i been having whats seems like an endless battle with cali emission testing. i have started numerous threads on it as well. With no mechanics who work on rotaries i was forced to go in myself and start sorting **** out. i figured since i've done all the tune up stuff (O2 sensor, plugs, wires,etc) i might as well check the fuel system and what i found was really shocking.

i found three injectors of the 195500-1370 (tan in color, look at pics) which according to the FAQ sections should be the correct ones for my 87 RX7 turbo which was manufactured in late 86. however what was really retarded and stupid was that i found a red top 195500-1350 injector on the primary injectors rail. . the question is, how would having this injector affect the performance of my car?

and could this be the reason why my car is running rich and making me fail emissions????

any help is appreciated

 

Uh, a red top 195500-1350 injector is 460cc. If anything you're running lean.

 

yeah that was my original assumption, but the fact that im still running super rich is still there. trying to narrow it down, i dont have flooding issues but i think i might have leaky injectors

 

How do you know it's running rich? Are you basing it off of high hydrocarbon levels on your emissions test? If that's the case, you should also consider the condition of the main cat and whether the split air solenoid is functional.

 

The Split Air Solenoid only open when you select fifth gear. See FSM. When you select fifth/over the top gear/ you put a ground on the Split Air Solenoid.

 

That would mean the split air path is closed off at all times except when in 5th gear. The default position for the split air solenoid has to be open, then when you shift to 5th, the applied ground closes the path off to the main cat. Either way, you're right in that it doesn't matter for emissions.

Operation of the relief and switching solenoids should still be considered since they could potentially keep air from flowing properly to the port air and split air tracts. Without vacuum to the relief valve, all air will just get dumped to the air silencer.

 

No. The poppet of the split air solenoid when de-energized, closesoff the path of airpump air to the split air pipe to the converter.

If you have a series four car, just remove the solenoid from the ACV with its poppet valve. Then key to ON and put the transmission in fifth gear. The poppet will be pulled into the body of the solenoid.

In fact, if you ever do remove the Split air Solenoid, it's best to put the key to ON and the car in fifth gear. Then unscrew the solenod. You do that so you don't chance losing the small spring on the poppet valve. The poppet valve and spring will be attracted to the solenoid body and won't fall down on the ground or in some spot in the fender where you'll never find it again.

Airpump air goes to the EXHAUST PORTS most of the time. Like at idle and certain road speeds. It does NOT go to the converter thru the split air pipe MOST of the time. It does this mostly because the afr on a NORMAL RX, is RICH at idle. The converter is most efficient at a afr of approx 14.7afr. So the airpump air mixed AT the exhaust ports, causes that RICH mixture (say 13afr) to be diluted to a leaner mixture prior to going into the conveter. That mixture is close to 14- 16 afr in what I've seen on stock car.

Actually, the jpg you attached is for a non turbo. His is a turbo. His works more or less the same, except the Relief valve in the ACV is operated by airpump Pressure and the lack of pressure thru the Relief solenoid, is what keeps the air from being dumped overboard. The Relief solenoid is configured opposite that of a non turbo Relief solenoid and prevents air pressure from flowing from one side of that solenoid to the other, even if it is energized.

 

.

 

Alright, so both the S4 & S5 FSMs and S4 training manual are vague on this subject, but it appears that if the split air solenoid does completely block off the split air tract when de-energized, then it DOES open in gears other than 5th when under LOAD conditions. What the solenoid does at idle means little since almost all emissions tests are done at 15/25mph.

The S4 training manual states that air is pumped to the main cat under "general conditions" (steady speed @ 1200 - 3600rpm?) for 120 seconds. There's no mention of the car needing to be in 5th gear for this to happen.

Then there's the S5 FSM. Assuming the secondary air injection system works in much the same way as S4s, split air injection is listed as taking place under MEDIUM LOAD w/ a warm engine. Again, no mention on this being in 5th gear only.

 

And here's how life is: you start up you car. You start driving. You step on the pedal pretty far because you accelerating. The RELIEF solenoid stays energized preventing air being dumped overboard. When you step on that pedal, that much, the Switching Solenoid becomes energized.

Now both are energized. So now the air can go to the split air pipe. So now your crusing along at a steady 40mph in a 35mph zone. You let off the pedal where the narrow range TPS is now below 55%. The Switching solenoid gets de-energized and shuts off the air path to the split air pipe i.e. no air to the converter.

