more problems!!!

[coldsho]

got the intake back on but now
the rear secondaries open up
even with the throttle and not at the proper time
(i think didnt get that far i blew a coolant
line and had to turn around before i found out
how it works) anyone had this problem before?
pinched line or something?

 

[Mike Kopstain]

I have absolutely no idea what you said... can you phrase this in comlete sentences?

 

[coldsho]

i got my intake put back on.. now the rear secondaries move in conjunction with the throttle. is it possible that i pinched something when i was putting the intake back on, i cant tell if the secondaries work properly cause i blew a collant line before i could do a proper test.

 

[Mike Kopstain]

well if the secondaries are moving in conjunction with the throttle, you may have somehow attached the secondaries straight up to engine vacuum. Don't know if or how you pulled that one off.

How is the front row?

 

[projectSHO89]

Reconnect the electrical plug for the Idle Air Control valve. That is the valve on the back (firewall ) side of the intake that controls the opening of the secondaries. Verify you hooked up the vacuum lines to the secondary accumulator (that's the the small black cylinder next to the IAC valve.

Inspect the vacuum line that goes from the IAC valve, to a T fitting, and to each of the the IAC motors (secondary butterfly valves). You may have pinched it.

Steve
89

 

[luigisho]

I pinched the vacuum line to the secondaries when I put the intake back on once. In fact I mashed it totally because I torqued the intake down on it really tight.

 

[sdpatt]

projectSHO89:
Reconnect the electrical plug for the Idle Air Control valve. That is the valve on the back (firewall ) side of the intake that controls the opening of the secondaries.

No. The idle air control (IAC) valve is located on the inside, right of the intake when viewed from the front of the car. The IAC valve allows the EEC to control the amount of intake air bypassing the closed throttle plate at idle.

The vacuum accumulator (storage tank) is the black, plastic, film canister sized part on the center of the rear intake plenum. There should be an electrical connection to a solenoid valve on the driver side of the solenoid.

The secondary butterflies are closed by vacuum and opened when the solenoid vents the vacuum to atmosphere. The valves are open when there is no vacuum supply (engine stoped for a long time) and can be closed only when the vacuum is applied (when the engine starts).

Here is the correct routing for the secondary butterfly vacuum lines. Please try the search. It can save you from having to type a lot of questions.

 

[projectSHO89]

No. The idle air control (IAC) valve is located on the inside, right of the intake when viewed from the front of the car. The IAC valve allows the EEC to control the amount of intake air bypassing the closed throttle plate at idle.

Actually, that is the ISC (Idle Speed Control) also called the Air Bypass Valve in the Helms.

The IAC valve is the valve on the rear of the intake that controls the the RH and LH IAC motors (butterflies).

Re: 89 EVTM, 89 SHO Helms, and underhood vacuum diagrams.

Personally, I had never before noticed the correct IAC terminology until I dug into the manuals today, except for your post here: http://www.shoforum.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=17;t=001914#000002 . Hadn't seen them called by that name in the last year either here or on the mailing list, either.

Steve
89

<small>[ September 20, 2002, 08:50 PM: Message edited by: projectSHO89 ]</small>

 

[coldsho]

the fronts now doin the same thing with the throttle but i cant seem to see where its hooked up wrong. is it bad to run without sceondaries?

 

[Chrisssssssss]

I don't think thatit would damage anyting to run without the secondaries (but I could be wrong) but the car would not be performing well. Heck, you could even say that the secondaries put the "S" in SHO. Without the "S" you have a Pontiac Grand Am. (Sorry, not a flame ...Joke here )

 

[coldsho]

now both are now working with the throttle, is that normal, they didnt do that before

 

[sdpatt]

The secondary butterflies are controlled by the electronic engine control (EEC) to open at 3,950 rpm. They are not throttle dependent. That indicates that the electrical solenoid on the secondary control circuit is not in the vacuum path to the actuators.

And once again, since mauals can be published with errors, the idle air control (IAC), idle speed control (ISC) or idle air bypass (IAB) valve is the electrical servo operated device located just to the passneger side of the split in the intake manifold at the throttle body. The black, plastic vacuum accumulator and vacuum solenoid valve that control the secondary runner butterflies are mounted to the bracket attached to the center of the rear intake plenum by the 12mm bolt.

The secondary butterflies are closed at speeds below 3,950 rpm (or slightly less with an add-on LPM) to enhance low rpm torque output and opened above this speed to increase the high rpm power output. The secondary butterflies have no bearing on the control of the idle speed. They are strictly either open or closed and have no throttling capability. The electrical servo on the idle air control (or IAB or ISC) valve, however, is designed to throttle varying amounts of air past the closed throttle plate at idle. Hence the name, idle air control (or idle speed control or idle air bypass, depending on what reference you are looking at) valve.