Hello. I知 working on a 2000 Montero Sport for an older veteran. I知 a GM/Chevy guy so seeking some knowledge before trouble shooting. I知 helping him out, and there is a budget. The vehicle has 217K Miles, and runs good, no codes.

Issue when starting cold, is long cranking. It always fires and runs, but I feel as though it should fire quicker. My guess is fuel. I haven稚 put a fuel pressure gauge in it yet as I would like to know what I知 looking for when I do. I assume when key is turned to ON, the fuel pump should prime, then shut off, based on a time relay or rail pressure. Question, what is the priming method, and if not priming where to look. Second, what fuel pressures are normal?

 

On a full sized Montero, fuel pressure at idle should be around 38 PSI. With vacuum hose on fuel pressure regulator, pressure should go up to 50 PSI when revving up engine. I would think Montero Sport values will be in the same neighborhood. As far as pressure drop after engine off - there should not be significant drop down withing two minutes after turning off engine. If you do observe significant pressure drop, figure out which end of fuel supply system is leaking (supply or return) by pinching off those hoses after engine is turned off and watching the pressure change. This will indicate which way fuel is bleeding off and where the problem may be. Generally speaking is pressure drops off gradually, its ether a leaky fuel injector or fuel pressure regulator. If pressure drops rapidly immediately after engine shut off, you likely have a stuck check valve in the fuel pump.

 

Thanks for the info. I’ll report back when I get a gauge on it.

 

Ok, back home and working in Montero. I have no idea where the Schrader valve for the fuel rail is? Is there one? If so, is it the same as GM/Ford etc?

 

Montero (Mitsubishi in general) does not have one built into the system. You have to have an adapter that fits between high pressure line and fuel injector rail.

 

Thank you. I have no idea how old the fuel filter is, so going to replace that. When I have that off, I値l hook up to the line and read it from there.
Being such a common diagnostic procedure, I find it odd there is no service port to hook up to.

 

I think it's a testament to Mitsubishi engineers confidence in their work 😄