Originally Posted by rcefstsfecr
^^^ what is the link to that FSM?
I don't want to buy a shop manual for my car, is there a place where I can still find out the information from one Shop manuals for both series can be found on-line at: http://www.cochran-racing.com/FSM/index.html http://slackerware.dynu.com/fsm/ http://208.62.166.66:82/guest/shop_manuals/ or (86-88) http://www.teamfc3s.org/main/factor...nual/1986_1988/ and (89-91) http://www.teamfc3s.org/main/factor...nual/1989_1991/ |
dDub -
Just tried the air rig and dropped my HC's from about 550 ppm to 8 ppm on the high rpm test for a few minutes work and a few dollars. Still failed by a little on the low rpm test for CO but by now I've spent the requisite amount of money and shown enough improvement to qualify for a waiver. I didn't try to lean it out so that might have gotten the CO down enough. Now I have all year to figure out what is blocking the air to the cat in the first place. BTW - the emissions guy seemed to at least know a little about rotaries. Wonders never cease Thanks much! |
HI,
There's a good write up on the emissions system here: http://www.geocities.com/huguesdc1/index.html Read the section on secondary air injection. Basically what Ddub has done is bypassed the Air Control Valve (ACV) so that split air is always being delivered to the cat. This is actually one of modes in which the ACV is supposed to operate. Car warm, medium load, the ACV should be sending air to the cat. These are the same conditions under which the 15 and 25 mph testd are done. If you have a bad ACV or vacuum leak or bad solenoid valves the air to cat trick will help. If you have another problem say a bad set of oil control rings and you're blowing white smoke like a pope was just elected, this most likely will not help. I had a dead cat and couldn't pass even with the air being sent directly to the cat and denatured in the tank. I checked TPS, timing and searched for vacuum leaks and replaced the O2 sensor and plugs before breaking down and buying a new cat. My results after the new cat with everything else legit: @ 15mph, limit reading , @25 mph limit reading HC PPM 135, 2 , 130, 1 CO% .76, 0, .8 , 0 NO PPM 1052, 850 957, 164 The problem with emissions troubleshooting is that without specialized equipment to quantify what's coming out the back, you can't tell if your tweeks are helping or hurting. If you start throwing money at the problem and just replace things that aren't broke you're wasting your money. |
Originally Posted by gordonrick
dDub -
Just tried the air rig and dropped my HC's from about 550 ppm to 8 ppm on the high rpm test for a few minutes work and a few dollars. Still failed by a little on the low rpm test for CO but by now I've spent the requisite amount of money and shown enough improvement to qualify for a waiver. I didn't try to lean it out so that might have gotten the CO down enough. Now I have all year to figure out what is blocking the air to the cat in the first place. BTW - the emissions guy seemed to at least know a little about rotaries. Wonders never cease Thanks much! |
Yea I wish i could install my air pump again. I took it out since I installed my new turbo. It will not fit back on now. I failed before, becuase I had only one cat on.
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That sucks. You should get an electric pump maybe from a different car then and just mount it wherever you can fit it. That should work similarly.
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Originally Posted by TKE
Why do you people spend so much time money and effort on passing emissions?
In my neck of the woods, you just find a run down looking shop in a shady neighborhood and slip the guy 50 bucks problem solved. You can tell by his emissions numbers he has oxidized nearly all the CO (partially burned fuel from a rich mixture) into CO2, but the HC are still high due to the oil burning nature of the rotary. Since there is no O2 number like I'm used to seeing it's hard to say if there is too much air. Many states have an O2 limit as well so one might have to bypass some of the air from the air pump to get the balance right. What kills cats is misfiring. Dump a lot of unburned fuel and air into the cat and it will burn and burn up the cat. The extra air is only going to be a problem for the cat if there is a lot of extra unburned fuel. |
Originally Posted by Marcus_F
No visual? If an S5 with the orignal zillion mile cat is failing with high HC, it can pass by retarding the timing. That's one of the oldest tricks out there. It will increase NOx, but S5's usually have a ton of leeway as far as NOx. I don't know about NOx and S4's, but it's worth a try.
For those wondering about catalytic converters, Rotary News has an article about Rx-7's and high flow converters in the archive. Also, MazdaSport ran a similar article. |
Originally Posted by RoadRaceJosh
Retarding the timing acually lowers NOX as it reduces the peak combustion temperatures that form NOX, but helps light off a cat as it leaves more heat in the exhaust gas. Rotaries don't have a problem with cold exhaust so this trick probably won't get you very far with an RX. With the high surface area of the rotary combustion chamber (lots of relatively cold metal) HC is much more of a problem than NOX. EGR is strictly to reduce NOX as it dilutes the mixture with inert gas so it burns more slowly and has a lower peak temperature. Diesels are hell for NOX due to the high combustion pressures and temperatures involved which is why the new stuff is coming out with cooled EGR. Heck, even GM 5.7 diesels had EGR.
This isn’t theoretical, I’ve done it. I t took five passes through a California Test Only station before I could get my last smog certificate. Retard the timing on an S5 NA and the sniffer will show that the HC levels have fallen and the NOx will increase. Lastly, I specifically said an S5. S5’s don’t have an EGR. |
I could've sworn that advancing timing creates higher EGT's, not retarding...
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