This is about the 6PI actuators. They are governed by rpm and load and come on at 3800 if the rpm and load conditions are met.

I was wondering if you took the vacuum hose off the bottom of the pressure sensor and plugged the hose, and then rev'd the engine over 3800rpm, will the actuators open or not??

I figure if the secondary injectors will come on by plugging the vac hose to the pressure sensor and reving to above 3500 rpm, then the same might apply to the 6PI actuators.

I don't own a series five but have been curious if the above would work or not.

 

I've asked for someone to test if this works a couple of times without any response. This time hopefully...

And it's 3850rpm BTW.

 

Ok, yes. It's 3800rpm for the 6PI and 3500 rpm for the secondary injectors. See the 1987FSM, Fuel Section, non-turbo, page 4A-69 for the 3800rpm figure. The Turbo section of the 1987 manual does not mention this 3500rpm test for the secondary injectors.

I gauge it would take no more than ten minutes to check this out if the engine was hot when someone starts. That counts putting a small bolt in the vac hose....starting the engine...getting out and watching the actuators as you rev the engine above 3800rpm.

You can't do this with a cold engine. It needs to be warmed to operating temperature first.
Think about the great humanitarian service you'll do for non-turbo series five owners.

 

Hailers my good friend, why would you look in the 87 FSM for S5 info? You should know better. The Output Devices chart on page F1-77 of the 89 FSM says 3850rpm. For S4's the actual opening 6PI opening rpm will be far less precise due to all the variables affecting exhaust backpressure, particularly once the exhaust is modded. IIRC the 88 FSM doesn't actually mention a specific opening rpm.

As for the secondary injectors, according to my dash-mounted digital injector duty cycle meter (measuring the rear primary injector duty cycle in 1% increments) the secondaries come on at 3800+/-50rpm. Going up a steep hill in 4th gear at ~3/4 throttle allows plenty of time to watch the road and the tacho and the injector duty cycle meter to see when the changeover occurs.

 

My first twenty six words verify I know when the 6PI come on line. That's for a series five.

Out difference is in the secondary injectors rpm. The 3500rpm vs the 3800rpm. I suggest your tach is off quite a bit. Say three hundred rpm.

My RX-7 Bible, Series four 1987 FSM says 3500 rpm for the secondarys. Are you trying to make me lose faith????? Satan obviously lives in New Zealand.

Ohhhhhhh, I might just get the Fluke out and have a go at it. Up the hill watching meters instead of the road.

Sooooo....that means this post gets BUMPED to the top where it belongs til someone takes five minutes out of their life and does their good deed for the day.

EDIT: No, not up the hill watching meters. Just pulling the hose off the pressure sensor, plugging it and reving the engine in the driveway watching the meter.

 

Do the ports open up when the car is in neutral?

 

Got a point there. The series five says 3800rpm and under a load. The load would be the output of the pressrue sensor to the ECU.

See, on a series four non turbo, you can pull the vacuum hose off the pressure sensor and plug it. Then start the engine and rev it above 3800 rpm and the secondary injectors will start pulsing. You put a screwdriver handle to your ear and the other end to the base of the secondary fuel injectors and you can hear the clicking of the injector. The car does not have to be in gear to do that.

So we figure a person should be able to pull the vac hose on the pressrue sensor on a series FIVE and then start the engine. Reving the engine over 3800 should/might make the actuator rods of the 6PI move outwards. We'll never know until someone tries this. If it does not happen out of gear maybe try it in gear with the clutch pedal in.

So? Are you the guiena (can't spell) pig?

EDIT: GUINEA

 

I've heard of this, never tried it. I have a '91 NA. I'll have to find a friend to mash the gas pedal for me and I can find out. Do I just pop the hose off and put my finger on the end of it?

 

Yeah. Pull the hose off and plug the hole on the vac line. Use your finger if nobody else is around to help out. I use a small bolt to plug it. Then just start the engine and go to the engine bay and rev the engine using the throttle lever near the tps. Watch the 6PI actuators and see if they move outwards.

If that does not work, plug the line and have someone put the car in gear and rev the engine over 3800 rpm and watch the actuator. Thank you.

 

Yes.

Go do it!

 

I will do this if I get some free time (perhaps next friday). Can't do it until then because I am very busy with work and other things and probably won't even get in my car again until then.

 

OK. I went for a ride. Using the Fluke and the rpm reading on the SAFC I've come to the conclusion they come on at 3610-30 rpm and if you let off lightly they go off about 3510rpm. I did this in forth gear and later in second gear. I did it numerous times. Yes, the stock rpm gauge was reading higher than the Fluke 3610 rpm when the secondarys came on.

I also did it in the driveway. It was like fuel cut when they came on in the driveway. Sort of on/off. It helped to be actually driving rather than looking at the rpms in the driveway.

So my little red 1987FSM is wrong. I'm going to the used book store and buy a copy of MAO's little red book to replace it.

I surely wish someone would go out to their series five non turbo and cap off the hose to their pressure sensor and see if the 6PI work or do not work if you rev up in the upper range. Say 3850 plus. Thank you.

