Stock 74 350 (J Code) need part identification
Thread Starter
Heel & Toe
Joined: Jan 2010
Posts: 19
Likes: 0
Stock 74 350 (J Code) need part identification
I have a strictly stock 1974 350 J code engine with no power steering, power brakes or air conditioning. The car does have all the original emissions control, AIR pipes, smog pump, you name it.
My problem is that on the right side of the intake manifold there is a small "canister" that has both electrical and vacuum functions that is rusted and I believe needs to be replaced. There is a two prong electrical connection and a single straight Metal vacuum connection on the base while the top or opposite end has a single plastic "T" for two vacuum hoses. Given the length of the electric wire, it appears that the integral bracket is designed to be attached beneath one of the intake manifold bolts. I have not found any part number on the canister or the bracket.
A) What is the part called?
B) What is it's function?
C) What are the three vacuum lines supposed to be attached to?
Any and all answers will be greatly appreciated.
My problem is that on the right side of the intake manifold there is a small "canister" that has both electrical and vacuum functions that is rusted and I believe needs to be replaced. There is a two prong electrical connection and a single straight Metal vacuum connection on the base while the top or opposite end has a single plastic "T" for two vacuum hoses. Given the length of the electric wire, it appears that the integral bracket is designed to be attached beneath one of the intake manifold bolts. I have not found any part number on the canister or the bracket.
A) What is the part called?
B) What is it's function?
C) What are the three vacuum lines supposed to be attached to?
Any and all answers will be greatly appreciated.
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
I have a strictly stock 1974 350 J code engine with no power steering, power brakes or air conditioning. The car does have all the original emissions control, AIR pipes, smog pump, you name it.
My problem is that on the right side of the intake manifold there is a small "canister" that has both electrical and vacuum functions that is rusted and I believe needs to be replaced. There is a two prong electrical connection and a single straight Metal vacuum connection on the base while the top or opposite end has a single plastic "T" for two vacuum hoses. Given the length of the electric wire, it appears that the integral bracket is designed to be attached beneath one of the intake manifold bolts. I have not found any part number on the canister or the bracket.
A) What is the part called?
B) What is it's function?
C) What are the three vacuum lines supposed to be attached to?
Any and all answers will be greatly appreciated.
My problem is that on the right side of the intake manifold there is a small "canister" that has both electrical and vacuum functions that is rusted and I believe needs to be replaced. There is a two prong electrical connection and a single straight Metal vacuum connection on the base while the top or opposite end has a single plastic "T" for two vacuum hoses. Given the length of the electric wire, it appears that the integral bracket is designed to be attached beneath one of the intake manifold bolts. I have not found any part number on the canister or the bracket.
A) What is the part called?
B) What is it's function?
C) What are the three vacuum lines supposed to be attached to?
Any and all answers will be greatly appreciated.
Thread Starter
Heel & Toe
Joined: Jan 2010
Posts: 19
Likes: 0
Yes, the car is a four speed. If this is the Vacuum Advance Solenoid and I am correct, one hose goes to the distributer, and a second goes to the carburetor - what connects to the third outlet? Is it by any chance the air pump diverter valve?
Thanks again,
Thanks again,
Last edited by Paul ADK; Mar 2, 2010 at 09:24 AM.
Melting Slicks
Joined: Oct 2005
Posts: 2,056
Likes: 8
From: Redruth Cornwall
Ebay, NOS,
http://cgi.ebay.com/ebaymotors/73-4-...Q5fAccessories
priced at $69.99 + $5.00 shipping! eek..is that a god/bad price???
http://cgi.ebay.com/ebaymotors/73-74...Q5fAccessories
$59.95 + $8.00 shipping.
http://cgi.ebay.com/ebaymotors/73-4-...Q5fAccessories
priced at $69.99 + $5.00 shipping! eek..is that a god/bad price???
http://cgi.ebay.com/ebaymotors/73-74...Q5fAccessories
$59.95 + $8.00 shipping.
Last edited by jotto; Mar 2, 2010 at 11:01 AM.
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
The four-speed and Th400 solenoids are different. My car is an automatic. The units referenced above seem to be for a four-speed.
As I understand (not well) with the TH400 one hose goes to the vacuum advance, one goes to manifold vacuum, and the third to ported vacuum. The electrical connection is to the thermal switch in the passenger side head between cylinders # 6 and 8. How this all comes together is a mystery to me. So I just gave up and removed it.
Much the same with the seat belt interlock system. Just gave up and it is gone.
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
The solenoid inhibits the intake vacuum signal from getting to the advance unit on the distributor except for select circumstances. I think the transmission must be in 3rd or 4th gear, and the motor full warmed up.
I don't remember there being three ports on the solenoid, only two.
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
The solenoid inhibits the intake vacuum signal from getting to the advance unit on the distributor except for select circumstances. I think the transmission must be in 3rd or 4th gear, and the motor full warmed up.
I don't remember there being three ports on the solenoid, only two.
I don't remember there being three ports on the solenoid, only two.
I have been poking about on this one during the day. The GM numbers for this (1973-74, 350cid) are 1997410 for the four-speed and 1997425 for the TH400. The former has two spouts and the latter three as per my pic and for the routes I have noted.
So the first EBay post above is correct for the manual transmission (and stated as such) and the second mis-labelled: it for an automatic. Note the three spouts.
This diagram shows the three ports. The TCS system is operating on both manifold and ported vacuum. That is where I became confused and just gave up.
Last edited by Paul L; Mar 2, 2010 at 05:23 PM.
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Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
Here's a diagram from Doc Rebuild that confirms the three hoses but is not clear as to where they each go
http://www.docrebuild.com/dr-r-web/3750355.HTML
http://www.docrebuild.com/dr-r-web/3750355.HTML
Team Owner
Joined: Aug 1999
Posts: 30,995
Likes: 99
From: Ontario
Here's a diagram from Doc Rebuild that confirms the three hoses but is not clear as to where they each go
http://www.docrebuild.com/dr-r-web/3750355.HTML
http://www.docrebuild.com/dr-r-web/3750355.HTML
