6-ports not working - not typical failure -
 

I have the usual non-working 6 ports on a 91. They are not mechanically stuck though, well they were. I just took apart the intake and cleaned them up because they were seized solid. One shaft was so stuck we had to beat it out if the manifold with a drift punch.

Everything operates silky smooth now but the computer is not turning on the solenoid to operate them. I have checked the solenoid and it works fine. I blow into the line that goes to the actuators and they open. I switched the VDI valve solenoid wires onto the 6 port solenoid and then the 6 ports work. I put a multimeter on the connector and I'm getting no voltage to the solenoid. So it is for sure the ECU not turning them on. All this checking was done revving the car in neutral BTW.

Any ideas on why the ecu isn't doing its job?? Is there some sensor input to the ecu that might be bad? Is the 6 port actuation purely RPM based? Does it not open them in neutral??

I don't have a wiring harness to see if there is anything else in line that switches that solenoid. I searched all over the place but can't find any ECU wiring diagram for ths car online. I found one for the body and one for the engine electrical pieces but not the ECU and various solenoids etc..


Thanks very much for any help!!

The 89 manual says on page FI-81.....The aux actuator work only over 3800 rpm and under load only. I never set eyes on a 89 and above model, but, I find it strange that you find no 12v at the solenoid. On most of the solenoids, you find 12v constantly on one wire, usually a black/white wire. The other wire will have a ground put on it by the ECU to activate the solenoid.

Then again I look at the manual online, and its says the VDI only works above 5200rpm while driving. So why does yours work in the driveway on the aux actuator solenoid???With the plugs swapped? Possibly because these cars have two types of solenoids. Some pass air when not energized, and the others only when energized. I suspect these are two different solenoids.

So I'd try to find out why one of the two wires does not have 12v on it constantly, and if the other wire is getting a ground put on it when under load above 3800 rpm.

By the way, if you do find 12v on one of the wires, try this......Pull the vac hose off your pressure sensor, plug it with a small screw(the hose, not the sensor). Now rev the car and see what happens. Pulling the hose off the sensor just might fool the pressure sensor into thinking the car is under load.

Really shoulda had 12v at the solenoid on one wire.......

I was just checking voltage across the two wires. I didn't think to check if one was getting power or not.

thanks for the page reference in the manual. I did notice that it says "cannot check" engine must be under load. where as for the vdi valve it doesnt say that. so maybe it is working just fine and they dont kick in while revving in neutral.

So at least I have some things to check out