Or another scenario: your driving along off a out ramp to the fwy. You get up to 70 mph and shift into fifth. Now both Relief and Switching are energized and air is blowing into the split air pipe. THEN you drive like this for approx 120 seconds and.........the Relief solenoid is de-energized and no air goes to the split air pipe, fifth gear or no fifth gear.

Or another scenario: your at emissions inspection. The dude gets in the car on the rollers. He follow a computer screen that tells him to advance to 15mph. So, initially the air goes to the split air pipe as he pushes the pedal to achieve that speed , the switching solenoid energizes, and air goes to the split air pipe.........but then he MAINTAINS 15mph by letting up on the pedal. As soon as the TPS gets to under 55%......the switching solenoid de-energizes and now there's no air going to the split air pipe. So.....during this part of the test there's virtually no air going to the converter thru the split air pipe.

Now the computer tells him to advance to 25mph. Same ole same ole. Both Relief and Switching solenoids are energized and that causes air to go to the split air pipe. Once he reaches 25mph he lets up on the pedal and the TPS goes under 55% once more and the Switching solenoid gets de-energized resulting in no air to the split air pipe once more, and he holds the pedal to stabalize at 25mph with no air to the split air pipe.

When he does the 15 or 25mph test, he MIGHT have to press the pedal if the mph falls, and then again the swtiching solenoid energizes and the split air pipe once again gets a puff of air til he lets up a bit and the Switching soleniod de-energizes.

Or say your driving along and get on the gas. Rpms go over 3800rpm. No air to the split air pipe even if the Switching solenoid is energized , because the Relief just got de-energized and is dumping the air overboard.

Then again, sometime the Relief solenoid de-energizes and dumps the airpump air at other rpms. I figure this has something to do with the MAP pressure plus rpm and TPS range. Got me. It happens and there's no real way for me to figure out how/why.

Some of the above I know from running two LED lights from the TPS connector and watching the lights come and go. The rest of it I know from cutting the split air pipe a few inches from the intake manifold and putting a piece of hose on it and running it into the cabin, and long enough for me to hold it up to my face and listen and feel the air from the split air pipe and at the same time watchig the two LED lights.

Then some I learned from having a ACV in my lap and applying vaccum and or pressure with a MITTYVAC and blowing into the nipple the airpump hose connects to it.

I don't deny that air from the pump goes into the split air pipe. But that does not happen all the time while driving and in my most humble opinion, not even half the time. Much less than half. Depends.

Turbo and non turbo work slightly differently. Non turbo strictly uses vacuum and the turbo uses vacuum and air pressure. Plus the coming and going of the Relief and Switching solenoids is different.

Anyway, you can be in fifth, the Split air solenoid energized, and have zip air going to the converter. Sometimes you do, sometimes you don't. Mostly no air if you've been driving and in fifth over a couple of minutes. Opps, ran out of space...

 

Lots of good info in there. Thanks for adding that. Though I think you might have a little too much fun playing with the systems on these cars . Hopefully shadow7 is actually having an emissions system issue so all of this ACV info is relevant.

One thing I'm still wondering about is whether the JDM ACV pumps air to the cat more often than a US version (no split air solenoid). My motor is mostly a S4 J-spec turbo, and at the moment I've got the opening for the split air pipe open to atmosphere. At low throttle / low load, under 3,500 rpm, I can hear what sounds like air pumping out the opening. This is under slight acceleration AND when I hold my speed constant. I haven't had much time to mess with it, but I plan on testing it some more to see when exactly it's allowing split air flow.

More than likely, it'll make little difference since the switching valve does the majority of the air routing, but it would seem that the main cat would run a little hotter at times than with a US ACV. Any chance you've messed with a JDM one? The internal paths are clearly different since the relief path comes out in a completely different spot.