 

I would but ehhh I'm supercharged now, I don't have no stinking port actuators left!

 

so why are you even answering in this thread???

 

Hailers, give me twenty minutes and I will let you know the results. If it really requires a load on it , give me an hour. Ill take car over to Naval base and have kid step on in while I'm holding on and watching. Patience, Ill get back in a few minutes.

PEACE THE DOG

 

OK Hailers, here are the first results. 1990 FC3C, n/a, stock everything, all emissions garbage still intact and working. 3500-4500 rpms, in nuetral, pressure sensor attached, ports didn't open. Pressure sensor detached, 3500-4500 rpms, ports still not open.

In gear, clutch in, 3500-4500 rpms, pressure sensor attached, no change. And finally, in gear, 3500-4500 rpms, pressure sensor detached, no change. Gonna drive over to old Naval base and have son drive while I'm watching, and post what I find out.

Hope this has helped so far.

PEACE THE DOG

 

I have an S5 setup in my 1st gen. The 6pi system and VDI still work. I messed up one day and tried running the vacuum lines from the actuators straight to the intake manifold. That obviously didn't work. They won't open on their own with no vacuum lines hooked up to them either no matter what rpm or load you are at. I ran them to the exhaust for backpressure sensing. When the car is in neutral they will not open up regardless of rpm. When under load they will open up around the 4K mark or so. It varies with how hard you are really on it. If the engine is under a heavy load but at a lower rpm, it is possible to get them to open earlier than 3500 rpm. I just run them off the air pump now so they always open at the same rpm regardless of load.

 

Rotarygod, with that said, at what rpm do they actually open? You say around 4k rpm, how do you actually know this? I'm not being a smart ***, I'm just curious? Also, if you say they won't open without vacuum, the electronic aspect of this mechanism is really only for the ECU then? Correct?

From what I could tell doing my driving observation, it seemed that the actuators only opened with the vacuum hooked up to the pressure sensor. The reason I am questioning so intensely, is my actuators don't open until about 5500 to 5800 rpms, and not from visually observing, but actually driving, you really notice the difference. Should this be of concern for me, or what?

PEACE THE DOG

 

Yours may be stuck. At 5500-5800 you are feeling the VDI kicking in.

 

Sounds like the air pump is failing, or the actuators are in bad need of cleaning.

 

OK, just a few more questions if I might. I have recently read about testing with electricity, air, etc..... What is the best way of checking to see if they are opening or not? I can move the actuator rods by hand, but don't wont to tear down if possible. Any suggestions? And by the way, going 75 mph with the top down, stereo blasting, hood off, looking at the actuators was just like college days. And Hailers, I tried to answer your question, but unfortunately, if my 5th & 6th aren't working, no credible info here.

Thanks Guys,

PEACE THE DOG

 

yes you should be able to move them by hand, and very easily on a S5 (the S5 ones need only half the pressure, that the S4 ones need).

 

Yes Ice, they do move freely by hand, but my concern now is how can I actually tell if they are working internally, I guess that is how to explain it? Put it to the air an electricity solenoid test? It just doesn't explain exactly how to know if they are working internally.

From what I have researched, just because your actuators are functional, it doesn't mean that the ports are functionally properly. Correct?

Sorry again Hailers, not trying to take away from your original question, just don't want to post information to you that may be incorrect.

PEACE THE DOG

 

HAILERS, i can back up mombodogs findings. i did this sometime in the summer to test if the solenoid would open that way. it doesn't. there is some other factor the ECU needs or rather just revving it with the sensor unplugged is not meeting the proper activation criteria. this is what the FSM says about it:

INPUT/OUTPUT relationship chart, solenoid valve (6 port injection):
- airflow meter (afm)
- water thermosensor
- crank angle sensor (g+,g-)
- neutral switch (m/t)
- clutch switch (m/t)

OUTPUT devices chart:
- OFF - cranking (when engine is cold), idle (during warm up), medium load COLD, deceleration (throttle valve fully closed), idle (when engine is warm), ignition: on (not engine run)
- ON (above 3850 rpm) - medium load WARM, acceleration, heavy load


so, MY deduction on this gives the following ON conditions:
- afm open ABOVE a certain level
- water thermosensor ABOVE a certain temperature
- crank angle sensor reading...acceptable (whatever that is?)
- car is NOT in neutral
- clutch is ENGAGED
- ABOVE 3850 rpm

i believe the pressure sensor has NOTHING to do with the opening of the 6pi system on the S5. my theory was load was determined by TPS, medium load being ABOVE 50% of calibrated value...but the I/O chart says otherwise, so really it does not say at all how it determines load for this.

 

Good info coldfire, but I'm not only trying to help Hailers get a definitive answer to his original post, but I am also wanting the answer to how to know if they are actually functioning. I don't have a dyno handy, otherwise I would put in on the dyno and watch as
the rpms and speed increased. Otherwise, I go with the caveman method I tried earlier.

It would be nice to actually know the answer. All the testing is great, if you have something concrete to back up the testing.

PEACE THE DOG