Hey guys,

I have a 1990 NA and I recently cleaned my 5th and 6th ports ( removed the manifold and physically removed and cleaned them). They open with about 2lbs of pressure with a vac/pressure tool , but I cannot get them to open at all while driving. I am pretty sure I have all of my vacuum lines correct. Can anyone help me on a troubleshooting procedure reguarding the soleniods or the vacuum lines and which ones.

I have a bones presilencer race pipe... no cats and the splitair pipe opening on the back of the manifold is just left open. I have not removed the acv or air pump.

This is killing me .. I went to all the trouble the tear down the thing to get the ports loose and working and now they aren't operating after all that effort. I hate to waste time on anything.

 

i have a question about my 6th ports too. on my 88 is it true that my air tube to the last cat is what makes them open because mine is unhooked and i don't feel much of a difference when i go past 3800 rpm.

 

On a series 5 car, (89-91) the ports are opened by the air pump.

On a series 4 car, (86-88) the ports are opened by exhaust backpressure.

Series 5 cars can leave the air tube open in the back and no ill effects as far as I know.

Series4 cars need that pressure to push open the ports.
You should therefore use a hack of some sort from the air pump to open them.
use a RPM activated vaccum solenoid to allow pump air to push the ports open or somthing.

The S5 factory service manual (FSM) gives series 5 owners the ability to debug the ports via checking the engine codes from the ECU and then also by giving step by tesp procedures to test the individual compnents of the system.

the S4 FSM only shows how to pull codes from the currently running engine sice codes are lost each time you shut off the engine.
But it also shows how to diagnose the system step by step.


Solenoid Valve test Steps:


Series 4 cars test method is a bit more complex but similar to series 5.

Go to WWW.FC3S.ORG and download the '88 factory service manual from there and see the N/A fuel and emission section, just like on the series 5 manual.

However you need to start reading on page 4A-40 and go from there.

you could/should also pull codes using the method described, however you will need to identify which wire pulses out the signal for the checker to count the pulses and tell you the engine codes.

Series 5 owners have the luxury of having a check engine light flash out the code for them.

You can use a needle type volt meter ow low current 12V bulb to do the same thing from the harness.

 

MRHICKS........Why not go to the brown 6pi solenoid, take both hose off, connect them together with a thrity cent plastic union available at PEPBOYS, start the engine and see if the actuators actuated. At least that would show that there is nothing physicaly wrong with the connection b/t the actuators and the solenoid. Then you can concentrate on finding out why the ECU isn't sending a signal for the 6pi brown solenoid to open?????? And how do you KNOW that they are not opening????????????????????????????????????????

 

Thanks for the input you guys. I will do exactly what was recommended and get back to you tomorrow.

oh yeah, I know the 6-ports were not opening because I did the dab of grease test very carefully.

 

do not oil your sleeves with anything more than WD-40.

otherwise they will gum up again...fast.