Unfortunately, I don't have a picture nor have I really gotten under the car to find out exactly where the hose leads to...

Basically, it plugs into the full-time vacuum in the back of my q-jet. I had the 700R4 replaced a few years ago with a re-built 89-90 version, so I don't know for sure if it was added then or not.

My reason for asking is that I am ditching the computer controlled q-jet and therefore the torque converter lockup will be disconnected too. I was also told that there is a vacuum switch that can be installed to fix this... maybe I all ready have one? How can I find out before I go and spend $50 on one?

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1984 z28 w/ a 357 cu in. monster engine which is looking like the posterchild for Edelbrock... all the suspension stuff... 9-bolt posi disk is in... K&N filter... 93 octane...

-=ICON Motorsports=-

 

There's no vaccuum hose that ever goes/went to a 700r4.

Any vacuum switch (previously added, or one you add) would be external to the trans.


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-Tom P (Hot rodded 1986 Firebird 2.8l) from http://www.f-body.net/mailbag/3rd/3rd_mailbag.html message boards
---Think your car could be pic of the week? Visit http://www.f-body.net for details!

 

I'm not sure that one wasn't added when they installed the 700R4 when the shop rebuilt it. It was about 3 yrs ago and I since I didn't know much about trannys (which was exactly why I had someone else do it), I didn't pay too much attention.

It is a hard plastic line that was plugged into the rear of the q-jet right next to where the brake booster hose goes in. I cannot tell if it was there stock or not. I cannot think of anything else that it would go to other then the tranny, but it kind of goes behind the motor so I cannot really tell. I would have looked when I had the motor out last year if I had known to look, but hindsight is 20/20...

 

It does not go to the tranny. It sounds like what may go to the HVAC under the dash, or to the vacuum reserve/cruise control.

------------------
If you live in Southeastern US, check us out!
South East Thirdgen


ASE Master Tech + L1
Savannah, GA

'87 Trans Am
S/D TPI retrofit including functional PassKey,
22# injectors,
JET AFPR,
Ported Plenum,
TB Coolant Bypass,
SSM SFC,
Boxed LCAs,
8mm Accel wires,
Flowmaster Exhaust,
16" GTA rims,
Corvette Servo,
KYB Shocks
-->14.97 @ 94.9 MPH<--

'97 Bonneville SSE

 

A guy on the carb board says it goes to some sensor that compairs the intake vacuum to the apmosphere pressure and tells the ECU to retard the timing...

Thanks

 

He is talking about the MAP sensor, which is a possibility that I forgot about.

------------------
If you live in Southeastern US, check us out!
South East Thirdgen


ASE Master Tech + L1
Savannah, GA

'87 Trans Am
S/D TPI retrofit including functional PassKey,
22# injectors,
JET AFPR,
Ported Plenum,
TB Coolant Bypass,
SSM SFC,
Boxed LCAs,
8mm Accel wires,
Flowmaster Exhaust,
16" GTA rims,
Corvette Servo,
KYB Shocks
-->14.97 @ 94.9 MPH<--

'97 Bonneville SSE

 

If a 1984 z28 came with a MAP sensor... I guess it did. It is nice to know I can disconnect it or whatever and not face too many problems now that I am by-passing the ECU. I guess I will have to install a vacuum switch to lockup the converter now...

 

You don't need a vacuum switch, just a manual switch.

------------------
If you live in Southeastern US, check us out!
South East Thirdgen


ASE Master Tech + L1
Savannah, GA

'87 Trans Am
S/D TPI retrofit including functional PassKey,
22# injectors,
JET AFPR,
Ported Plenum,
TB Coolant Bypass,
SSM SFC,
Boxed LCAs,
8mm Accel wires,
Flowmaster Exhaust,
16" GTA rims,
Corvette Servo,
KYB Shocks
-->14.97 @ 94.9 MPH<--

'97 Bonneville SSE