 

hailers and rotaryrocket88, thanks for taking the time to educate me on my car, thats a lot of info mentioned i have to carefully read. basically yes i am relying on the fact that my car is not massing emissions because of the high Hydro carbons. not only that but the car has very poor gas milage and stinks like raw gas to the point where it makes me dizzy just standing by it while it iddles. it has only flooded three times in one year, compression is excellent, all tune-up components have been replaced and the ACV and solenids seem to be working correctly.

me and twofer where wondering how my car never blew because of running a smaller injector. like rotaryrocket88 said if anything i should have been running lean. so the theory went something like this.

since the 460cc injector was pumping less fuel im assuming the Computer picked up on this thus making the car's fuel system run richer. this along with possuible leaky injectors might be making me run rich.

the only othet two similar situations i've searched on here, one individual ended going with an Rtech computer and a little tunning and the other individual found out he had GSL-SE injectors in his car. both cars were N/A's.

basically im just going to go ahead and buy the injector im missing which i have to get anyways and then have them all sent to RC engineering for cleaning and all that stuff, then put them in there while i also check for any additional vacumm leaks and see where that takes me.

as far as my next emission test i will hook up the air pump directly to the cat.

if you guys think of anything else please share

 

The Split air solenoid just adds additional air to the split air pipe when the switching solenoid is de-energized and your in fifth gear. It's much like the Port Air Solenoid. Adds additional air to the exhaust ports at a given time.

It's too hard to tell what is wrong with that car. Injector needs replacing. The converter is Probably trash. I doubt the ACV is working right. My predjudice.

 

The ECU would have been running the 460cc injector as if it were a 550cc; so 17% less fuel from that primary. The only time the ECU would take O2 sensor data into consideration would be when you're cruising in closed loop. Under all other conditions, the ECU has no air/fuel input.

I still say check the cat. How old is it? You could have some fused sections that are limiting the usable surface area.

 

yeah i know my car is really screwed up, been struggling with it since i bought it last year, the cat i bought was a bonez high flow and it would be less than 4 months but since people kept insisting on me to buy a new one i bought two high performance ones and had the local muffler shop weld them in so now im running two cats.

as far as the ACV goes it seems to be working last time i checked but that wont matter since i'll be bypassing it next emission test

im not sure what you mean (i'm a newb)

so you are saying that the 460cc injector is able to perform as a 550cc.

i also forgot to mention that the impedance on the 460cc injector is high and the other 3 are low. dont know if that helps any much

 

No, the 460cc was getting the same input from the ECU as the other 550cc primary. The ECU has no way of knowing how large/small your injectors are, so it would have been sending too little fuel through that 460.

As far as whether a cat is bad or not: The inside of it looks like a metal honeycomb. If the cat overheats, the metal will melt and fuse some of the holes together. This restricts exhaust flow, and reduces the efficiency of the cat.

 

Just nitpicking and talking series four: The split air solenoid is only controlled by putting the lever in fifth gear. Nothing else. The jpg of the input/output page in the FSM is screwy and wrong headed. Which is proven by looking at the diagram plus looking at the operation of the Split Air Solenoid in the same section of the manual.

If the gear is anything but fifth, then the voltage should be approx 12vdc on pin 1I. If the gear is fifth, then the voltage on 1I should be less than two volts dc.

The gnd on 1I does not effect the split air solenoid. It probably does effect the operation of the relief and or switching solenoids in some fashion.

 

So I pulled apart a S4 NA ACV and took a look at the paths. Posted a picture below. The red path is split air, and the yellow is port air. The main opening that leads to the split air pipe is 3/16" (this is where the solenoid plunger seals), BUT there's a second smaller hole (1/16") where I have the left hand red arrow. This opening never gets sealed off by the split air solenoid.

So, this makes things simpler:

If the the switching valve is open (vacuum applied), all air goes to the port air path.

If the the switching valve is closed, all air goes to the split air path and flows through the 1/16" opening.

If the the switching valve is closed & the split air solenoid is energized (5th gear), all air goes to the split air path and flows through both the 3/16" and 1/16" openings.

So for the cases where the switching valve is closed, there is always air going to the main cat. It's just much more restricted than when the split air solenoid is energized. There's 10x more area with both open, but the pressures will be higher with only the 1/16".

This all makes me wonder how large the opening is on my J-spec ACV. If the path is always open, it's likely that there's just the small 1/16" opening. It Doesn't really matter, but still curious. Maybe I'll take it apart sometime too.

 

is this the same for the turbo model rotaryrocket88?????

 

I don't have a US-spec turbo ACV to take apart, but I don't see any reason it would work any differently. Slight differences, but they're made to do the same job.