There is hardly any info on the TB42e - especially the fuel/inlet system. Thought I'd share what took a long time to find out.
Had to repair a water leak at the back of the block (heater hose outlet) which was almost impossible to get to due to the inlet manifold and all the junk attached to it.
Figured the best way was to remove the inlet manifold to get to the heater hose - what a stupid "Mitsubishi" design (thought I'd sold my Delica ? )
Anyway the vacuum hoses, water hoses and control valves can be greatly simplified - allowing easier future access and a less junk crammed engine bay.
Sorry there are no pictures of "before", but if you want "before", open your bonnet/hood.
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This is your fuel pressure regulator - it senses manifold vacuum and regulates the fuel injector rail pressure to be a set amount above the manifold vacuum/pressure - to provide a fixed amount of difference between fuel pressure and manifold vacuum .
Necessary for proper control of the fuel injection system.
No matter how big a "racing fuel pump" you fit, this valve just bypasses the extra fuel supplied to return to the fuel tank.
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These valves are your Idle control valve (green plug) and your air-con fast idle valve (purple plug)
If the air-con valve doesn't work it just means you don't have additional fast idle for running the air con system.
The Idle control valve doesn't work you're in trouble - it regulates your idle speed and compensates for extra load placed on the engine when you place it in "drive" (auto transmission) , when the engine is cold, and can even compensate for a failed air-con fast idle.
It regulates engine deceleration and has a "high vacuum bypass" built in which is a pain when you are trying to use engine braking compared to a direct throttle control system.
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This one is your "cold start" or "Air control valve" - (nissan speak) It hides underneath the inlet manifold and blocks access to the heater hoses, oil filter and oil pressure sender.
Unless you are living in the Snow country where it is regularly below 12 degC, this is just useless junk.
It operates on startup like the Auto choke on the carby tb42. A thermo spring opens an air valve to allow a faster idle than the (green plug) Idle control valve can allow by itself. 12v current taken from the fuel pump circuit, heats up the thermo spring to turn it off.
For most Aussies, this valve and it's pipes, brackets and hoses can be junked - the ECU doesn't even register it's missing.
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Here is the "cold start" valve on the floor along with it's vacuum hoses/pipes, water hoses to the inlet manifold (for heating the inlet manifold and throttle body to prevent "icing" - hardly a problem in Australia),
Also are the vacuum pipes for the brake and clutch booster (which for some reason go all the way across the firewall to the passenger side of the engine bay to the tiny vacuum booster reservoir, and then back across the firewall to the boosters - there is probably more capacity in the pipes than the reservoir)
Also are the original heater hoses, rusted out heater pipes and barb fittings.
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