secondaries not opening. I think?

[shorook90]

well, I had a vacuum line disconnected from the back of my intake manifold and recently got it fixed. 1,000-3,900 has a big improvement of power now but I still do not visually see the secondaries shut at start up. Do you guys know where the moving part is on the manifold? I really dont know where to look on start up to see if the secondaries are closing or not. If not are then what do you think could be the problem? another vacuum line or a sensor of some kind? any information will help. thanks again guys. thumbs_u

 

[BlackOnBlackATX]

um, i dont think you can actually see it since the butterflies are in the runners, i could be wrong on this but im pretty sure about that. if theyre not opening youll know it when you hit 4 grand. if you cant hear em, they aint there. but check your connections on the manifold and listen for some vaccum leaks. i think thats your best bet if you really dont think theyre opening. now if you dont think theyre *closing* on startup as you said you will feel the power loss, which you said you dont, so thats prob not your problem. besides, they should already be shut on startup since they only activate at 4k rpms. someone stop me if im wrong....

 

[BeatDaSHO]

yo man. yes u can see where the secondaries are functioning. look at the picture of the SHO engine at the top of the page......if you look at the top of the engine between the first and the second runners at the top, you will see the actuator which opens and closes. blip the throttle while looking at the engine, get the rpms over 4000 and you will see if the actuator moves or not.

Greg

 

[BlackOnBlackATX]

ok, i see the actuator in the picture. my bad, but i thought you couldnt run the engine up to 4k in park or neutral? isnt that part of the safety program? im 99% sure on that since its to save the torque converter from overheating.

<small>[ February 18, 2003, 10:27 PM: Message edited by: BlackOnBlackATX ]</small>

 

[AutoSHO]

BlackOnBlackATX:
ok, i see the actuator in the picture. my bad, but i thought you couldnt run the engine up to 4k in park or neutral? isnt that part of the safety program? im 99% sure on that since its to save the torque converter from overheating.

Only you poor people with ATX's suffer that malady

Also, I wanted to point out one bit of mis-information you had: Engine Vacuum closes the secondaries, so when the car is off, they are open. When you start it they close, and then open again at 3,950 rpms.

 

[NotSoSlowSHO]

little late in the thread... but this may help for others...

 

[c_olcott]

heh heh, I obviously did not start this thread but I do have the same problem! Nothing moves when I start the engine or when when RPM's go over 4k. I dynoed at 180hp/180tq while stock. I would assume that they are stuck open because of the power numbers being about normal, also from reading, I do not hear any "vaccuum" leaks or anything odd. Does anybody have any other ideas?

 

[projectSHO89]

C_olcott,

Inspect the hose routing using my post from a couple of days ago at http://www.shoforum.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=17;t=005579#000007

Inspect that and see what turns up.

Steve

 

[BlackOnBlackATX]

quote:
--------------------------------------------------------------------------------
Originally posted by BlackOnBlackATX:
ok, i see the actuator in the picture. my bad, but i thought you couldnt run the engine up to 4k in park or neutral? isnt that part of the safety program? im 99% sure on that since its to save the torque converter from overheating.
--------------------------------------------------------------------------------

Only you poor people with ATX's suffer that malady

Also, I wanted to point out one bit of mis-information you had: Engine Vacuum closes the secondaries, so when the car is off, they are open. When you start it they close, and then open again at 3,950 rpms.

DAMN MY ATX TO ****!!! thanks for the info, just got in so i read everything from last night. i dont recall seeing that area that was in the pic a few replies back. in the daylight tommorow ill have to take a peek.

 

[c_olcott]

Ok I followed the hoses from the "cylinders" to the T connector and then to the small black "cylinder" in the back of the engine and then back into the intake (I'm not entirely sure of the terms for these things). There were no cracks and also no tubes unconnected. I am able to push onto the small "******" on the butterfly and that pushes a small rod into the "cylinder". Not sure which way is open or closed. Would it be a good idea to pull on of the tunes off and see if air is flowing through the tubes? let me know thumbs_u

<small>[ February 20, 2003, 11:59 AM: Message edited by: c_olcott ]</small>

 

[projectSHO89]

No, don't take it apart.

I'll post pics shortly that will give you what to look for.

This first photo is of the rear bank Intake Air Control motor with the engine OFF. The secondary is ope. I highlighted the tab with some white-out to help identify the position of the lever.

The second photo is after starting the engine. Note the now vertical position of the marked tab.

Steve

<small>[ February 20, 2003, 12:45 PM: Message edited by: projectSHO89 ]</small>

 

[c_olcott]

I am photo one at all time !

 

[projectSHO89]

Then you are "broken".

Only thing in the circuit is the IAC solenoid (check the electrical connector) and the vacuum connection that goes from the manifold to the small black reservoir to the solenoid.

If there is nothing visibly wrong, locate the hose from the T to the solenoid, disconnect it from the solenoid, and connect it to the ****** on the intake manifold (if it reaches). Start the engine and see if the butterflies now close.

If so, you have one of the following: open vacuum line for the small reservoir (somewhere between the intake manifold ****** and the solenoid connection, defective control signal from the PCM, or a defective solenoid.

To perform the electrical checks, you will need a voltmeter. An inexpensive and perfectly adequate digital meter can be purchased at Sears or Radio Shack for $20.

Disconnect the connector to the IAC solenoid. Start engine. Measure at the RED wire to the connector. If you read battery voltage (Vbatt), proceed to the next step, otherwise troubleshoot the EEC PWR circuit from the IRCM. Different subject, will be covered if needed.

Leave engine on and e-plug the connector back into the IAC solenoid. Backprobe the connector's RED wire to verify that Vbatt is still present. If so, go to the next step. If not, possible bad connector or an internal IAC solenoid short.

Backprobe the other wire for the IAC solenoid. My 89 EVTM says the wire is Pink/Yellow, yours may vary by year.

If the voltage reading is near 0 volts but the solenoid did not switch the vacuum, replace the solenoid.

If the voltage reading is near Vbatt, momentarily short that line to chassis ground and watch the butterflies. If they switch when the line is grounded, then either there is an open circuit between the IAC solenoid connector and PCM pin 32 or the output driver in the PCM is defective.

There ya go, a relatively complete troubleshooting procedure for the secondaries.

Steve

 

[shorook90]

I have now inspected every vaccum hose that is connect to the manifold and there is no more leaks. So it is either a faulty signal from eec-4 or a bad IAC right? Would replacing the IAC correct the problem? Does the solenoid come with the IAC? Would the check engine light come on if it was a faulty IAC? If it is a faulty signal from the EEC-4 then what needs to be replaced? Sorry for so many questions guys but my dad put it in my hands to find out what is wrong. thanks for all your guys help!

 

[projectSHO89]

Did you perform the diagnostic steps I posted?

If not, do so. Otherwise, you're just spinning your wheels and/or guessing.

Those steps were written with the intent that the steps would be followed, not ignored.

If you don't feel up to performing them yourself, take it to a shop or just continue to guess.