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engine:vacuumrouting [2025/05/09 05:41]
47.238.13.14 old revision restored (2025/04/17 09:25)
engine:vacuumrouting [2025/05/09 15:57] (current)
114.119.138.214 old revision restored (2025/01/24 07:08)
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 ====== Vacuum Routing ====== ====== Vacuum Routing ======
  
-Vacuum routing is slightly different between certain model years (and US/UK models).  +Vacuum routing is slightly different between certain model years (and US/UK models). Most of this is US-centric information.
-Most of this is US-centric information. This page attempts to disentangle all the vacuum lines in the engine compartment. +
- +
-The US cars had air pumps equipped for emissions compliance.  +
-Most owners removed this system due to the fact that it would frequently break.  +
-The diverter valve and the associated plumbing is usually removed. My car kept the diverter valve to make use of the vacuum connecter on the top.  +
- +
-{{:engine:screen_shot_2021-12-22_at_8.49.00_pm.png?600|}} +
- +
-As explained below, the two red boxes are the vacuum solenoids for fuel pressure and ignition.  +
-When the solenoids are not energized: +
-  * Purple and Magenta lines are connected (ignition) +
-  * Blue and Cyan lines are connected (fuel pressure) +
- +
-When the solenoids are energized: +
-  * Purple and Yellow lines are connected (ignition) +
-  * Cyan and Green lines are connected (fuel pressure)+
  
 +The US cars had air pumps equipped for emissions compliance. Most owners removed this system due to the fact that it would frequently break. The diverter valve and the associated plumbing is usually removed. Additionally, although the vacuum diagram seems to indicate that there is a line coming off the vacuum pump, this doesn't appear to be the case for many cars.
  
 +{{:engine:screen_shot_2021-12-21_at_9.38.54_pm.png?600|}}
  
 +As explained below, the two purple boxes are the vacuum solenoids for fuel pressure and ignition. When the solenoids are not energized, the yellow and green lines are connected (ignition), and the yellow and orange lines are connected (fuel). When the solenoids are energized the blue and green lines are connected (ignition) and the red and orange lines are connected (fuel).
 ==== Vacuum Solenoids ==== ==== Vacuum Solenoids ====
  
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 == Fuel Pressure == == Fuel Pressure ==
  
-Located beneath rear of plenum chamber. Function is to reduce fuel pressure on 'overun' and idle. A micro-switch, mounted on the front of the front carburettor, and operated by the throttle lever in its fully closed position, energises the fuel pressure solenoid. The signal to the fuel pressure regulator (normally connected to boost pressure in the plenum chamber) is then switched to No.1 cylinder inlet manifold depression, thus reducing 
-fuel pressure to the carburettors and mixture strength under closed throttle 'overun' conditions. 
  
 == Replacement == == Replacement ==
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 {{:engine:solenoid-diagram.jpeg?400|}} {{:engine:solenoid-diagram.jpeg?400|}}
  
-The least expensive replacement unit is an A/C Solenoid Valve part 1470004 or SW9000.  +The least expensive replacement unit is an A/C Solenoid Valve part 1470004 or SW9000. This operates in a similar fashion to the stock unit as long as you set up the vacuum lines properly. These can be purchased for about 1/2 the cost of the Pierburg unit.
-This operates in a similar fashion to the stock unit as long as you set up the vacuum lines properly.  +
-These can be purchased for about 1/2 the cost of the Pierburg unit, however, note that the connections are 5mm which are bigger than the stock vacuum lines.+
  
 {{:engine:12-2114cad.jpg?400|}} {{:engine:12-2114cad.jpg?400|}}
  
 {{:engine:719zinu_ndl._ac_sl1500_.jpg?400|}} {{:engine:719zinu_ndl._ac_sl1500_.jpg?400|}}
engine/vacuumrouting.1746769279.txt.gz · Last modified: 2025/05/09 05:41 by 47.238.13.14 · Currently locked by: 114.119.147.32,10.179.80.163