gas, and car smelled clean. Numbers were looking good. CO = low. NO = low. HC = not bad, but still not low enough to pass. Next weekend we are going to put the stock downpipe on and have a new cat put in. Right after that, we are back to the smog ****'s.

Ok, since the car has had the new vacuum hoses in, it is starting to buck and miss at crusing and light throttle. The O2 sensor has been replaced about 2k or 3k miles ago. After the alcohol, the bucking/sputtering has got worse. When the car is coming closer to boost, it runs smooth. The car starts and idles great, but sometimes when it is cold, it stumbles when first step on the gas. I noticed that in the daytime when the headlights are not on, the car runs great. but when the lights are on at night, the car stumbles at light throttle. rx7_lover has told me that there might be some ground wires missing. I am going to look into running some new ground wires. Any other ideas for me to look at? TIA

 

Hey guys, one of the guys at KD Rotary was telling me that Tri-point engineering makes an aftermarket downpipe with a hi-flow pre-cat that is CARB certified. I wish I had a website or something, but I hope this helps.

 

Tri-Point:
http://silverstone.fortunecity.com/brabham/261/

They do have a hi-flow pre-cat, but maybe I shouldn't pass on links to companies in California, seeing as I'm not actually from there...

 

Don't mess with the precat (including the TriPoint unit). Just put the stock main cat back on, and then deal with the air/fuel issue you have. The supposed electrical issue can be cooler air at night affecting the a/f. The fact that you have a PFC complicates things somewhat, as its complete adjustability means you must have everything in order (including installation). You need to get your PFC maps sorted first.

 

On tri points website it states that "carb applied for" it doesnt state that its carb legeal. You say the air pump works but do you know if the air is getting to the cat. What does you o2 reading say. I think mines say 5 or 8% at high speed. With the car cold, disconnect the air hose going to the cat. Start the car, there should not be any air going to the cat. After about one minute the acv should send air to the cat. Make sure the diverter valve on the cat is working. Rev the car to like 2500 rpm and there should not be any exhaust comming out from the diverter valve. With the car idling there should not be any air comming out of the bypass hose from the acv. Put back the stock precat and a known good factory cat. I dont care what people say about the aftermarked hi flow cat or down pipe passing smog.
With the ca enhance dyno smog you would want the best cat money can buy and that would be a good functioning original mazda cat.

 

Oh yeah, most of what i said is an indirect way of testing the acv. That is like the most important part of the emissions control system. The air pump pumps air, the cat cleans up the emissions. But with a bad acv you will never pass smog. At idle my car with a bad acv read 2000 hcs.

 

finally the info ive been searching for! thanks rx7will.

btw, what do you mean by '5 or 8% at high speed'? inj. duty cycle? O2 volt reading? if you were talking about the O2 volt, i hit about 1.25V around 2700~3000 rpm (PFC reading).

 

on the smog print out, there should be a section that list o2(oxygen) content, its usually in a percentage. Make sure that you have about 5-8 % 02 content reading. The higher the car goes the more 02 the cat should get, until the air pump turns off that is.