Hi all, need some mechanical advice PLS, for my '83 Mondial QV, Durban, South Africa, regarding the Fuel Pressure Regulator: 1.My car was parked off for 4yrs due to overheating. Did minor service few months ago, with new fuel & water etc. but on any 1st startup , the plugs are fueling rich , & then car won't start again after leaving it to idle for about 3 mins. what should be the correct fuel pressure be on the FPR, in bar or psi.? 2.1 My new mech thinks , that the original FPR/ fuel pressure regulator may be faulty, and was hence bypassed previously by another mech. What damage/issue has this caused? 2.2 the car has been overheating for a long while, due to previous mechanics negligence, so i parked it off many years back. Before we look @ the head gasket, we trying to problem solve by process of elimination. Will a faulty FPR cause a overheating issue? 2.3 when the existing FPR is connected back, its staying open. Can it be fixed? Or is time for a replacement? 3. We want to install an aftermarket Fuel Pressure Regulator, are there options? Thank u kindly,
Prolonged disuse is very hard on Bosch CIS injection systems because of the many small clearances and orifices (so any small deposits/varnish that develop can muck things up). I'll assume by "fuel pressure regulator" that you mean the Warm-Up Regulator (WUR) or sometimes it is called the Control Pressure Regulator (which is very accurate because that's what it does -- it determines the control pressure). The system fuel pressure regulator is actually part of the fuel distributor. Based on you location, the closest shop to rebuild your WUR (or fuel distributor) would probably be in Europe (hopefully, some euro members will suggest some). The Mondial 8/QV WSM 281/83 in Chapter D has all the specs and information for your 1983 euro MondialQV K-Jet without Lambda Bosch CIS injection system -- see this link for a copy: https://www.dropbox.com/s/z99soo68ny9n2qa/Mondial8qv_workshop_281-83.pdf?dl=0
Based on the description, could also be the thermo time switch & cold start injector. Easy to test: just disconnect the bosh junior plug that feeds the injector after first startup.
What do you call FRP - please post a picture. Bypassing anything in the fuel injection system seems a very daring approach to solve a problem... This company rebuilt my K-Jet and they're on your side of the globe: https://k-jet.biz/ Send them your Fuel Distributor, Warm-up Regulator, Auxiliary Air Valve and Cold Start Injector. Clean up your air flow metering plate assembly and make sure it's moving smoothly, returning to the idle position as per the book. Your overheating issue is not linked to the fuel injection. Mondial QVs don't overheat. Mine would have if that was an issue with this type. Make sure you have a thermostat fitted (in case some genius removed it to "cure" an overheating issue) and both radiator fans run once the needle hits the first intermediate mark. Without thermostat the cooling system wont' work. One rad fan is limit when it's hot outside; it will go up right to the upper intermediate bar, which is uncomfortable. Years ago I had a new aftermarket thermostat come apart, blocking the coolant flow in the process. That did lead to a very quick heat buildup, shut down and a tow. No harm done to the engine luckily. You might want to check your coolant hoses and rad for blockages. Again, Mondials don't overheat. You don't need any trick coolant, special thermostat or high pressure cap. It will work the way it left the factory. If you need a good wiring diagram for your QV send me a PM.
There are two pressure regulators: the system pressure is adjusted by the flow meter and the control pressure that is adjusted by the WUR. Bypassing the system pressure valve would not make any sense (no return of excess flow to the tank seems a bad idea). It could be possible to "lock" control pressure (i.e the WUR) so has to have only single control pressure, but that would be quite a lot of work. An easier item to bypass would be the pressure accumulator, this is well documented on some Ford Capri forum. Makes hot-start a pain unless you also disconnect the safety switch... (Maybe not a good idea on a Ferrari).
Hot start problem on a CIS car is 80% of the time a vapor lock issue. That is caused by system pressure not holding for at least 20-30 minutes after shut down. The system pressure is usually controlled by the fuel accumulator. Very common item to fail as these cars get older. Second..do you know what version of injection your car has? If you look down to the left of the fuel distributor..do you see what looks like an injector? Usually they are a tan color top, with a black center section. When the car runs, is it "buzzing"? That little injector plays a major roll in fuel control if your car is equipped with it..
