today while the car was sitting in nuetral i had someone give it gas while i watched the aux port actuators. they revved it to 5k and i saw the actuator jiggle a bit but it never opened the port. I'm wondering if maybe the car has to be under load for them to open, like on a dyno or driving down the street? or is it time to do the airpump trick? maybe they're just stuck? i replaced the larger cat with a highflow and put racing beat mufflers on the car, i would assume i still have enough back pressure.

 

S4 stock cars have to be under load, yes...

 

ah ha, thanks.

 

Series 4 or Series 5?

The S5 cars (89-91) do open only under load, and are powered by the airpump. The ECU switches the 6ports via a solenoid only under load.

S4 cars work off pressure in the exaust. Technically they would only open under load... as revving doesnt really create alot of exaust gases (same principle of revving a turbo, and not seeing full boost)

You can test to see if they're stuck... just actuate them manually.... If they move, then you don't have to bust your intake manifolds off

You can also test by placing some grease all on the shaft of the actuator... and "sculpt" the grease smooth (hard to explain) just so you can tell if the grease has been moved/smudged (the actuators working).

 

good idea with the grease, thanks!

 

I can't believe this topic is being discussed today. Perfect timing. I just happened to apply some grease to test my 5&6. My question is how much are they expected to move?? Mine did move, but only about .5cm or around 1/4 inch.

 

S4's should move damn near all the way down...If yours moved only 1/4", you've got pressure-just not quite enough...

 

hmm....any suggestions on what to look at next?

 

Well, what do you have? Stock exhaust, with 16 year-old cats? Or something else?

 

'87 GX
Stock everything (Dual exhaust)
Just replaced old air filter
Motor was just rebuilt by Mazda about 1200 miles ago.
S4 edition

 

I guess first thing I should probably do is make sure the actuators are cleaned up a bit.....just in case they're sticking.

 

They can stick every now & then, the more excuse to kick her in at least every day or two to keep everything nice & "limber"...You should be able to push them down by hand. I've used very light low-temp grease (Dow Corning DC-33) on the shafts before to keep 'em lubed, it seems to work. Don't put big chunks of heavy grease on 'em, or it will tend to attract grit, which may jam the rods at some point...If you have a source of compressed air, you can pull the hose of of the split-air pipe nipple, and shove some pressurized air in there to see what they're doing (be careful so you don't blow the diaphragms, if there are any in there)...You should feel them kick in along with your secondary injectors at about 3800 rpms under load, if everything's working right...

 

Thanks for the hints.
I appreciate it.

 

Just buy a two foot long piece of vacuum hose and attach it to the feed pipe at the actuators. Blow hard into the line. The actuators should retract. Or do the same but use low pressure air from your air compressor. Talking series four.

 

I found them fairly stiff when I moved them with just my hand. I doubt I could blow hard enough to get the actuators to move on their own.
As noted earlier, the mazda dealership just rebuilt the motor a short time ago. I'll probably give them a hollar to take a look at them if the situation doesn't improve with some cleaning and manual "actuating".

 

I wonder if the port sleeves are carboned/gummed up. It just sucks that you have to take the LIM off.

 

If you've been running with the OMP all this time, they will tend to get gummed up in the port passage. Yet another reason to go premix

 

Dude... don't take it to the dealer.

Learn to work on your car. You won't regret it.

Taking off the intake manifolds to get to the ports is not that hard, just be sure to label all your vac hoses, and sensor plugs JUST IN CASE you don't remember where everything goes. Download the FSM (section 4A... fuel and emissions) and just study that ****... helps alot.

I'd say it takes 2... 3 hours tops if its your first time doing anything with your car to take off all the manifolds.

 

Just be careful if you decide to go for it yourself- some of them can get stuck in there pretty good, and you will tear them up trying to get them out. If you run into this, try injecting some form of penetrant oil and working the port cylinder in & out until she finally lets loose. They usually hang up after you've pulled it about 1/3 the way out already. Just be patient...

 

maybe it's just me but i can tell my ports are working just by listening carefully for them. it's like a whooshing sound right at 3800-4000 rpms, then the car proceeds to haul alot of ball!!!!!!!!

 

All of this is wise advice. I have to take her out of town this weekend, and by the sounds of it, this is probably a weekend project. I'm not sure if I'm going to tackle it or not. I think I can handle it, but I don't have much for tools and chemicals, (Money is a little tight right now too.) but we'll see. The more I read over your posts, the more I'm figuring I can give it a shot. I would LOVE to have these two ports going.

 

Firstly... Get a mighty-vac and a cheap vacuum/pressure gauge and a "t" fitting.. use the T in a hose from the mighty-vac pressure side the connection on the lower intake manifold. Put the pressure gauge off the "t". So you can see how much pressure you are supplying to the actuators. 2-4 PSI will open them completely if they are operating correctly. If that works... Put the "t" in the line between the split air pipe and the connection on the LIM. Run a long hose into the car with the pressure gauge on the end of it. Step on the gas and see when 2-4 PSI is developed. I should develop @ about 3700 RPM or so. This is the best way to diagnose your car.